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DIY Stompboxes => Building your own stompbox => Topic started by: Thomeeque on June 03, 2011, 09:27:39 AM

Title: EM3207 (v1.1) - MN3207 based EHX Electric Mistress (9V) clone
Post by: Thomeeque on June 03, 2011, 09:27:39 AM
 Hi,

 As title says EM3207 is a loose clone of the original 9V EHX Electric Mistress chorus/flanger adapted for MN3207 BBD chip.

 (http://thmq.mysteria.cz/em3207/thumb/DSCN9611.JPG) (http://thmq.mysteria.cz/em3207/detail.htm?DSCN9611.JPG) (http://thmq.mysteria.cz/em3207/thumb/DSCN9609.JPG) (http://thmq.mysteria.cz/em3207/detail.htm?DSCN9609.JPG)
 
 ( full gallery (http://thmq.mysteria.cz/em3207/) )
 
 Additionally it features:


 More that year ago I did announce this project in 9V Electric Mistress retrofit with MN3007 (http://www.diystompboxes.com/smfforum/index.php?topic=78270.msg693551#msg693551) thread, but it was frozen for four months already at the time I did announce it (it needed some tweaking where I've got stuck and I had to switch myself to something more important for me at the time), but there were few requests recently in the retrofit thread and I had some time for it now, so I did defrost it and gave it try again. I have made some changes and I quite like the result now. Unfortunately I cannot say how close or far it is from the original EM (I don't own original EM nor have access to it), but it's a nice flanger with EM character definitely.
 
 (http://thmq.mysteria.cz/em3207/big/EM3207_v1.1_schematic_1280.gif)
 ( don't print this schematic, following PDF contains high-quality print version )

 EM3207_v1.1_Build_Instructions.pdf (http://thmq.mysteria.cz/em3207/build/EM3207_v1.1_Build_Instructions.pdf) (complete build instructions, *DRAFT1* at this moment)

 Hopefully I'll have a time to make some small audio demo over this weekend.

 More notes may come later, enjoy, T.

Title: Re: EM3207 (v1.1) - MN3207 based EHX Electric Mistress (9V) clone
Post by: GodSaveMetal on June 03, 2011, 10:57:24 AM
Thanks my Friend I have to make this project!!! it's a great pedal!!! I have the mistress with MN3007!!!! it sounds OK!!!
Title: Re: EM3207 (v1.1) - MN3207 based EHX Electric Mistress (9V) clone
Post by: quarara on June 03, 2011, 11:21:11 AM
Genius.
Title: Re: EM3207 (v1.1) - MN3207 based EHX Electric Mistress (9V) clone
Post by: StephenGiles on June 03, 2011, 11:46:26 AM
Excellent drawings, what is the advantage of having the additional two inverter buffers after the clock?
Title: Re: EM3207 (v1.1) - MN3207 based EHX Electric Mistress (9V) clone
Post by: Scruffie on June 03, 2011, 12:53:18 PM
Cheers Thomeeque! Didn't think you'd go to this much effort, I just wondered if you had a layout :D

Now to get this Through Zero Flanging in a 1590BB... Muwahahahaha... ahem.
Title: Re: EM3207 (v1.1) - MN3207 based EHX Electric Mistress (9V) clone
Post by: StephenGiles on June 03, 2011, 01:27:54 PM
Now Mike Irwin did get TZF with just one SAD1024 a few years back but the secret remained his.
Title: Re: EM3207 (v1.1) - MN3207 based EHX Electric Mistress (9V) clone
Post by: Fender3D on June 03, 2011, 01:58:02 PM
Now Mike Irwin did get TZF with just one SAD1024 a few years back but the secret remained his.
It shouldn't be an huge secret since SAD1024 is (better was?), actually 2x512 stages, each block with separate clock pins...  :icon_mrgreen:

BTW
great job, Tomas  :icon_cool:
Title: Re: EM3207 (v1.1) - MN3207 based EHX Electric Mistress (9V) clone
Post by: oldschoolanalog on June 03, 2011, 04:36:10 PM
OK. Who's going to be the first (not named Tomas) to try & verify?
Sorry, not me this time.
Nice work as always T. :icon_cool:
Now Mike Irwin did get TZF with just one SAD1024 a few years back but the secret remained his.
It shouldn't be an huge secret since SAD1024 is (better was?), actually 2x512 stages, each block with separate clock pins...  :icon_mrgreen:
Proximity of the clock lines to each other might lead to heterodyning issues when using an SAD1024 in such an arrangement. Somebody more knowledgeable might chime in here (hint; Stephen?).

@Luigi: Is everything OK on Sicily? With Mt. Etna erupting and all that...
Title: Re: EM3207 (v1.1) - MN3207 based EHX Electric Mistress (9V) clone
Post by: quarara on June 03, 2011, 05:42:24 PM

@Luigi: Is everything OK on Sicily? With Mt. Etna erupting and all that...

Well, we're used to it! :)
At any rate, these days the volcano is not really erupting, there is just a little bit of smoke coming from the highest craters that doesn't worry us.
Title: Re: EM3207 (v1.1) - MN3207 based EHX Electric Mistress (9V) clone
Post by: oldschoolanalog on June 03, 2011, 10:03:02 PM
@Tomas: How does this one compare to the (one of 3 in known existence :icon_lol:) EM1022 you designed a while back?
For those who are wondering what an EM1022 is:
http://thmq.mysteria.cz/em1022/EM1022_Build_Instructions.pdf
Thanks!
Title: Re: EM3207 (v1.1) - MN3207 based EHX Electric Mistress (9V) clone
Post by: StephenGiles on June 04, 2011, 09:44:02 AM
@Tomas: How does this one compare to the (one of 3 in known existence :icon_lol:) EM1022 you designed a while back?
For those who are wondering what an EM1022 is:
http://thmq.mysteria.cz/em1022/EM1022_Build_Instructions.pdf
Thanks!


Well - almost 5 actually, I built a couple of EM 1022s with "bounce" about 10 years ago. They were both the 2 battery circuit with one half of the 4013 used in the LFO. I gave one to my nephew and mine should be  - yes it's on the shelf in front of me!
Title: Re: EM3207 (v1.1) - MN3207 based EHX Electric Mistress (9V) clone
Post by: Thomeeque on June 04, 2011, 02:13:07 PM
 Thanks for all the compliments and interest, guys, I really appreciate that :) I'm short of time now, I'll add some comments later.. Cheers, T.
Title: Re: EM3207 (v1.1) - MN3207 based EHX Electric Mistress (9V) clone
Post by: azrael on June 11, 2011, 03:42:10 PM
awesome work! :D
Title: Re: EM3207 (v1.1) - MN3207 based EHX Electric Mistress (9V) clone
Post by: soundclone on June 11, 2011, 09:53:53 PM
i want to build this pedal,but i can find all tantalum cap in local store. can i substitute all tantalum cap with electrolyte cap?
Title: Re: EM3207 (v1.1) - MN3207 based EHX Electric Mistress (9V) clone
Post by: oldschoolanalog on June 11, 2011, 10:12:02 PM
Yes.
Title: Re: EM3207 (v1.1) - MN3207 based EHX Electric Mistress (9V) clone
Post by: soundclone on June 12, 2011, 04:55:06 AM
I'm sorry...i mean :
i want to build this pedal,but i CANT find all tantalum cap in local store. can i substitute all tantalum cap with electrolyte cap?
Title: Re: EM3207 (v1.1) - MN3207 based EHX Electric Mistress (9V) clone
Post by: oldschoolanalog on June 12, 2011, 06:05:26 AM
Yes!
Title: Re: EM3207 (v1.1) - MN3207 based EHX Electric Mistress (9V) clone
Post by: kranja on June 16, 2011, 02:26:35 AM
Great design, thank you very much. I will give it try even if  I'm quite a beginner. Could you give me some more details about the off board wiring of the toggle switches, what kind of toggle switches do I need, what are those caps on the photos (I'm not sure if I need only one DPDT switch as stated in the pdf or an additional spdt switch which I'm not sure where to connect)? Has somebody allready fitted this board in a 1590BB enclosure, will this kind of pots fit this box http://www.banzaimusic.com/Alpha-16-PC-ANG-10k-lin.html ?
Title: Re: EM3207 (v1.1) - MN3207 based EHX Electric Mistress (9V) clone
Post by: Thomeeque on June 16, 2011, 09:13:00 AM
Great design, thank you very much. I will give it try even if  I'm quite a beginner. Could you give me some more details about the off board wiring of the toggle switches, what kind of toggle switches do I need, what are those caps on the photos (I'm not sure if I need only one DPDT switch as stated in the pdf or an additional spdt switch which I'm not sure where to connect)?

 Hi, you're welcome :) Switch with caps you see on the photos is one of "ADVICED MODS" ("Play with C17 (clock cap)..") Just ignore it for this moment, build it and make it working without any mods first. There is only one switch in the basic version, mode switch (SW_MODE), it is DPDT switch and it's wiring is indicated on the schematic. OK, maybe this way it's more obvious:

 (http://thmq.mysteria.cz/em3207/build/sw_mode_DPDT_toggle_wiring.gif)

Has somebody allready fitted this board in a 1590BB enclosure, will this kind of pots fit this box http://www.banzaimusic.com/Alpha-16-PC-ANG-10k-lin.html ?

 Looks like this (http://www.alphapotentiometers.net/html/16mm_pot_4.html) type. There's only 16-9.3-4.9=1.8mm space between PCB and back of pot. You need at least 8mm (height of the IC in the precise socket) space there. Either look for more suitable pot type* or you may try to straighten legs and bend them as close to pot body as possible like this:

 (http://thmq.mysteria.cz/em3207/build/alpha-16mm-4-mod.gif)

 This way you should theoretically gain 5.2mm, remaining 1mm you could gain by using shim (I'm not sure it's best word for what I mean, but it should be obvious from the picture) between PCB and the indention on pots leg (there should remain at least 1.5mm of the leg on soldering side of PCB for propper joint).

 Good luck, T.

* Edit: Ask ~arph (http://www.diystompboxes.com/smfforum/index.php?topic=36392.msg788895#msg788895) :)
Title: Re: EM3207 (v1.1) - MN3207 based EHX Electric Mistress (9V) clone
Post by: Mark Hammer on June 16, 2011, 10:53:45 AM
First, for doing all the work to redesign the circuit and board to accommodate a 3207.  Very much appreciated.  Not just by me, but by many others, I'm sure.

Second, the layout is very compact.  Compact enough, that a person could consider shoving two of them in the same pedal.  This creates some interesting possibilities.

First, there is the obvious possibility of splitting a mono input signal and having two asynchronous flanger outputs.
Second, there is the possibility of having a mixer and combining the two flanger signals into a single more complex mono output.
Third, there is the possibility of lifting the dry signal from each flanger outputs, and running them "stereo-out" to separate amps or mixer channels.  At slow sweep speeds, this can produce both apparent movement as the phase relationship between left and right keeps changing.  It can also produce "flanging in-air" (though that likely requires standing in the sweet spot).  At faster sweep speeds, you get stereo vibrato, which can be interesting.
Fourth, with dry lift, and setting one of them to "filter matrix" (non-swept) mode, combining flanger A and B gets you variations of through-zero flanging.

Clearly, throwing a pair of these into a suitably-sized chassis, that can accommodate both boards, a splitter/mixer board, additional jacks and toggles, can yield something truly wonderful.
Title: Re: EM3207 (v1.1) - MN3207 based EHX Electric Mistress (9V) clone
Post by: Scruffie on June 16, 2011, 12:00:28 PM
First, for doing all the work to redesign the circuit and board to accommodate a 3207.  Very much appreciated.  Not just by me, but by many others, I'm sure.

Second, the layout is very compact.  Compact enough, that a person could consider shoving two of them in the same pedal.  This creates some interesting possibilities.

First, there is the obvious possibility of splitting a mono input signal and having two asynchronous flanger outputs.
Second, there is the possibility of having a mixer and combining the two flanger signals into a single more complex mono output.
Third, there is the possibility of lifting the dry signal from each flanger outputs, and running them "stereo-out" to separate amps or mixer channels.  At slow sweep speeds, this can produce both apparent movement as the phase relationship between left and right keeps changing.  It can also produce "flanging in-air" (though that likely requires standing in the sweet spot).  At faster sweep speeds, you get stereo vibrato, which can be interesting.
Fourth, with dry lift, and setting one of them to "filter matrix" (non-swept) mode, combining flanger A and B gets you variations of through-zero flanging.

Clearly, throwing a pair of these into a suitably-sized chassis, that can accommodate both boards, a splitter/mixer board, additional jacks and toggles, can yield something truly wonderful.
I tried running an Electric Mistress in Filter Matrix into another Flangers With the Same Audio Path as the Mistresses Send & Return and to be honest, it didn't work all that wonderfully... I think it'd need some refinement.
Title: Re: EM3207 (v1.1) - MN3207 based EHX Electric Mistress (9V) clone
Post by: Fender3D on June 16, 2011, 01:29:35 PM
To achieve what Mark said, you must connect the 2 flangers in parallel, not in series,
then you'll need to find a way to lift the dry signal
Title: Re: EM3207 (v1.1) - MN3207 based EHX Electric Mistress (9V) clone
Post by: Scruffie on June 16, 2011, 04:25:57 PM
To achieve what Mark said, you must connect the 2 flangers in parallel, not in series,
then you'll need to find a way to lift the dry signal
I had them in parallel, but now that you mention it... i'm not sure I did kill the dry signal, it was a while ago, i'll have to go back and try it again.
Title: Re: EM3207 (v1.1) - MN3207 based EHX Electric Mistress (9V) clone
Post by: trat rödenback on July 02, 2011, 08:48:22 AM
WOW! Great Project! I allready got all the Parts for the EM with mn3007 (Jorge's Layout) but this Layout is so much more compact. I'd definitely like to build the EM3207. How does it sound compared to the mn3007 version? Is there a big difference?
Title: Re: EM3207 (v1.1) - MN3207 based EHX Electric Mistress (9V) clone
Post by: Mark Hammer on July 02, 2011, 11:15:16 AM
To achieve what Mark said, you must connect the 2 flangers in parallel, not in series,
then you'll need to find a way to lift the dry signal
I had them in parallel, but now that you mention it... i'm not sure I did kill the dry signal, it was a while ago, i'll have to go back and try it again.
Through-zero requires that the delayed signal be able to achieve a "negative" delay; i.e., a delay time that is less than the dry signal.  If your dry signal is simply a buffered input, then clearly this is not physically possible, even for Dr. Who.

HOWEVER, if you are able to delay the dry signal, by just a couple of milliseconds (and often, as little as 1-2msec), the swept-delayed signal will, at some point, achieve a delay time which is actually less than the fixed delay of your "dry" signal.  If those two are produced in parallel and mixed, you get through-zero flanging.  If they are placed in series, then all you do is add the delay time of the one to the other, which only gets you poorer flanging.
Title: Re: EM3207 (v1.1) - MN3207 based EHX Electric Mistress (9V) clone
Post by: oldschoolanalog on July 02, 2011, 12:58:20 PM
...then clearly this is not physically possible, even for Dr. Who.
:icon_lol: :icon_lol: :icon_lol:
Title: Re: EM3207 (v1.1) - MN3207 based EHX Electric Mistress (9V) clone
Post by: Keppy on July 05, 2011, 01:51:06 AM
I just discovered the scarcity of the SAD1024 last week and was lamenting that the 3207 version was not complete. Turns out it was, but I just noticed today. Thanks Thomeeque!
Title: Re: EM3207 (v1.1) - MN3207 based EHX Electric Mistress (9V) clone
Post by: HarryBBD on July 05, 2011, 10:20:31 AM
RE: Mike Irwin TZF
(where is Mike these days, BTW ?)

Its possible to use a fixed, analog delay (dome filter) for one audio path and the BBD for the other. A dome filter is a bunch a stagger-tuned
all pass filter stages (more commonly known as 'phase shift' stages) Choose the right values and there is a slight audio delay that is reasonably
flat for a wide audio range. Juergen Haible of synth-diy has some schematics online for his frequency shifter. The dome filter gives two
outputs that are 90 degrees apart (sine-cosine). You only need half of this circuit for it to work, but probably you'd need at least six opamp
stages to make it work well enough. Each stage is three resistors, an op amp, and one capacitor.
Title: Re: EM3207 (v1.1) - MN3207 based EHX Electric Mistress (9V) clone
Post by: oldschoolanalog on July 05, 2011, 11:56:42 AM
http://www.diystompboxes.com/smfforum/index.php?topic=25168.0
 :icon_eek:
Also:
http://www.diystompboxes.com/smfforum/index.php?topic=77987.0
 ;)
Title: Re: EM3207 (v1.1) - MN3207 based EHX Electric Mistress (9V) clone
Post by: Mark Hammer on July 05, 2011, 12:46:55 PM
I think the most trivial and easy access to through-zero flanging these days is to simply buy a Behringer DC-2 clone ( http://www.behringer.com/EN/Products/CC300.aspx ), and lift the dry signal from the two delay paths like Scott Stites did:  http://www.birthofasynth.com/Scott_Stites/Pages/dimc_main.html
Title: Re: EM3207 (v1.1) - MN3207 based EHX Electric Mistress (9V) clone
Post by: Thomeeque on July 07, 2011, 05:27:52 PM
 Hi fellas,

 thanks again for your compliments, ideas, questions, discussion etc. :)

 I'm sorry I don't respond very much, but I'm still kinda busy..

 Anyway, I have some news (both good and no so good)..

 I've got finally my hands on the real vintage Electric Mistress with SAD1024 chip! It's a Deluxe not the Standard version, but since 9V EM is SEM/DEM hybrid actually ("standard" audio path, rest is deluxe, more or less), it is pretty useful too.

 (http://thmq.mysteria.cz/em3207/thumb/DSCN9624.JPG) (http://thmq.mysteria.cz/em3207/detail.htm?DSCN9624.JPG)(http://thmq.mysteria.cz/em3207/thumb/DSCN9630.JPG) (http://thmq.mysteria.cz/em3207/detail.htm?DSCN9630.JPG)

 It was an "eyeopener" for me in many ways and it made me start a new round of EM3207 R&D (actually I did plan to do some tweaking of rev1.1 yet anyway, but comparison with the real piece moved it to another level).

 Biggest difference is definitely sweep range (and sweep character). EM3207 1.1's maximal range hardly touched DEM's minimal.

 I did measure control voltage range at clock VCO (http://thmq.mysteria.cz/em3207/build/DEM_VCO_640.gif) and it's V-f characteristic:
 
 (http://thmq.mysteria.cz/em3207/thumb/DEM15V_clock_sweep.gif) (http://thmq.mysteria.cz/em3207/detail.htm?DEM15V_clock_sweep.gif)


 So the delay time range goes from 8.83 to 0.20ms which makes max/min ratio 44:1!! :o

 And btw., since VCTRL sweep are linear triangles, frequency sweep is HYPER-TRIANGULAR! Oh yeah - that's why we love EM so much, I just did not see it that clearly up to now :)

 I've made two samples with maximal range, lowest rate and no feedback (color):

 DEM15_noise.wav (http://thmq.mysteria.cz/em3207/wav/DEM15_noise.wav)
 DEM15_shine.wav (http://thmq.mysteria.cz/em3207/wav/DEM15_shine.wav)

 EM3207 v1.1's maximal ranges were pathetic compared to this (e.g. 271~1245kHz at one particular setting), max/min ratio was cca 5:1~7:1 depending on C17 and clock trim setting, and maximal frequency I was able to get out of it was cca 1250kHz (above this limit 4013 failed to read 311's output and 4013's outputs were frozen) which equals only to 625kHz of DEM (0.41ms, we have BBD twice longer!), plus sweep did not sound that pleasant when clock were adjusted to this range, like if it would slow down at the top (now I know that sweep curve was loosing it's hypertriangularity).

 So heavy R&D started again :) Since then I am tweaking my EM3207 prototype:

 (http://thmq.mysteria.cz/em3207/thumb/DSCN9658.JPG) (http://thmq.mysteria.cz/em3207/detail.htm?DSCN9658.JPG)

 emulating VCO in LTSpice:

 (http://thmq.mysteria.cz/em3207/thumb/DEM15V_clock_LTC.gif) (http://thmq.mysteria.cz/em3207/detail.htm?DEM15V_clock_LTC.gif)

 and I have even built the standalone replica of the clock to be able to study more comfortably and safely influence of all possible factors including e.g. VCC (you know, EM3207 cannot be fed by more then 10V and I've wanted to see what's going on with VCC = 12 or 15V):

 (http://thmq.mysteria.cz/em3207/thumb/DSCN9728.JPG) (http://thmq.mysteria.cz/em3207/detail.htm?DSCN9728.JPG)

 :icon_mrgreen:

 All of this to get the EM3207 clock working as close to DEM with doubled frequency as possible ::) I did break original 311 to 4013 transition top limit relatively easily (actual "record" for fCLOCK is 2.1MHz, eventually 2.7MHz), but just to find that lowering value of the clock capacitor is not the way, that other parts have it's limits too (including LM311N, those 2.7MHz I did achieve with old Tesla MAB311 equivalent) etc., it is really long story and it's not over.

 Here's the best what I've achieved so far (Tesla MAB311 used, same setting as for DEM15):

 EM3207_noise.wav (http://thmq.mysteria.cz/em3207/wav/EM3207_noise.wav)
 EM3207_shine.wav (http://thmq.mysteria.cz/em3207/wav/EM3207_shine.wav)



 Just to calm down all those who already started to build original EM3207 v1.1 - all those tweaks should be posible using v1.1 PCB, it should be (so far it is) just about different values of some components mostly. And actually, even original EM3207 v1.1 sound pretty good ;)



 Cheers, T.

 Note: pics are clickable for hi-res.
Title: Re: EM3207 (v1.1) - MN3207 based EHX Electric Mistress (9V) clone
Post by: Mark Hammer on July 07, 2011, 07:19:21 PM
Thanks, Tomas, for all the hard work, and especially your conscientiousness and willingness to continue.

Yes, when it comes to flangers, the sweep ratio is VERY important!  Let's hope that somethng in the right direction can be achieved with a 9v supply.
Title: Re: EM3207 (v1.1) - MN3207 based EHX Electric Mistress (9V) clone
Post by: 12Bass on July 07, 2011, 09:27:23 PM
FWIW, while flanging using short delay times is audible on a full-range signal, I've found that delay times shorter than ~ 0.5 ms aren't very audible with an instrument like a guitar, making it of questionable value to push the clock much higher.  From the clips, I think that I might prefer the original DEM15 over the EM3207 version - sounds a bit fatter and more dramatic; it could be a matter of calibration, however.  Perhaps the DEM15 is adjusted closer to 50/50 and getting more complete cancellation?  Both sound as if they are accelerating as they sweep up, though the LFO waveforms might sound a little different.  I've spent some time trying to "smooth out" the sweep on my A/DA clone, as it tends to go through the upper part of the sweep more quickly than I'd prefer.  

Nice work!  I've got some MN3007s around which might be good for a similar project.  Curious to see/hear how this progresses....
Title: Re: EM3207 (v1.1) - MN3207 based EHX Electric Mistress (9V) clone
Post by: Thomeeque on July 08, 2011, 05:37:00 AM
Thanks, Tomas, for all the hard work, and especially your conscientiousness and willingness to continue.

 Thanks, Mark :)

Yes, when it comes to flangers, the sweep ratio is VERY important!

 Ratio and sweep course, I'd say..

 Let's hope that somethng in the right direction can be achieved with a 9v supply.

 I run all my analog pedals at 10V (it's closer to fresh 9V battery ;)), but I did try to run EM3207 at 9V too, there's almost no difference.

FWIW, while flanging using short delay times is audible on a full-range signal, I've found that delay times shorter than ~ 0.5 ms aren't very audible with an instrument like a guitar, making it of questionable value to push the clock much higher.

 Well, IMO (!) the trick is in synergy of the big range (going from very reasonably low to very high clock) and hypertriangular sweep, which sweeps the highest clock range quickly (as you can see from V-f graph, more then 90% of the sweep time is above 0.5ms). It's not necessary there, especially if you want just decent light flange, but for "jet-plane" effect it would be missing..

From the clips, I think that I might prefer the original DEM15 over the EM3207 version - sounds a bit fatter and more dramatic; it could be a matter of calibration, however.  Perhaps the DEM15 is adjusted closer to 50/50 and getting more complete cancellation?

 DEM15 sounds fatter because of different audio path, 9V EM cuts lot of lows, so it sounds much more midrange (which can be actually better in full band mix), it could be adjusted to taste by using bigger caps in the output mixer (C10, C8).

 About more dramatic I'm not sure (could be partially equalisation metter as well). But yes, cancellation may play the role here - even IMO not that major (I have 8k2+trimmer there now for R18 and there's not that much difference, if it's adjusted to 8k2 or to e.g. 12k).

 Btw. absolute cancellation is something you cannot achieve in full clock range (even with SAD1024), gain of BBD is fCLOCK dependant. But in the case of EM3207 more as we go to higher clocks - it is another issue which I may try to address yet later (those 512 cells more really suck :)).

 Btw. I did measure GAIN-fCLOCK characteristic for EM3207 v1.1 as well:

 (http://thmq.mysteria.cz/em3207/thumb/EM3207_gain_at_R15.gif) (http://thmq.mysteria.cz/em3207/detail.htm?EM3207_gain_at_R15.gif)

 GAIN here represents ratio of voltage at Q1 emitter and voltage at BBD input (200Hz 2VPP sine).

 I'd say that used clock buffer does good job, I wonder how would Ultra Flanger's buffer behave here..? I did choose used configuration over UF long time ago based on resume of some discussion I've googled (probably at this forum), but it could be interesting to dig again..

 For DEM15 I did just quick measurement so far, BBD gain was 1.06@33kHz and 0.92@663kHz (plus I have note there, that gain drop starts at 130kHz).

 Both sound as if they are accelerating as they sweep up, though the LFO waveforms might sound a little different.

 Both samples are made in the FLANGE mode (though the LFO waveforms)!

 And yes, "Both sound as if they are accelerating as they sweep up", that's the goal = that's what is hypertriangularity about :)

 I've spent some time trying to "smooth out" the sweep on my A/DA clone, as it tends to go through the upper part of the sweep more quickly than I'd prefer.  

 Looks like we have oposite tastes :) But actually, with lower range it's not that dramatic plus there are ways how to simply lower this effect in case of EM3207.

Nice work!  I've got some MN3007s around which might be good for a similar project.  Curious to see/hear how this progresses....

 Thanks! :)
Title: Re: EM3207 (v1.1) - MN3207 based EHX Electric Mistress (9V) clone
Post by: 12Bass on July 08, 2011, 10:53:40 AM
The 4049 buffer in your circuit appears to be very similar to the one used in the A/DA flanger clone.  From what I recall in earlier threads, measured performance was worse when using three inverter stages (like Ultra Flanger).  Even with a 4049 buffered SAD1024, IIRC, there's a roughly 2dB delta in gain between the shortest and longest delay settings; MN-series may be somewhat worse (or perhaps better, if your graph indicates less than 0.4 dB and not 0.4 V difference).  I also noticed that it is impossible to adjust for maximum cancellation throughout the entire sweep, so RTA was used to set the BBD output so that maximum comb filtering was centered in the "sweet spot", somewhere in the upper-middle of the sweep.  Some designs incorporate a transistor buffer at the BBD output which is supposed to improve linearity at higher clock rates. 

I don't have measurements handy at the moment, but I seem to recall from earlier testing that the flanging effect was mostly lost when the cancellation of the fundamental rose above around 2 kHz, which I thought was more than 0.4 ms.  Above that point, even with the extended bandwidth in my build, there simply wasn't much signal left to audibly flange, except if the source was full-range with a fair amount of high frequency content and when listening through a full-range playback system.  Then there's the issue of less dramatic comb filtering due to the loss of BBD gain at higher clock speeds.  From what I recall, my A/DA can sweep to less than 0.3 ms; however, I've found that when sweeping that high, the flanging effect disappears pretty easily, so I usually tend to reduce the sweep range to less than half of maximum in order for it to be musically useful.  Put another way, I've found that a huge sweep range is cool to have at your disposal... but it can easily be too much unless you're listening to the flanger sweep through a full-range signal in a controlled setting.  It's easy to set the sweep so high that you can barely hear any flanging in the top range. 

From the look of it, the DEM does not have the lower (~15 ms) range of the A/DA, though that may help keep it from sounding too metallic.  That delay lower range can be nice for chorus sometimes, or to make robot voice regeneration sounds.  The SAD1024 also gets noticeably more noisy when the delay exceed ~10 ms.  If I had to guess, I'd say that the most musically useful flanging range lies somewhere between 0.5 and 5 ms.   

Wish I had the actual figures handy.  I could go back and record some proper measurements if it would be helpful.  I think that I did the clock/frequency calculations previously out of curiosity, but didn't write anything down.

In case you missed it, here's an earlier thread with RTA plots showing the comb filtering at various settings (after setting the output trim for maximum cancellation):

http://www.diystompboxes.com/smfforum/index.php?topic=91378.0

 
Title: Re: EM3207 (v1.1) - MN3207 based EHX Electric Mistress (9V) clone
Post by: Mark Hammer on July 08, 2011, 11:27:59 AM
FWIW, while flanging using short delay times is audible on a full-range signal, I've found that delay times shorter than ~ 0.5 ms aren't very audible with an instrument like a guitar, making it of questionable value to push the clock much higher.  From the clips, I think that I might prefer the original DEM15 over the EM3207 version - sounds a bit fatter and more dramatic; it could be a matter of calibration, however.  
I find the "drama" of a flanger is a function of its transition from no apparent/audible notches to being "infected" with notches.  So, you are quite correct that the naturally occurring bandwidth of a guitar signal can make a flanger sound inoperable at the short-delay end of the sweep, if you aim for spectacularly short delays.  At the same time, I suspect the impact of those short delays is that the sweep may appear to spend a conspicuously long time "not doing anything audible".

There are two ways you can look at this.  One is to calibrate the delay-range so that it doesn't go beyond those audible inflection points.  The other is to alter the LFO waveform so that the sweep doesn't spend an inordinate amount of time on the "wrong side" of that inflection point.  The schematic shown here - http://hammer.ampage.org/files/hypertriangleclock.gif - is a simplification of an earlier circuit that used the FET+diodes arrangement to produce a sine wave approximation from a standard LFO triangle output.  That original had used diodes running to both drain and source from gate to derive a sine wave, and FWR'd that to produce a hypertriangular wave.  The McConkey circuit took a shortcut and uses just a single diode with the FET to produce a sinusoidal shape at one peak of the waveform, and retain the triangular shape at the other.  I wonder if one could use some arrangement of that to adjust the degree of sinusoidal shape at that end of the sweep, such that if the width/sweep was going to go beyond that ideal inflection point, you could shorten how much time the sweep spent on the other side of it.

Does that make sense?
Title: Re: EM3207 (v1.1) - MN3207 based EHX Electric Mistress (9V) clone
Post by: Govmnt_Lacky on July 08, 2011, 12:17:20 PM
Phewww! I'm glad I waited on this one. I was just gearing up for this build  :icon_lol:

Just a thought... would an investigation into the Ibanez FL9 lend any help to this? It uses the MN3207/MN3102 combo in the flange circuit.  ???

Here is the info:

http://www.diystompboxes.com/smfforum/index.php?topic=68966.0

Just finished building this and I must say... I am impressed with it! It does a great job... ya know..... not being an MXR M117 and all  :icon_rolleyes:
Title: Re: EM3207 (v1.1) - MN3207 based EHX Electric Mistress (9V) clone
Post by: Mark Hammer on July 08, 2011, 12:46:51 PM
Note that the Boss BF-2 doesn't have a sweep range much wider than what Tomas was disappointed to see in V1.1.  And from the little I can tell, the BF-2 has a straightforward triangular sweep.  So even if this 3207-based EM does not eventually manage to attain the grand sweeps of its 1024-based ancestor, building it will still probably get you a reasonable BF-2 workalike that  sounds good.
Title: Re: EM3207 (v1.1) - MN3207 based EHX Electric Mistress (9V) clone
Post by: 12Bass on July 08, 2011, 01:06:12 PM
Judging by the samples, the MN3207 EM is sweeping higher than a BF-2 can.   

What I gather is that the audibility of the flanging effect rapidly decreases when the lowest notch is greater than the highest fundamental frequency of the source signal.  With a guitar, once the comb filtering starts above the fundamental frequency of the the highest note (1175 Hz), the sweep begins to effectively disappear, as it can only effect the higher harmonic overtones.  At 2350 Hz, the flanger would be cancelling the second harmonic of the highest note.  So, the size of the "black hole" at the top of the sweep would seem to be dependent upon the highest fundamental of the source, plus its upper harmonic content (e.g. a square wave fuzztone, which could have harmonics going to infinity and beyond...).  If there's no appreciable upper-harmonic content, the flanger is effectively flanging "air".     
Title: Re: EM3207 (v1.1) - MN3207 based EHX Electric Mistress (9V) clone
Post by: Mark Hammer on July 08, 2011, 01:47:47 PM
And this is precisely why the benchmark flanger sounds over the years have been post-production flanging applied to multi-source mixes, where the bandwidth is wide and full.  People hear those and thnk somehow they"re going to get the same magic throwing a flanger at a single measly guitar.  Sorry, folks, doesn't work that way.  :icon_frown:
Title: Re: EM3207 (v1.1) - MN3207 based EHX Electric Mistress (9V) clone
Post by: oldschoolanalog on July 08, 2011, 01:48:16 PM
On a somewhat related note...
The A/DA Flanger (the real one; not one of the clones) never used the 4049 buffer in any of it's incarnations (SAD1024 or MN3010). As far as I'm concerned; being an owner of one; it is still the benchmark/standard of what a guitar flanger should be. And I have loads of other units to compare it to. Clones & originals. All sorts of makes & models. I think Dave Tarnowski knew exactly what he was doing; not buffering the the clocks. And yes, I realize it is a 512 stage device.
And... With all due respect, the BF2 is a GPS device (Genuine Piece of S#!t [OK, it is durable :icon_rolleyes:]). If you're comparing anything you design to it you should go back to the drawing board & do some more serious R&D. To make a BF2 sound alike (or a "bit better") is a waste of time & resources, IMHO. An MXR 117 clone is a MUCH better choice to clone & mod to extend the sweep ratio.
My 2 cents.
When I get done w/all my court appearances (child support, divorce), I'll get with it & do some serious R&D and compare notes with Tomas and the gang. :icon_cool:
Peace y'all. :icon_lol:

PS: @Mark Hammer: If you finish your Anderton HF&C; I'll move this to the front of my bench and finish it ASAP:

http://i175.photobucket.com/albums/w121/oldschoolanalog/DSC01402.jpg

Title: Re: EM3207 (v1.1) - MN3207 based EHX Electric Mistress (9V) clone
Post by: 12Bass on July 08, 2011, 02:00:41 PM
Would be interesting to compare the A/DA with and without the clock buffer.  From everything I've read, the buffer should offer an improvement at the highest clock rates, so I'm unsure how/why an unbuffered design might sound "better". 

FWIW, when I was calibrating my A/DA clone, I played around with the highest clock, setting it to sweep into the cymbals on rock recordings.  It sounded cool sweeping way up there at the time, but I found those super short delay times were practically inaudible with guitar/bass, so I ended up lowering the maximum clock rate to a more usable range.

Definitely curious about the Anderton design.  Some serious thought went into that one....
Title: Re: EM3207 (v1.1) - MN3207 based EHX Electric Mistress (9V) clone
Post by: Govmnt_Lacky on July 08, 2011, 02:02:04 PM
And... With all due respect, the BF2 is a GPS device (Genuine Piece of S#!t [OK, it is durable :icon_rolleyes:]). If you're comparing anything you design to it you should go back to the drawing board & do some more serious R&D. To make a BF2 sound alike (or a "bit better") is a waste of time & resources, IMHO. An MXR 117 clone is a MUCH better choice to clone & mod to extend the sweep ratio.
My 2 cents.

I agree about the "quality" of the devices that you are comparing HOWEVER, when we get to reality and see that you can build an entire pedal (i.e. BF-2, FL9, etc.) utilizing the 3207 for the same price as one IC (SAD1024) for the A/DA or M117 then I can see why most people would go that direction.
Now, being someone who has cloned both the FL9 and the M117... I can say hands down that the M117 is absolutely a better flanger in all respects BUT, for the price.. the FL9 is pretty decent as well.

Just my 2 cents  ;D
Title: Re: EM3207 (v1.1) - MN3207 based EHX Electric Mistress (9V) clone
Post by: oldschoolanalog on July 08, 2011, 02:26:14 PM
You get what you pay for.
"No free lunch."
My $1 statement for the day. :icon_biggrin:
@Govmnt_Lacky: Need quality BBD's (name your flavor/any colour you like)? Still have those Germs? PM me ;).
edit: just saw; too late!
Title: Re: EM3207 (v1.1) - MN3207 based EHX Electric Mistress (9V) clone
Post by: Thomeeque on July 08, 2011, 07:53:11 PM
 Sorry, just briefly for now, I need to pack for my vacation and go to sleep :)

The 4049 buffer in your circuit appears to be very similar to the one used in the A/DA flanger clone.

 Same, actually :)

 From what I recall in earlier threads, measured performance was worse when using three inverter stages (like Ultra Flanger).

 OK, thanks!

 Even with a 4049 buffered SAD1024, IIRC, there's a roughly 2dB delta in gain between the shortest and longest delay settings; MN-series may be somewhat worse (or perhaps better, if your graph indicates less than 0.4 dB and not 0.4 V difference).

 Gain on that graph is just absolute UOUT/UIN ratio, not even recalculated to decibels (no dB, no V :))

 In dB it looks like this:

 (http://thmq.mysteria.cz/em3207/thumb/EM3207_gain_at_R15_dB.gif)

 Unfortunately I did not measure it above 2MHz yet, it will be probably somewhere at -2dB at 2.7MHz (I don't plan to go above 2.6MHz, 2x1280kHz is what I need max :)).

 OK, 4~5dB drop is far from perfect, but even if it would not be possible to make it better, I could live with that..
 
Judging by the samples, the MN3207 EM is sweeping higher than a BF-2 can.

 EM3207's sweep range at those samples is practically same as DEM15's already (cca 55kHz ~ 2.4MHz = 0.21ms ~ 9.3ms)..

 More later, cheers, T.
Title: Re: EM3207 (v1.1) - MN3207 based EHX Electric Mistress (9V) clone
Post by: 12Bass on July 09, 2011, 04:01:32 AM
John Roberts, who designed many BBD circuits in the 1970s,  offered some suggestions in this post:  http://www.gearslutz.com/board/6693261-post27.html
Title: Re: EM3207 (v1.1) - MN3207 based EHX Electric Mistress (9V) clone
Post by: ORK on July 10, 2011, 04:29:43 AM
John Roberts, who designed many BBD circuits in the 1970s,  offered some suggestions in this post:  http://www.gearslutz.com/board/6693261-post27.html

Your J. Roberts there talks about Craig.Anderton as a "dead man"
Quote
(RIP)
 

Tell you what: C.A. has been active this very morning on Harmony Central where he is the admin.  Elsewhere recently: http://twitter.com/#!/Craig_Anderton
Title: Re: EM3207 (v1.1) - MN3207 based EHX Electric Mistress (9V) clone
Post by: 12Bass on July 10, 2011, 05:20:20 AM
My guess is that Mr. Roberts had Craig Anderton confused with Stephen St. Croix, who designed the Marshall Time Modulator.  Anyway, from what I gather, John Roberts has pretty serious technical chops. 
Title: Re: EM3207 (v1.1) - MN3207 based EHX Electric Mistress (9V) clone
Post by: 12Bass on July 10, 2011, 07:59:38 AM
Just made some rough measurements comparing my A/DA clone with the Classic Flanger VST plugin which has a digital readout of delay time.  For comparison, I turned off modulation and set the VST flanger for high feedback, then played white noise and dialed the A/DA to match the pitch.  At the shortest delay, it is just slightly less than 0.2 ms, about half of the original A/DA specification of 0.4 ms.  So, my flanger sweeps about an octave higher.  It will go even higher than that, but I found that the volume drop was more noticeable, plus there's not much left up there to flange.   I set the low end for 13 ms, as I found that it wasn't musical sounding going much longer than that. 

With a 512-stage BBD line, giving 256 samples, the maximum clock rate was calculated to be 1.28 Mhz, while the minimum is 19.7 kHz.  However, because the two sections are used in parallel-multiplex, the effective sampling rate is actually twice that, as there are double the number of samples per clock cycle (2 x 256 = 512).  So, the maximum effective sampling rate is 2.56 Mhz, while the minimum is 39.4 kHz.  Note that the latter clock rates would be the same as a 1024-stage BBD, which also provides 512 samples.  I'm somewhat curious to test the impact of the 4049 buffer, to see how it affects higher clock rates, though perhaps it is best to leave it alone, now that everything is working so nicely.

As for the BF-2, it is only rated for 1 ms minimum... which is about where things start to sound interesting.  A flanger with a minimum delay of 0.2 ms would sweep over two octaves higher.  One of my favorite flanging sounds is sweeping up through the 0.4 to 1 ms region and back down to the lower ranges, which can have a cool "screaming" effect when a moderate amount of regeneration is added.  The BF-2 is incapable of reproducing this effect.
Title: Re: EM3207 (v1.1) - MN3207 based EHX Electric Mistress (9V) clone
Post by: Ben N on July 10, 2011, 09:25:49 AM
Note that the Boss BF-2 doesn't have a sweep range much wider than what Tomas was disappointed to see in V1.1.  And from the little I can tell, the BF-2 has a straightforward triangular sweep.  So even if this 3207-based EM does not eventually manage to attain the grand sweeps of its 1024-based ancestor, building it will still probably get you a reasonable BF-2 workalike that  sounds good.
No offense, but a BF-2 is to an EM as Hamburger Helper is to filet mignon (IMHO).
Title: Re: EM3207 (v1.1) - MN3207 based EHX Electric Mistress (9V) clone
Post by: 12Bass on July 10, 2011, 09:44:37 AM
Comments from Mike Irwin on the 4049 buffer:

http://archive.ampage.org/threads/4/fxgd/104868/ADA_Flanger_calibration-4.html

"Hi Dave, 
Thanks for putting those scope shots up! Nice to see. The observed rise/fall times for the SAD are shorter, as expected, due to less loading of the 4047 (assuming a 4047 is in the circuit...I have not seen an SAD-based A/DA schematic). The 4049 buffer in my modified clone reduces the rise/fall times considerably so they are within spec for the SAD. To my ears, there is a noticeable inprovement in the sound - better clarity - at the normal delay settings. I have clocked the SAD at up to 2.5 Mhz (meaning the internal osc of the 4047 is running at 5 MHz) which gives very short delays - without the 4049 the clock signal is very rounded with decreased amplitude. The MN3101/MN3102 clock chips are nice to use to drive any BBD as they have substantial drive ability compared to the more typical CD4013B approach. Now for the big question: is there much of a sonic difference between the two units (in-spec MN3010 vs. out-of-spec SAD)?"

http://www.diystompboxes.com/smfforum/index.php?topic=72329.msg585416;topicseen#msg585416

"I would have liked to use the 4049 inverters set up as two groups of
three paralleled inverters - but the 4047 is not able to drive the
combined gate input capacitance very well... so the technique shown has
been used as a compromise to preserve good rise/fall times."

Title: Re: EM3207 (v1.1) - MN3207 based EHX Electric Mistress (9V) clone
Post by: oldschoolanalog on July 10, 2011, 10:17:52 PM
No offense, but a BF-2 is to an EM as Hamburger Helper is to filet mignon (IMHO).
But it's DURABLE man! (See ill my ill natured/opinionated post above :icon_lol: )
OK, OK. No more BS, uh, I mean BF2 bashing.
Now the BOSS BF1 (Big Blue). There's a nice (guitar) flanger!

@12Bass: Mr. Roberts summed it up best in his last sentence. If it sounds good, it is good... Nice link BTW; thanks!
Title: Re: EM3207 (v1.1) - MN3207 based EHX Electric Mistress (9V) clone
Post by: Mark Hammer on July 11, 2011, 09:16:50 AM
No offense, but a BF-2 is to an EM as Hamburger Helper is to filet mignon (IMHO).
But it's DURABLE man! (See ill my ill natured/opinionated post above :icon_lol: )
OK, OK. No more BS, uh, I mean BF2 bashing.
Now the BOSS BF1 (Big Blue). There's a nice (guitar) flanger!

@12Bass: Mr. Roberts summed it up best in his last sentence. If it sounds good, it is good... Nice link BTW; thanks!
I accept all your comments at face value.  Whatever shortcomings it has in the way of providing dramatic inspiring flanging, the fact is that flangers cover a lot of ground, much of which isn't terribly different from what a chorus does - just shifted over a bit - and it can do that part just fine.  Admittedly, you wouldn't marry someone just because they know how to dry dishes, switch the clothes over from the washer to the dryer, and bring the garbage out to the curb.  But you do have to accept that the banal tasks are an important part of what makes relationships work, and in this instance the BF-2 handles the banal tasks admirably.  So, while I eagerly await Tomas' explorations for how to bring out the sultry in this build, I'm fine with what's there....for now.
Title: Re: EM3207 (v1.1) - MN3207 based EHX Electric Mistress (9V) clone
Post by: oldschoolanalog on July 11, 2011, 10:45:01 AM
I agree w/you Mark. I just don't feel it's justified to recreate (or thereabouts/a bit "better") the sound of something that can be bought in a pawnshop for ~$30 (US). Less than the cost of parts for doing a DIY flanger. And a heck of alot less time (unless one values their time as zero).
Old saying: "If you are wasting time, you are wasting money. If you are wasting money, you are wasting my time."
Just having a bit of fun also. :D ;)
Title: Re: EM3207 (v1.1) - MN3207 based EHX Electric Mistress (9V) clone
Post by: Thomeeque on July 11, 2011, 03:00:56 PM
John Roberts, who designed many BBD circuits in the 1970s,  offered some suggestions in this post:  http://www.gearslutz.com/board/6693261-post27.html

 Definitely interesting post, thanks, I'll probably read whole thread.

 But when talks about possibility to improve linearity by more sophisticated treatment of BBD outputs (e.g. by using buffer), he probably does not mean straightening of the GAIN-fCLOCK characteristic. It's IMO about lower distortion of passing signal.

"..The MN3101/MN3102 clock chips are nice to use to drive any BBD as they have substantial drive ability compared to the more typical CD4013B approach.."

 Hmm, I wonder how this is meant. When I briefly looked into MN3101/MN3102 specs, it does not look they would even think about frequencies higher than 1MHz..

"I would have liked to use the 4049 inverters set up as two groups of
three paralleled inverters - but the 4047 is not able to drive the
combined gate input capacitance very well... so the technique shown has
been used as a compromise to preserve good rise/fall times."

 Oh, so that's why.. Would 4013's outputs behave same as 4047's (be not able to drive 3 parallel gate inputs capacitance very well), did somebody already try? According to specs both 4047 and 4013 outputs are buffered (I'm kinda surprised, that 3 parallel gate inputs can give hard times to buffered output actually.. but I have very limited knowledge about gates).

 Google returns lot of hits when searching for "clock buffer", like this one: Inexpensive High-Speed Amplifiers Make Flexible Clock Buffers (http://www.analog.com/library/analogdialogue/archives/42-05/clock_buffer.html), but I'm not sure I want to go that deep.. we'll see, first (when I'm back from vacation) I'll measure EM3207's full GAIN-fCLOCK characteristic and maybe try 2x3 buffer yet.

 
Now the BOSS BF1 (Big Blue). There's a nice (guitar) flanger!

 I did not know BF1, impressive monster :icon_mrgreen:

 Cheers, T.
Title: Re: EM3207 (v1.1) - MN3207 based EHX Electric Mistress (9V) clone
Post by: Eduard_Solderingironhands on August 04, 2011, 05:39:20 PM
Hi,

although new here, I'm building DIY stompboxes for more than 20 years. I planned to build an Electric Mistress clone some years ago but forgot to buy the SAD1024. I wanted to finish the project now and - uups- no more SAD1024. I found this thread and the MN3207 looks like a promising alternate.
My question is, if the clock is the sole problem, why not use a microcontroller? These are cheap (at least as cheap as the parts for the LFO if you don't consider the programmer) and run up to 16 MHz, so a clock below 2 MHz should be no challenge. I can offer to design a layout and write the C-code for such a application if you give me the specs. Interested?

Best wishes

Ralf
Title: Re: EM3207 (v1.1) - MN3207 based EHX Electric Mistress (9V) clone
Post by: oldschoolanalog on August 04, 2011, 06:44:13 PM
@Ralf: Check out the MN3007 EM here. Tried & verified. Lots of successful builds and documentation as well.
Title: Re: EM3207 (v1.1) - MN3207 based EHX Electric Mistress (9V) clone
Post by: Thomeeque on August 05, 2011, 05:49:07 AM
Hi,

although new here, I'm building DIY stompboxes for more than 20 years. I planned to build an Electric Mistress clone some years ago but forgot to buy the SAD1024. I wanted to finish the project now and - uups- no more SAD1024. I found this thread and the MN3207 looks like a promising alternate.
My question is, if the clock is the sole problem, why not use a microcontroller? These are cheap (at least as cheap as the parts for the LFO if you don't consider the programmer) and run up to 16 MHz, so a clock below 2 MHz should be no challenge. I can offer to design a layout and write the C-code for such a application if you give me the specs. Interested?

Best wishes

Ralf

 Hi Ralf, welcome! I'm definitely interested, but little sceptical too. Is there a way how to generate clock sweeping from 58 to 2560kHz fluently enough to not make audible "steps" in the sweep? Sweep rate is set usually very slow (seconds), you know..

 If yes, specification is relatively simple:

 Virtual VCO must follow this characteristic:

 (http://thmq.mysteria.cz/em3207/thumb/DEM15V_clock_sweep.gif)

 with frequency doubled.

 Virtual LFO (would you implement LFO part as well? It would IMO make sense) must generate triangles with VMIN = 1.26V and VMAX = ?? (minimal range)* to 10.31V (maximal range). Volts are here of course virtual as well, it's just to make connection with characteristic above.

 Mathematically it's easier to convert frequency to period (as you can see on the "delay" characteristic, period-VCTRL characteristic is practically linear), then can be VCO and LFO definition merged into one simple picture:

 (http://thmq.mysteria.cz/em3207/build/Deluxe_EM3207_optimal_clock.gif)

 Does it make sense? :) I can give you more details, but this should be enough for initial thoughts, I'd say..

 T.

* I'm not sure about this value for minimal range, wild guess is cca 2.5V, I can measure it later (but you could go from VMIN to make RANGE control more versatile then original EMs have).
Title: Re: EM3207 (v1.1) - MN3207 based EHX Electric Mistress (9V) clone
Post by: Thomeeque on August 05, 2011, 06:03:53 AM
@Ralf: Check out the MN3007 EM here. Tried & verified. Lots of successful builds and documentation as well.

 Just small note here:

 If you like 9V EM with MN3007 retrofit, you should like original EM3207 v1.1 (without mods I'm working on now) as well - it should be practically same thing.

 Actually, if somebody would care to make some small demo of 9V EM with MN3007 retrofit, it would be just brilliant!! :)

 Cheers, T.
Title: Re: EM3207 (v1.1) - MN3207 based EHX Electric Mistress (9V) clone
Post by: davidefender on August 05, 2011, 10:45:40 AM
I worked a lot with uC, most with ATmega.. my opinion is that the LFO can be generated not exactly as needed. If you have to reach that freq, it's quite impossible to generate triangle waves (due to the relative slow frequency of the PWM), but you can *easily* get a square wave from 0 to V+ with that specification (LFO speed and clock speed)...  ;D
Title: Re: EM3207 (v1.1) - MN3207 based EHX Electric Mistress (9V) clone
Post by: Thomeeque on August 05, 2011, 11:07:12 AM
I worked a lot with uC, most with ATmega.. my opinion is that the LFO can be generated not exactly as needed. If you have to reach that freq, it's quite impossible to generate triangle waves (due to the relative slow frequency of the PWM), but you can *easily* get a square wave from 0 to V+ with that specification (LFO speed and clock speed)...  ;D

 Primary idea is to replace Clock VCO (LM311+4013) by uC, we want squares at the outputs. Triangles are how should be clock period (1/fCLOCK) swept. Idea to replace both LFO+VCO by uC is secondary (because to me it seems that it would be maybe even easier to do it this way than to try to combine analog LFO and uC VCO).

 T.
Title: Re: EM3207 (v1.1) - MN3207 based EHX Electric Mistress (9V) clone
Post by: davidefender on August 05, 2011, 01:02:33 PM
ok.. so, let's recap:

we need a square wave with a frequency between 60KHz and RANGE (max 2560KHz), right? let's call this signal CLOCK
we also need another signal, LFO that sets the CLOCK frequency change speed, so if the LFO is 1Hz, the CLOCK will pass from 60KHz to RANGE in 1 second, right?

What is the LFO frequency sweep requirement?

..ok so, refering to this datasheet: http://www.atmel.com/dyn/resources/prod_documents/doc8025.pdf  at the beginning of page 99
we can use Timer/Countero as the CLOCK source this way:
The frequency of the waveform generated by this Timer is: Fio / (2 * N * (1 + VALUE))
Fio -> 16MHz (the uC crystal)
we choose a prescaler (N) of 1
VALUE is a 8-bit register, so we choose a min of 2 and a max of 133 for the VALUE parameter... this is not a great solution because we have too few values (only 130), I wonder if there's a smarter solution..
Title: Re: EM3207 (v1.1) - MN3207 based EHX Electric Mistress (9V) clone
Post by: 12Bass on August 05, 2011, 01:40:13 PM
The LFO modulates (sweeps) the BBD clock with a range somewhere between 0.3 Hz and 10 Hz.  Many claim that a hypertriangular LFO waveform sounds the most natural for flanging.
Title: Re: EM3207 (v1.1) - MN3207 based EHX Electric Mistress (9V) clone
Post by: Thomeeque on August 05, 2011, 02:25:46 PM
we need a square wave with a frequency between 60KHz and RANGE (max 2560KHz), right?

 we need a square wave with a frequency between RANGE (min. 60KHz) and 2560KHz

let's call this signal CLOCK

 OK

we also need another signal, LFO that sets the CLOCK frequency change speed, so if the LFO is 1Hz, the CLOCK will pass from 60KHz to RANGE in 1 second, right?

 CLOCK will pass from RANGE to 2560KHz and back in 1 second

What is the LFO frequency sweep requirement?

 cca 0.04Hz (25sec) to 10Hz

The frequency of the waveform generated by this Timer is: Fio / (2 * N * (1 + VALUE))
Fio -> 16MHz (the uC crystal)
we choose a prescaler (N) of 1
VALUE is a 8-bit register, so we choose a min of 2 {~2667kHz} and a max of 133 {59.7kHz} for the VALUE parameter... this is not a great solution because we have too few values (only 130), I wonder if there's a smarter solution..

 Yes, exactly, it would definitely make audible "steps" at slow rates :(

 T.
Title: Re: EM3207 (v1.1) - MN3207 based EHX Electric Mistress (9V) clone
Post by: 12Bass on August 05, 2011, 02:33:57 PM
Ooops.... missed a decimal place there....   :icon_redface:

As to the LFO, smoothness is a necessity for natural-sounding flanging.  Step flanging might be interesting, however....
Title: Re: EM3207 (v1.1) - MN3207 based EHX Electric Mistress (9V) clone
Post by: Mark Hammer on August 05, 2011, 02:44:05 PM
The LFO modulates (sweeps) the BBD clock with a range somewhere between 0.3 Hz and 10 Hz.  Many claim that a hypertriangular LFO waveform sounds the most natural for flanging.
It sounds better for slow speeds, where the feel for how the notches move through the low end of the spectrum is important.  But once you get up above 1hz, where relatively little time is spent at the low end of the sweep anyway, it probably makes no difference, and probably even sounds worse for speeds above 2hz or so, where the sudden upward sweep can sound jarring, as if there is some sort of 10% LFO duty cycle in effect.

All things in context, eh?

The Line 6 Liqui-Flange has stepped flanging, much like hooking up a flanger clock generator to a S&H rather than an LFO, and it sounds very nice.  With a bit of regeneration, it's pretty much like a slightly different Maestro S&H.  Sadly, Line 6 elected not to include such a patch in the M5/M9/M13 series.
Title: Re: EM3207 (v1.1) - MN3207 based EHX Electric Mistress (9V) clone
Post by: Thomeeque on August 05, 2011, 02:50:18 PM
 Many claim that a hypertriangular LFO waveform sounds the most natural for flanging.

 Many claim that a hypertriangular clock frequency sweep sounds the most natural for flanging.

 Beauty of  EMs clock VCO is that input voltage controls period (T) (not frequency) in linear fashion, so linear triangles at the input cause linear period sweep, which means that frequency sweep is hypertriangular (f=1/T).

 Hypertriangular LFO signal would lead to hyper-hyper-triangular frequency sweep in case of EM :)

 T.
Title: Re: EM3207 (v1.1) - MN3207 based EHX Electric Mistress (9V) clone
Post by: Thomeeque on August 05, 2011, 03:03:19 PM
The Line 6 Liqui-Flange has stepped flanging, much like hooking up a flanger clock generator to a S&H rather than an LFO, and it sounds very nice.

 My emulator (http://thmq.mysteria.cz/digital_mistress/index.htm) allows random steps, that sounds interesting too :)

 So steps and random steps could actually make nice bonus features, but we still need smooth sweep available..

 T.
Title: Re: EM3207 (v1.1) - MN3207 based EHX Electric Mistress (9V) clone
Post by: Mark Hammer on August 05, 2011, 04:12:53 PM
 Many claim that a hypertriangular LFO waveform sounds the most natural for flanging.

 Many claim that a hypertriangular clock frequency sweep sounds the most natural for flanging.

 Beauty of  EMs clock VCO is that input voltage controls period (T) (not frequency) in linear fashion, so linear triangles at the input cause linear period sweep, which means that frequency sweep is hypertriangular (f=1/T).

 Hypertriangular LFO signal would lead to hyper-hyper-triangular frequency sweep in case of EM :)

 T.
Hypertriangular works for anything where there is a slow sweep.  That's why we don't use it for chorus or tremolo.  Thomas Henry had a "Smooth phaser" project in Electronic Musician years ago, that used a hypertriangular LFO.  It used an SSM2040 for the 4 OTA-based phase-shift stages, but you don't need to use that..
Title: Re: EM3207 (v1.1) - MN3207 based EHX Electric Mistress (9V) clone
Post by: Eduard_Solderingironhands on August 05, 2011, 06:00:14 PM
Hello,

My (half-baked) idea was to replace the complete LFO + VCO part (4013 / 339) by a microcontroller. The only input would be the voltage from a pot to get the user input for desired sweep rate, using the build in A/D converter. The sweep setting could have a resolution of about 250 - 500 steps, because we can not use precision A/D conversion (this would require to stop the timer for at least 8 ticks while converting which could cause glitches).
I thought of using two timer with a fixed sampling rate. One timer with a relatively low sampling frequency performing a mathematical function which simulates the LFO and does the A/D conversion. The second timer has a very high sampling frequency. The high sampling rate timer just increments a counter. The LFO-function calculates the actual duration of the pulse and the according number of high sampling rate events. If the counter reaches the limit the output is toggled and the timer will be reset.

Best wishes

Ralf





Title: Re: EM3207 (v1.1) - MN3207 based EHX Electric Mistress (9V) clone
Post by: GodSaveMetal on August 05, 2011, 06:02:08 PM
@Ralf: Check out the MN3007 EM here. Tried & verified. Lots of successful builds and documentation as well.

 Just small note here:

 If you like 9V EM with MN3007 retrofit, you should like original EM3207 v1.1 (without mods I'm working on now) as well - it should be practically same thing.

 Actually, if somebody would care to make some small demo of 9V EM with MN3007 retrofit, it would be just brilliant!! :)

 Cheers, T.

The circuit of your proposal is very small!! I made the Jorge's pedals and is enormous; please man how I adaptate the MN3007 for the PCB of yours???? the 3207 are fails and only the 3007 are goods in PERÚ please I want to do that!!!
Title: Re: EM3207 (v1.1) - MN3207 based EHX Electric Mistress (9V) clone
Post by: ORK on August 05, 2011, 06:11:01 PM
While being at it: don`t forget a tap-tempo option!
Title: Re: EM3207 (v1.1) - MN3207 based EHX Electric Mistress (9V) clone
Post by: Thomeeque on August 05, 2011, 06:12:10 PM
Hypertriangular works for anything where there is a slow sweep.  That's why we don't use it for chorus or tremolo.  Thomas Henry had a "Smooth phaser" project in Electronic Musician years ago, that used a hypertriangular LFO.  It used an SSM2040 for the 4 OTA-based phase-shift stages, but you don't need to use that..

 My point is that EMs sweep already *is* hypertriangular with triangular LFO signal, you don't want to make it more hypertriangular (by making LFO signal hypertriangular).

 Here's a snippet from Hyperflange.PDF, where reason for hypertriangularity for flanger is explained:

 (http://thmq.mysteria.cz/em3207/build/Hyperflange.PDF_snippet.gif)

 Btw. A/AD flanger uses apparently same 1/x principle.

That's why we don't use it for chorus or tremolo.

 Actually, Boss CE-2 clock VCO seems to be hypertriangular too (see here (http://www.diystompboxes.com/smfforum/index.php?topic=89044.0)) - it's just not that obvious, because fMAX/fMIN ratio is much smaller..

 I would say that it's not about not using hypertriangularity for faster sweeps (it IMO makes sense everywhere where frequency is swept, no matter how fast), you just use much smaller fMAX/fMIN ratios (~depth) (and maybe sinus instead of triangles) with faster sweeps.

 Tremolo sweeps volume - it is IMO different ballpark, but actually hypertriangularity could make sense here too.. but "naturally sounding" tremolo is maybe too abstract term..

 T.
Title: Re: EM3207 (v1.1) - MN3207 based EHX Electric Mistress (9V) clone
Post by: Thomeeque on August 05, 2011, 06:37:28 PM
The circuit of your proposal is very small!! I made the Jorge's pedals and is enormous; please man how I adaptate the MN3007 for the PCB of yours???? the 3207 are fails and only the 3007 are goods in PERÚ please I want to do that!!!

 I'll look at it tomorrow.. T.
Title: Re: EM3207 (v1.1) - MN3207 based EHX Electric Mistress (9V) clone
Post by: GodSaveMetal on August 05, 2011, 06:39:03 PM
The circuit of your proposal is very small!! I made the Jorge's pedals and is enormous; please man how I adaptate the MN3007 for the PCB of yours???? the 3207 are fails and only the 3007 are goods in PERÚ please I want to do that!!!

 I'll look at it tomorrow.. T.

Great man thanks for your work in this incredible pedal!!!!
Title: Re: EM3207 (v1.1) - MN3207 based EHX Electric Mistress (9V) clone
Post by: davidefender on August 06, 2011, 03:07:07 AM
The second timer has a very high sampling frequency. The high sampling rate timer just increments a counter. The LFO-function calculates the actual duration of the pulse and the according number of high sampling rate events.

The A/D is not a problem, the ATMEGA has built-in 10-bit converter: 1024 steps are enough. The problem remains the "very high sampling frequency", as you can see from my post, a 16MHz crystal is not enough to reach that frequency values. The problem here is not that we cannot produce such signal, but that the uC is too slow to produce a "continous" sweep between 60k and 2M...

For a great result we should have something like a 100MHz or 1GHz oscillator!!  :icon_eek:
Title: Re: EM3207 (v1.1) - MN3207 based EHX Electric Mistress (9V) clone
Post by: sugonidamaso on August 06, 2011, 05:24:08 AM
hi T!just saw this subj/thread.i mean wow!should i say smaller/easier version of your em1022.i made the earlier version of mistress retrofit(great topic :icon_razz:).my problem is that its too big.haven't got a nice enclosure to it (having a 14x20pedalboard).majority of my pedals are in a 1590b enclosure.so compact.anyways,my question is that 2n5087 is not available in my area.i just substitute it by 2n4250. is there any difference?newbie here :icon_redface: :icon_redface: :icon_redface: :icon_redface:.thank you!more power!
Title: Re: EM3207 (v1.1) - MN3207 based EHX Electric Mistress (9V) clone
Post by: Thomeeque on August 06, 2011, 07:43:28 AM
hi T!just saw this subj/thread.i mean wow!should i say smaller/easier version of your em1022.i made the earlier version of mistress retrofit(great topic :icon_razz:).my problem is that its too big.haven't got a nice enclosure to it (having a 14x20pedalboard).majority of my pedals are in a 1590b enclosure.so compact.anyways,my question is that 2n5087 is not available in my area.i just substitute it by 2n4250. is there any difference?newbie here :icon_redface: :icon_redface: :icon_redface: :icon_redface:.thank you!more power!

 You mean to substitute 2N5087 by 2N4250 in the clock circuitry (Q2 in EM3207 v1.1), right? I have substituted it by different PNP in my "standalone replica of the clock" (http://www.diystompboxes.com/smfforum/index.php?topic=91981.msg792520#msg792520) at the beginning and it worked, but when I have put 2N5087 there later I have got quite different readings. I did not try to findout why. So I cannot tell honestly. You definitely can try to use it and I'm 99% sure that it will work, but you may (or may not) get little different frequency range and sweep.

 Good luck, T.
Title: Re: EM3207 (v1.1) - MN3207 based EHX Electric Mistress (9V) clone
Post by: sugonidamaso on August 06, 2011, 08:50:45 AM
Thank you so much T!looking forward to build this one.will transform the old EM retrofit to this one. ;D ;D ;D ;D ;D
Title: Re: EM3207 (v1.1) - MN3207 based EHX Electric Mistress (9V) clone
Post by: Eduard_Solderingironhands on August 06, 2011, 05:02:05 PM
Hello,

o.k. I think it is not possible to drive a MN3207 directly by an Atmega. A maximum frequency of 2.5 MHz would require a timer event at 5 MHz. Even if overclocking the Atmega this is too sportive.

Best wishes

Ralf
Title: Re: EM3207 (v1.1) - MN3207 based EHX Electric Mistress (9V) clone
Post by: Mark Hammer on August 06, 2011, 05:25:49 PM
The second timer has a very high sampling frequency. The high sampling rate timer just increments a counter. The LFO-function calculates the actual duration of the pulse and the according number of high sampling rate events.

The A/D is not a problem, the ATMEGA has built-in 10-bit converter: 1024 steps are enough. The problem remains the "very high sampling frequency", as you can see from my post, a 16MHz crystal is not enough to reach that frequency values. The problem here is not that we cannot produce such signal, but that the uC is too slow to produce a "continous" sweep between 60k and 2M...

For a great result we should have something like a 100MHz or 1GHz oscillator!!  :icon_eek:
But one of these devices would still be perfect for generating an "optimized" LFO output that adjusted waveform and amplitude with speed.  Imagine an LFO that got more hypertriangular and had greater sweep width the slower the speed: a 2-knob flanger (speed and regeneration).
Title: Re: EM3207 (v1.1) - MN3207 based EHX Electric Mistress (9V) clone
Post by: Thomeeque on August 07, 2011, 08:24:47 AM
The circuit of your proposal is very small!! I made the Jorge's pedals and is enormous; please man how I adaptate the MN3007 for the PCB of yours???? the 3207 are fails and only the 3007 are goods in PERÚ please I want to do that!!!

 EM3007 (v1.1)

 (http://thmq.mysteria.cz/em3207/big/EM3007_v1.1_schematic_1280.gif)
 ( don't print this schematic, following link contains high-quality print version )

 EM3007_v1.1_schema_1200DPI.png (http://thmq.mysteria.cz/em3207/build/EM3007_v1.1/EM3007_v1.1_schema_1200DPI.png)
 EM3007_v1.1_PCB_1200DPI.png (http://thmq.mysteria.cz/em3207/build/EM3007_v1.1/EM3007_v1.1_PCB_1200DPI.png)
 EM3007_v1.1_PCB_mirror_1200DPI.png (http://thmq.mysteria.cz/em3207/build/EM3007_v1.1/EM3007_v1.1_PCB_mirror_1200DPI.png)
 EM3007_v1.1_jumpers_1200DPI.png (http://thmq.mysteria.cz/em3207/build/EM3007_v1.1/EM3007_v1.1_jumpers_1200DPI.png)
 EM3007_v1.1_names_1200DPI.png (http://thmq.mysteria.cz/em3207/build/EM3007_v1.1/EM3007_v1.1_names_1200DPI.png)
 EM3007_v1.1_values_1200DPI.png (http://thmq.mysteria.cz/em3207/build/EM3007_v1.1/EM3007_v1.1_values_1200DPI.png)

 Build instructions (including shopping list* and wirepad positions) remain same.

 * Two exceptions:
 1x MN3207 MN3007 (IC2)
 1x Zenner 10V 15V/5W (D3)

 T.
Title: Re: EM3207 (v1.1) - MN3207 based EHX Electric Mistress (9V) clone
Post by: sugonidamaso on August 07, 2011, 08:39:11 AM
Hi T! How does it differ from the 3207?Thanks!
Title: Re: EM3207 (v1.1) - MN3207 based EHX Electric Mistress (9V) clone
Post by: Thomeeque on August 07, 2011, 10:35:05 AM
Hi T! How does it differ from the 3207?Thanks!

 It is EM3207 v1.1 adopted for use of MN3007 BBD chip, all diffs are listed in the small table at top of the schematic, there are no any other changes. T.

Title: Re: EM3207 (v1.1) - MN3207 based EHX Electric Mistress (9V) clone
Post by: GodSaveMetal on August 07, 2011, 12:13:19 PM
The circuit of your proposal is very small!! I made the Jorge's pedals and is enormous; please man how I adaptate the MN3007 for the PCB of yours???? the 3207 are fails and only the 3007 are goods in PERÚ please I want to do that!!!

 EM3007 (v1.1)

 (http://thmq.mysteria.cz/em3207/big/EM3007_v1.1_schematic_1280.gif)
 ( don't print this schematic, following link contains high-quality print version )

 EM3007_v1.1_schema_1200DPI.png (http://thmq.mysteria.cz/em3207/build/EM3007_v1.1/EM3007_v1.1_schema_1200DPI.png)
 EM3007_v1.1_PCB_1200DPI.png (http://thmq.mysteria.cz/em3207/build/EM3007_v1.1/EM3007_v1.1_PCB_1200DPI.png)
 EM3007_v1.1_PCB_mirror_1200DPI.png (http://thmq.mysteria.cz/em3207/build/EM3007_v1.1/EM3007_v1.1_PCB_mirror_1200DPI.png)
 EM3007_v1.1_jumpers_1200DPI.png (http://thmq.mysteria.cz/em3207/build/EM3007_v1.1/EM3007_v1.1_jumpers_1200DPI.png)
 EM3007_v1.1_names_1200DPI.png (http://thmq.mysteria.cz/em3207/build/EM3007_v1.1/EM3007_v1.1_names_1200DPI.png)
 EM3007_v1.1_values_1200DPI.png (http://thmq.mysteria.cz/em3207/build/EM3007_v1.1/EM3007_v1.1_values_1200DPI.png)

 Build instructions (including shopping list* and wirepad positions) remain same.

 * Two exceptions:
 1x MN3207 MN3007 (IC2)
 1x Zenner 10V 15V/5W (D3)

 T.

Mr.Thomeeque your amazing!!! you are great!!! thank THANKS for your work!!!!!!!!!! muchísimas gracias!!!
Title: Re: EM3207 (v1.1) - MN3207 based EHX Electric Mistress (9V) clone
Post by: Thomeeque on August 07, 2011, 12:20:08 PM
 You are welcome, Roberto :) Good luck with your build! T.
Title: Re: EM3207 (v1.1) - MN3207 based EHX Electric Mistress (9V) clone
Post by: 12Bass on August 07, 2011, 02:48:45 PM
Thanks Thomeeque!  May have to build one of these with the MN3007s I have.  Ever built up an A/DA clone?
Title: Re: EM3207 (v1.1) - MN3207 based EHX Electric Mistress (9V) clone
Post by: mth5044 on August 07, 2011, 11:36:14 PM
Now do a polychorus  :P

Great work! I hope one day to build this! Thanks!
Title: Re: EM3207 (v1.1) - MN3207 based EHX Electric Mistress (9V) clone
Post by: Thomeeque on August 08, 2011, 05:30:41 AM
Thanks Thomeeque!  May have to build one of these with the MN3007s I have.

 Good luck to you too then :)

 It's interesting, I have choosen MN3207 as the shortest BBD still in production (?), but it looks like there's still enough MN3007s :)

Ever built up an A/DA clone?

 Nope, with EM it was love at first sight and I don't want any other!! :) But I may try it's LFO/VCO, could be interesting..

Now do a polychorus  :P

 Sure, sure.. :icon_mrgreen:

Great work! I hope one day to build this! Thanks!

 Me too ;)

 Cheers, T.
Title: Re: EM3207 (v1.1) - MN3207 based EHX Electric Mistress (9V) clone
Post by: head_spaz on August 08, 2011, 11:22:24 AM
Are pcbs still available for this project?
Title: Re: EM3207 (v1.1) - MN3207 based EHX Electric Mistress (9V) clone
Post by: 12Bass on August 08, 2011, 05:50:05 PM
It's interesting, I have choosen MN3207 as the shortest BBD still in production (?), but it looks like there's still enough MN3007s :)

I've found lack of headroom to be a bit of an issue with my SAD1024 A/DA clone, so that is a big factor in wanting to use the higher voltage MN3007 instead of the MN3207.  Usually I play bass, so that application might require a little more headroom than guitar.  Didn't have too much trouble sourcing MN3007s.  Plus, I've already got an 18 V supply for my A/DA.  

Nope, with EM it was love at first sight and I don't want any other!! :) But I may try it's LFO/VCO, could be interesting.

Please let us know if you do.  I'm curious to know how it might impact the sound of the flanger.  The different LFO is one reason why I'm curious to build an EM, that and because the signal path is somewhat more straightforward.
Title: Re: EM3207 (v1.1) - MN3207 based EHX Electric Mistress (9V) clone
Post by: oldschoolanalog on August 08, 2011, 09:58:16 PM
Nope, with EM it was love at first sight and I don't want any other!! :)...
In the realm of flanger "relationships"; infidelity is not only a good thing; but an absolute necessity! ;)
Speaking on a (slightly) unrelated note...
Tomas; is that totally cool singer in your band single? (Say yes and I'm on my way to Prague!) ;D
The Dark Side?, Cookies? I'll bring the beverages!


Title: Re: EM3207 (v1.1) - MN3207 based EHX Electric Mistress (9V) clone
Post by: Thomeeque on August 09, 2011, 09:55:05 AM
Are pcbs still available for this project?

 I'm sorry, but they never were :( you have to etch yours or order it from some PCB pro (others may give you hint, where are you from?)

I've found lack of headroom to be a bit of an issue with my SAD1024 A/DA clone, so that is a big factor in wanting to use the higher voltage MN3007 instead of the MN3207.  Usually I play bass, so that application might require a little more headroom than guitar.  Didn't have too much trouble sourcing MN3007s.  Plus, I've already got an 18 V supply for my A/DA.  

 I see..

Nope, with EM it was love at first sight and I don't want any other!! :) But I may try it's LFO/VCO, could be interesting.

Please let us know if you do.  I'm curious to know how it might impact the sound of the flanger.  The different LFO is one reason why I'm curious to build an EM, that and because the signal path is somewhat more straightforward.

 Yep, signal path in A/AD flanger is a tough puzzle :)

Nope, with EM it was love at first sight and I don't want any other!! :)...
In the realm of flanger "relationships"; infidelity is not only a good thing; but an absolute necessity! ;)
Speaking on a (slightly) unrelated note...
Tomas; is that totally cool singer in your band single? (Say yes and I'm on my way to Prague!) ;D

 She was.. until the first night of our first road trip with her on-board .. then our totally cool bass player took his chance and scored ;D

 But you can come to Prague to see me :icon_mrgreen:

The Dark Side?, Cookies? I'll bring the beverages!

 Yep, beverages were involved, lot of them ;)

 T.
Title: Re: EM3207 (v1.1) - MN3207 based EHX Electric Mistress (9V) clone
Post by: Eduard_Solderingironhands on August 09, 2011, 04:40:39 PM
Hello Thomas,

today I talked to colleague of mine who is expert for high frequency and asked him for some hints why the VCO doesn't operate up to 2.5 MHz. He asked me to build it in hardware and offered to make some measurements. The parts are ordered.
Until then he suggested (shot from the hip) to try a LM6511 or LM319 instead of the LM311 or to put a buffer between the LM311 and the 4013.

Best wishes

Ralf
Title: Re: EM3207 (v1.1) - MN3207 based EHX Electric Mistress (9V) clone
Post by: Thomeeque on August 22, 2011, 05:30:45 PM
Hello Thomas,

today I talked to colleague of mine who is expert for high frequency and asked him for some hints why the VCO doesn't operate up to 2.5 MHz. He asked me to build it in hardware and offered to make some measurements. The parts are ordered.
Until then he suggested (shot from the hip) to try a LM6511 or LM319 instead of the LM311 or to put a buffer between the LM311 and the 4013.

Best wishes

Ralf

 Hello Ralf,

 that's cool, thanks! Sorry for the late answer, I have too much other duties lately. Just please note that it's not only about getting higher frequency, it's about clarity of V/f characteristics too. Clarity is actually more important - once sweep looses it's fluency, it's unpleasantly audible and therefor worthless (it's then better to stay at lower frequencies in the fluent area). Just to remind, goal is simple - VCO must follow this characteristic:

 (http://thmq.mysteria.cz/em3207/thumb/DEM15V_clock_sweep.gif)

 with frequency doubled.

 Using common LM311N and after some tweaking* I have got this characteristic (measured on my "clock replica" for three different clock capacitor values):

 (http://thmq.mysteria.cz/em3207/build/EM3x07_clock_on_CC_half.gif) (http://thmq.mysteria.cz/em3207/build/EM3x07_clock_on_CC.gif)
 (click the pic for hi-res)

 As you can see, use of smaller clock capacitor moves highest frequency just by little (at the low end it's perfectly proportional), there is some sort of ceiling around 2MHz (actually, when you completely remove clock capacitor, it still ticks and maximum is IIRC 2.2MHz). Plus with small value the characteristic gets (audibly) "slowed-down" and crippled (you can see that "bump" around 1500kHz on the red curve)**. Twiddling with other parts has similar effect, EM clock using common LM311N seems to have this limit.

 If your friend would find the way how to move this ceiling to at least 2.5MHz either by modifying current circuit around LM311N or by using other commonly available comparator, it could be definitely interesting.

 On the other hand, 12BASS is right, for "normal" flange use we don't need it that much. It was more challenge for me than the real need :)

 Cheers, T.

* To extend clock's range it is necessary to make LM311's output stronger, unmodified it is not able to drive 4013's input properly above 1300kHz. Trick is to make R34 smaller, LM311's output is open collector (minimal value seems to be 1k, below this value it starts to fail again for some other reason - R34 = 1k was used for the characteristic above).

** So actually to get the biggest possible range and the most pleasing sweep it's best to stay with 47pF and move VCTRL sweep range ("stock" range starts at 1.15V), which is relatively simple.
Title: Re: EM3207 (v1.1) - MN3207 based EHX Electric Mistress (9V) clone
Post by: Thomeeque on August 22, 2011, 06:28:46 PM
 I have got few questions via PM (some of them already second time), I answer them here:

Do you know where, in Europe, I could get the 10V/5W Zener diode [D3] or can it be exchanged for something else? I haven't seen it anywhere...

 D3 is there for the overvoltage (10V is maximal VCC for MN3207) and polarity protection. It is not necessary for function of the effect, you don't need to have it there at all, but I don't recommend to go without D3. If you cannot get 10V/5W Zener, try to get 1W or use at least normal rectifier diode (e.g. 1N4007) there for the polarity protection (if you use only 9V PSU for all your stompboxes, you should not overvoltage it). But 10V/5W zener diode should be pretty common part, shops around me sell e.g. 1N5347B.

 I also have a question about the [100nF DC blocking] caps that go underneath the IC's, which pins are you talking about (V+)?

 I'm talking about supply pins - GND and VCC (VDD):

 IC1 (4558) - pins 4 and 8
 IC2 (MN3207) - pins 1 and 5
 IC3 (LM324) - pins 11 and 4
 IC4 (LM311) - pins 4 and 8
 IC5 (4013) - pins 7 and 14
 IC6 (4049) - pins 8 and 1

 Solder as close to the pins as possible. It is an optional step, which should help with potential noise issues. Do it as the last step, when circuit is perfectly working.

 Does it matter if it's the buffered or unbuffered cd4049?

 I'd say it could matter - since 4049 is here used as a clock signals buffer, buffered version makes more sence to me and I always used buffered version. But there may be other opinion, I have not done any deeper research about this matter yet.

 Good luck, T.
Title: Re: EM3207 (v1.1) - MN3207 based EHX Electric Mistress (9V) clone
Post by: asatbluesboy on August 23, 2011, 09:13:27 AM
1) We seriously need a "thanks" button.
2) Love the heart tupperware thing. :D
Title: Re: EM3207 (v1.1) - MN3207 based EHX Electric Mistress (9V) clone
Post by: Thomeeque on August 23, 2011, 11:26:30 AM
1) We seriously need a "thanks" button.

 Never mind, there's no "you're welcome" button either ;)

2) Love the heart tupperware thing. :D

 He he, thanks :) I love it too, it's very useful for bare PCB circuits testing and tuning - shape is not ideal (walls are nowhere totally straight), but I needed it a lot and it was first metal can with acceptable dimensions available.

 Cheers, T.
Title: Re: EM3207 (v1.1) - MN3207 based EHX Electric Mistress (9V) clone
Post by: Eduard_Solderingironhands on August 24, 2011, 02:34:55 PM
Hello Thomas,

unfortunately my colleague is quite busy at the moment, but I did some testing by my own. I built your 3207 version 1.1 and a VCO testbench similar to yours. What I found out up to now:

1. I got a genuine EH Deluxe Electric Mistress "Reissue" with the RD5106. The RD5106 would require double clock frequency similar to the MN3207, but EH kept the SDA clock frequency. The sound of the Reissue is similar to your 3207 version 1.1 except for longer delay and is definetly not worth the money.

2. The EH LFO goes from  1.26 V to 10.31 V @ 16 V for the vintage EM, which equals 8 % to 64 % Vs. The Resissue is 1.4 V to 8.0 V @ 12 V, which equals 12 % to 67 %.
My 3207 version 1.1 goes from 1.1 V to 3.95 V @ 9V which equals 12 % to 44 %. (At least that's what I measured from mine - Can you please confirm these values). In case these values are right you should extend the sweep range by adjusting R21, R22 and R27.

3. The LM311 has a responce time of 200 ns according to the datasheet. I dont`t think you can achieve 2.5 MHz with the LM311. This is my measurement of the LM311 @ 1 MHz:
(http://www.metzgerralf.de/elekt/mistress/LM311.jpg)

4. I tried the LM319. This thing really speeds things up. You can easily let the VCO oscillate faster than 10 MHz. With the LM319 I found out that the maximum frequency of the CD4013s I have is 2.2 MHz. If the frequcency out of the VCO is faster, the CD4013 will get unstable.

5. Unfortunately I could not achieve the desired 2.56 MHz to 58 kHz with the LM319. As the LM319 has a faster responce, we must either increase the capacitor or reduce the charge current to the capacitor by the trimpot. If the capacitor is increased, the responce characteristic will change significantly. If the charging current is reduced the LM319 gets some strange oscillation at cetrtain frequencies. I am not sure yet what causes these oscillation. Here are some pictures.
LM319 @ 1MHz
(http://www.metzgerralf.de/elekt/mistress/LM319.jpg)

LM319 with lower charging current and oscillation:
(http://www.metzgerralf.de/elekt/mistress/LM311_oszi.jpg)

The slowest delays I could achieve without oscillation (Vs = 9V):
[Edit]new diagramm - now no nonsense[/Edit]
(http://www.metzgerralf.de/elekt/mistress/uf.jpg)


I would like to try the LM6511 next which is faster than the LM311 and slower than the LM319, but the shops I normally buy from don't have this one in stock.

Best wishes

Ralf
Title: Re: EM3207 (v1.1) - MN3207 based EHX Electric Mistress (9V) clone
Post by: Thomeeque on August 25, 2011, 06:22:04 AM
 Wow, amazing work! Thank you, Ralf!

I built your 3207 version 1.1

 Nice, you are probably first one, how do you like it? :)

1. I got a genuine EH Deluxe Electric Mistress "Reissue" with the RD5106. The RD5106 would require double clock frequency similar to the MN3207, but EH kept the SDA clock frequency. The sound of the Reissue is similar to your 3207 version 1.1 except for longer delay and is definetly not worth the money.

 I wonder if they tried do double frequency as we are trying now :)

2. The EH LFO goes from  1.26 V to 10.31 V @ 16 V for the vintage EM, which equals 8 % to 64 % Vs.

 1.26 V to 10.31 V @ 15 V for the vintage EM, which equals 8.4 % to 68.7 % Vs.

 Huge range, I know :)

The Resissue is 1.4 V to 8.0 V @ 12 V, which equals 12 % to 67 %.

 Did you measure it in FLANGE or FILTER-MATRIX mode? F-M mode has extended range over FLANGE mode in the EC1000 reissue (different wiring of MODE switch) - FLANGE mode circuitry is 100% equal with EM3207.

My 3207 version 1.1 goes from 1.1 V to 3.95 V @ 9V which equals 12 % to 44 %. (At least that's what I measured from mine - Can you please confirm these values).

 Mine from 1.13 to 4.35V @ 10V which equals 11.3% to 43.5%, so I can confirm your values.

In case these values are right you should extend the sweep range by adjusting R21, R22 and R27.

 I've been playing with these values :) This is definitely possible way, but you have to be careful to not detune FLANGE vs. F-M ranges. I have found maybe easier (less invasive if you will) way:

 replacing RANGE pot by 250k (it extends top limit of range to almost 90%) and adding properly calculated resistor over C16 forming voltage divider with R30.

 It has it's drawbecks too (divider moves both limits down), but it allows IMO easier tuning of the clock (if you use pot over C16, you can move fluently minimal limit, which is the more interesting limit when hunting for highest possible clock).

 I'll answer to the rest later (now I'm going to lunch and for few LM319s :D), cheers, T.
Title: Re: EM3207 (v1.1) - MN3207 based EHX Electric Mistress (9V) clone
Post by: Eduard_Solderingironhands on August 25, 2011, 02:09:25 PM
Hello Thomas,

Quote
Nice, you are probably first one, how do you like it?
Sorry, but I can't judge yet. I haven't played it much. I soldered it together, looked if it is working and measured the LFO and VCO. I didn't even adjust all trimm pots by now.

The Resissue is 1.4 V to 8.0 V @ 12 V, which equals 12 % to 67 % - in Flange mode.

My colleague guessed the oscillation comes from the 1N4148. He suggested to put a small capacitor from the output of the LM319 to GND to slow down the LM319 a bit. A already tried this but the capacitor makes the limit of the 4013 slower. But as the 4013 is too slow anyway I will try this next:
(http://www.metzgerralf.de/elekt/mistress/idea.jpg)
A 74AC74 instead of the 4013. The problem is that the 74AC74 can be only operated at maximum 7 V. We need a resistor as voltage divider parallel to the capacitor. I am not sure if this resistor will cause unexpected problem for the negative input of the LM319. But we will see.

Best wishes

Ralf
Title: Re: EM3207 (v1.1) - MN3207 based EHX Electric Mistress (9V) clone
Post by: Thomeeque on August 25, 2011, 03:18:07 PM
The Resissue is 1.4 V to 8.0 V @ 12 V, which equals 12 % to 67 % - in Flange mode.

 Hmm, maybe it's not EC1000 or it does not match 100% with schematic I've got.. nevermind, not important..

My colleague guessed the oscillation comes from the 1N4148. He suggested to put a small capacitor from the output of the LM319 to GND to slow down the LM319 a bit. A already tried this but the capacitor makes the limit of the 4013 slower..

 Did you try smaller value for R34 to make comparator output stronger? With Tesla MAB311 and R34=1k I have got to 3MHz at the 4013 output, so maybe 4013 is not bottleneck here..?

 Btw. I've seen those oscillations when emulating the clock in LTSpice - I thought it was caused by some LTSpice approximation or something similar and now I see that it was correct, interesting!

 And another btw.: that R3/R4 divider as supply source for 74AC74 won't work, it's way too weak source..

 Cheers, T.
Title: Re: EM3207 (v1.1) - MN3207 based EHX Electric Mistress (9V) clone
Post by: Eduard_Solderingironhands on August 25, 2011, 04:44:24 PM
Hello Thomas,

reducing R34 to 1k helps to reduce the unwanted oscillations of the LM319 and helps to increase the maximum frequency out of the 4013. With a Schottky diode for D2 instead of the 1N4148 I had 7 MHz at the otuput of the 4013. New speed record ;)

But I could not achieve a lower frequency than 150 kHz. A capacitor between LM319 out and GND doesn't help at all. Changing D2 with different diodes only resulted in higher frequencies, not lower. I am not sure if the LM319 is the right way. I think it is too fast.

Best wishes

Ralf
Title: Re: EM3207 (v1.1) - MN3207 based EHX Electric Mistress (9V) clone
Post by: Thomeeque on August 25, 2011, 05:44:38 PM
Hello Thomas,

reducing R34 to 1k helps to reduce the unwanted oscillations of the LM319 and helps to increase the maximum frequency out of the 4013. With a Schottky diode for D2 instead of the 1N4148 I had 7 MHz at the otuput of the 4013. New speed record ;)

But I could not achieve a lower frequency than 150 kHz. A capacitor between LM319 out and GND doesn't help at all. Changing D2 with different diodes only resulted in higher frequencies, not lower. I am not sure if the LM319 is the right way. I think it is too fast.

Best wishes

Ralf

 I've just started my first experiments with LM319 in my clock replica before a while, I've got very high frequencies at 4013 outs too (around 5MHz with 1N4148), I was not sure if it's not just measuring error (I cannot use my pseudo oscilloscope at these frequencies and I'm not sure how much I can rely on my frequency meter either), so I'm really glad for your results - so even 7MHz, wow! :)

 Comparator should not be "too fast" for this VCO - at least basic principle of this clock - how I understand it - is that constant current source (emitter of Q2) charges C17 until voltage on this capacitor is bigger than control voltage at positive input of comparator, then comparator flops and discharges C17 rapidly via D2, flops back and charging of C17 starts again. Biggest the control voltage is, longer charging takes - so with bigger voltage period grows, frequency decline (and vice versa). It's well visible here (http://thmq.mysteria.cz/em3207/detail.htm?DEM15V_clock_LTC.gif). So even infinitely fast comparator should work here, frequency is not set be it's speed (I'm still talking about basic principle - in reality and especially at high frequencies everything metters as we well know already), it's set by current ("clock trimmer" RT3) and by value of the capacitor.

 So, try to increase value of C17 and lower charging current to get frequencies down, it should be the way..

 T.
Title: Re: EM3207 (v1.1) - MN3207 based EHX Electric Mistress (9V) clone
Post by: Eduard_Solderingironhands on August 27, 2011, 01:44:10 PM
Hello Thomas,

Increasing C17 or lowering the charging current doesn't help. With lower charging currents the LM319 gets unwanted oscillation.
Increasing C17 only alters the u to f function but not the maximum lowest frequency. The LM319 has almost no hysteresis. If the voltage at V- is greater than V+, the ouput will toggle to low and C17 will be discharged over the comparator. But immediately after the output toggels to low and the discharging starts, V- will drop below V+ and the otuput will toggle back to high before C17 is fully discharged.
That is why we probably need a slower comparator or some kind of hysteresis.
With a fast comparator it may be easier to go to 5.12 MHz to 116 kHz and use the second FilpFlop of the 4013 to devide the frequency into half.

Best wishes

Ralf
Title: Re: EM3207 (v1.1) - MN3207 based EHX Electric Mistress (9V) clone
Post by: Thomeeque on August 27, 2011, 05:37:16 PM
 Ralf, you're good! What you say makes perfect sense. I got to admit, that I was little unsure all the time about the phase where the capacitor gets discharged, about what and why happens there exactly, my understanding was too simplified.

 Could we somehow use second half of 319 to slow comparator down?

 Thanks, T.
Title: Re: EM3207 (v1.1) - MN3207 based EHX Electric Mistress (9V) clone
Post by: Valentinych on August 28, 2011, 04:13:36 AM
Hi all!  
Friends, you are giving too much emphasis on VCO LM311 … There are more important conditions MN3x07 management. In datasheet on these chips specified Clock Pulse Waveforms CP1 and CP2:

(http://img220.imageshack.us/img220/8585/mn3007.jpg) (http://imageshack.us/photo/my-images/220/mn3007.jpg/)   (http://img696.imageshack.us/img696/5498/mn3207.jpg) (http://imageshack.us/photo/my-images/696/mn3207.jpg/)
                                MN3007                                                                                MN3207

From the datasheet that the clock cross point (Vx) CP1/CP2 MN3007 for should be based not below 3 volts, and 1.7 volts MN3207 not above GND level.

When generating speed through triggers (4013, etc.), the clock cross point has a level 1/2 Vdd means BBD works not in an optimal mode.
A few years ago, I experimented, and compared the treatment of clocking by using MN3102 and 4013. At high frequencies (above ~ 500 kHz) S/N output 3207 in "trigger" mode was markedly worse than in regular mode. In addition, the output level was less than ~1.5-2 dB.  This is because the principle of BBD.

I recently made new measurements of clocks, MN3207 clearly visible delay fronts phased impulses. The delay time is absolutely does not depend on the frequency. Photo taken on my Takwey DST1202.
Vdd = 9V. CP1 showing in yellow, CP2 shown in blue:

(http://img689.imageshack.us/img689/6830/tekway144.jpg) (http://imageshack.us/photo/my-images/689/tekway144.jpg/)
Waveforms at 53.29 kHz. Delay front 140 ns.

(http://img202.imageshack.us/img202/6004/tekway143.jpg) (http://imageshack.us/photo/my-images/202/tekway143.jpg/)
Waveforms at 172.95 kHz. Delay front 140 ns.

(http://img641.imageshack.us/img641/4930/tekway142.jpg) (http://imageshack.us/photo/my-images/641/tekway142.jpg/)
Waveforms at 495.8 kHz. Delay front 140 ns.

(http://img32.imageshack.us/img32/4515/tekway141.jpg) (http://imageshack.us/photo/my-images/32/tekway141.jpg/)
Waveforms at 1.805 MHz. Delay front 140 ns.


(http://img834.imageshack.us/img834/6946/tekway148.jpg) (http://imageshack.us/photo/my-images/834/tekway148.jpg/)
Waveforms at 53.17 khz. Maximal amplitude of rectangular form.

(http://img850.imageshack.us/img850/996/tekway149.jpg) (http://imageshack.us/photo/my-images/850/tekway149.jpg/)
Waveforms at 318.84 khz. Amplitude and waveform does not change.

(http://img846.imageshack.us/img846/9776/tekway1410.jpg) (http://imageshack.us/photo/my-images/846/tekway1410.jpg/)
Waveforms at 1.015 Mhz. Amplitude and waveform does not change.

(http://img690.imageshack.us/img690/4343/tekway145.jpg) (http://imageshack.us/photo/my-images/690/tekway145.jpg/)
Waveforms at 1.62 Mhz. Amplitude and shape of the wave is beginning to change.

(http://img842.imageshack.us/img842/1766/tekway146.jpg) (http://imageshack.us/photo/my-images/842/tekway146.jpg/)
Waveforms at 2.01 Mhz. Amplitude and shape wave greatly changed. Clearly expressed asymmetry phases.

As the experiments showed my MN3102 quite satisfactorily generates at frequencies up to 2 Mhz, 4 MHz frequency which corresponds to the comparator LM311. The MN3102 generates the necessary delay fronts. However, since the frequency of ~ 1.2 -1.5 MHz pulse form is not symmetric and strongly CPx tamed, and reminds the bell, rather than a rectangle.
Moreover, at such high frequencies MN3102 cannot provide fast charge input capacitance MN3207, which is used in most development flangers.

But if the output MN3102 to fix an additional buffer (4049) as in the diagram by Thomas from the first message, everything is great!
An even better result would be, if the buffer is 4049, and the special dual high-speed MOSFET driver type MIC4424, or similar.  Such drivers I have few years apply in our developments on BBD.  

Good luck to all! Igor (aka Valentinych).

P.S. Sorry for my bad English ...
Title: Re: EM3207 (v1.1) - MN3207 based EHX Electric Mistress (9V) clone
Post by: 12Bass on August 28, 2011, 06:46:10 AM
When generating speed through triggers (4013, etc.), the clock cross point has a level 1/2 Vdd means BBD works not in an optimal mode.
A few years ago, I experimented, and compared the treatment of clocking by using MN3102 and 4013. At high frequencies (above ~ 500 kHz) S/N output 3207 in "trigger" mode was markedly worse than in regular mode. In addition, the output level was less than ~1.5-2 dB.  This is because the principle of BBD.

Informative post, Valentinych!

When you mention signal loss as a "principle of BBD", are you saying that BBDs inherently have lower gain at high clock rates?  This is indicated on the datasheets, IIRC.  Does a rounded clock signal impact the gain, or just the fidelity of the signal?

Would you happen to have any clock waveform traces with a 4049 buffer in place?  I've built an A/DA flanger clone using an SAD1024A with a 4049 buffer in the clock circuit.  It is calibrated for up to 2.6 MHz at the very top (0.2 mS).  From what I understand, the Reticon BBDs have less capacitance at the clock inputs and thus do not round off the clock signal as much as the Panasonic MN devices.  Still, I'd be curious to see what the clock waveform looked like with and without the 4049 buffer in place.

Title: Re: EM3207 (v1.1) - MN3207 based EHX Electric Mistress (9V) clone
Post by: Valentinych on August 28, 2011, 10:01:05 AM
When you mention signal loss as a "principle of BBD", are you saying that BBDs inherently have lower gain at high clock rates?  This is indicated on the datasheets, IIRC.  Does a rounded clock signal impact the gain, or just the fidelity of the signal?
OK. I'll try to prepare a response, and will write later.
Title: Re: EM3207 (v1.1) - MN3207 based EHX Electric Mistress (9V) clone
Post by: Valentinych on August 28, 2011, 11:52:44 AM
Principle of operation BBD is based on moving electric charge consistently from one potential holes in another.
The entire line is split into odd and even levels (cells). All even-numbered (and odd-numbered) cells are connected to input controls, and managed at the same time. Therefore, control signal has two phases – CP1 and CP2. 
When the input signal is chip CP1 high-level you record level input LF-signal in the first cell, and simultaneously charge transfer from the second (fourth, sixth, etc.) of the cell in the third (fifth, seventh, etc.). Signal from the last even cells in this time shall be applied to the output circuits. 
When the input signal is CP2 high-level, shifting charges from all odd-numbered cells (third, fifth, etc.) in the following even-numbered cells (the fourth, sixth, and so on). Signal from the latest odd cell at this time is output circuits.
Time CP1+CP2 determines the period of the clock frequency.

But for transfer charge from one cell to another requires some time (Tmin), then the signal duration CPx must be greater than the minimum time Tmin. Therefore, the maximum clock speed control signals are defined as Fclock <= 1/(2 * Tmin). 
For the full transfer charges in real chips still required some time Tdead, which shares the signals CP1 and CP2. It is well visible on my photo above. 
If Fclock will have more maximum, or Tdead less than the required time, happen not full migration charges from cell to cell, or partial mixing charges of adjacent cells. 
These causes reduced signal level output BBD on high Fclock’s, and the deterioration of the signal/noise ratio.

Hopefully, someone will understand what I wrote!  :icon_redface:  :icon_mrgreen:
Title: Re: EM3207 (v1.1) - MN3207 based EHX Electric Mistress (9V) clone
Post by: 12Bass on August 28, 2011, 01:02:56 PM
Re: BBD operation

If I'm understanding correctly, Igor is saying that past a certain clock rate the BBD cannot effectively transfer a full charge from cell to cell and begins to lose output.   This loss of transfer efficiency would also appear to depend on the relative spacing and shape of the clock pulses.  I wish that I had an oscilloscope so that I could observe the changes in the clock signal as frequency goes up, plus the impact on the audio signal.  Even though this technology is decades old, it is still quite fascinating! 
Title: Re: EM3207 (v1.1) - MN3207 based EHX Electric Mistress (9V) clone
Post by: Eduard_Solderingironhands on August 28, 2011, 02:11:28 PM
Hello,

I can confirm the volume loss of the BBD at very high clock frequencies. Today I managed to to get the LFO and VCO to make the MN3207 sweep from 0.2 to 8 ms. Although the MN3207 is working up to 2.56 MHz (0.2 ms delay) there is no effect audible at these short delays.

I decided to quit developing the Mistress and get a used vintage one.

In case anyone wants to continue development and put the mojo in the mistress, here is my new VCO:
(http://www.metzgerralf.de/elekt/mistress/VCO_new.jpg)

(http://www.metzgerralf.de/elekt/mistress/VCO_new_2.jpg)
Vcrtl_min = 1,60 V, Vcrtl_max = 6.0 V for the new VCO.

For the LFO I changed R22 to 15k + 220, R21 to 10k, and R27 to 100k. The LFO would require a bit more fine tuning.

Best wishes

Ralf
Title: Re: EM3207 (v1.1) - MN3207 based EHX Electric Mistress (9V) clone
Post by: Thomeeque on August 28, 2011, 06:05:56 PM
 Interesting posts, guys, thanks Igor for jumping in!

 Ralf, that clock looks impressive! Was is possible to get lower frequencies yet?

 I did measure GAIN/CLOCK characteristic of my unit:

 VCC = 10VDC
 R34 = 1k
 IC4 = Tesla MAB311
 fCLOCK = 40kHz ~ 3MHz

 Input = 200Hz / 525Hz / 1.5kHz sinus adjusted for 1VPP at pin 3 (input) of BBD

 GAIN is ratio between peek-to-peek voltages at R15 and at pin 3 (input) of BBD, measured by Velleman PPS10 oscilloscope.

 FILTER-MATRIX mode, COLOR at 0.

 (http://thmq.mysteria.cz/em3207/thumb/EM3207_gain_at_R15_dB_3MHz.gif) (http://thmq.mysteria.cz/em3207/big/EM3207_gain_at_R15_dB_3MHz.gif)
 (click pic for hires)

 Results were quite surprising (for me) - characteristic depends on input signal frequency and for some (low) input frequencies gain drop stops around 1400kHz and gain slightly grows again (!!) with higher clock. For higher frequencies drop is continual and signal gets distorted above 2.4MHz (there is maybe space for bias voltage tweaking yet).

 T.
Title: Re: EM3207 (v1.1) - MN3207 based EHX Electric Mistress (9V) clone
Post by: Valentinych on August 29, 2011, 02:18:46 AM
Guys, I think we speak, but often do not understand each other.
Let us define some terms to prevent misinterpretation.

Fclock (Fcp) - frequency phased control impulses BBD on the pins 2, 6 of chip MN3207.
To obtain the time delay our BBD (MN3x07) from 16 ms to 0.4 ms this frequency should vary from 32 kHz to 1280 kHz.
Increase Fcp over 1.3-1.5 MHz is meaningless, because a delay of less than 0.3 ms effect does not occur even in filter-matrix mode.

Fvco – the output of the VCO frequency. From Thomas it is pin 7 of chip LM311.
At this point, the frequency shall be two times higher than at the entrances to the CP1 and SP2 MN3207.  Mean Fvco range must be between 64 kHz to 2560 kHz.

Even if a VCO using MN3102, then Fvco will not be equal to Fcp: on pins 5, 6, 7 of MN3102 the frequency is X (Fvco), and the pins 2, 4 of MN3102 the frequency is X/2 (Fcp).

The last graph by Thomas cannot be analysed without considering frequency characteristics throughout the schematic.
The signal is filtered before BBD and after BBD. Likely rise gain at frequencies below 1 kHz depends not on MN3207, but on amplitude-frequency characteristics of the entire tract.
Title: Re: EM3207 (v1.1) - MN3207 based EHX Electric Mistress (9V) clone
Post by: Eduard_Solderingironhands on August 29, 2011, 05:24:36 AM
Hello Igor,

If you take a look at page 2 of this thread you will see that Fclock (Fcp) of the vintage EM goes from 1280 kHz to 29 kHZ which equals a delay of 0.2 ms to 8.8 ms by the SAD1024. The very short delay of 0.2 ms is clearly hearable and the difference why the vintage versions sounds different than the new Deluxe or DIY versions.

As the MN3207 has 1024 buckets instead of the 512 of the SAD1024 we need Fclock twice as fast which is 2560 kHZ to 58 ms. Fvco must be evan twice (5120 kHZ to 116 kHz).

Best wishes

Ralf
Title: Re: EM3207 (v1.1) - MN3207 based EHX Electric Mistress (9V) clone
Post by: Thomeeque on August 29, 2011, 05:24:48 AM
Guys, I think we speak, but often do not understand each other.
Let us define some terms to prevent misinterpretation.

Fclock (Fcp) - frequency phased control impulses BBD on the pins 2, 6 of chip MN3207.

 Everywhere in this thread where I do mention clock frequency, fCLOCK, fc etc., I mean frequency at BBD's clock pins (CP1/CP2 of MN3x07, Φ1A~2B of SA1024), fCP.

To obtain the time delay our BBD (MN3x07) from 16 ms to 0.4 ms this frequency should vary from 32 kHz to 1280 kHz.
Increase Fcp over 1.3-1.5 MHz is meaningless, because a delay of less than 0.3 ms effect does not occur even in filter-matrix mode.

 Delay of less than 0.3 ms occures in FLANGE mode of my friend's vintage DEM15 I have measured and recorded (http://www.diystompboxes.com/smfforum/index.php?topic=91981.msg792520#msg792520). FLANGE mode range is slightly bigger than F-M mode range in case of this unit.

Fvco – the output of the VCO frequency. From Thomas it is pin 7 of chip LM311.
At this point, the frequency shall be two times higher than at the entrances to the CP1 and SP2 MN3207.
Even if a VCO using MN3102, then Fvco will not be equal to Fcp: on pins 5, 6, 7 of MN3102 the frequency is X (Fvco), and the pins 2, 4 of MN3102 the frequency is X/2 (Fcp).

 Yep.

The last graph by Thomas cannot be analysed without considering frequency characteristics throughout the schematic.
The signal is filtered before BBD and after BBD. Likely rise gain at frequencies below 1 kHz depends not on MN3207, but on amplitude-frequency characteristics of the entire tract.

 Filtering before BBD is not relevant, as stated above amplitude at the very input was adjusted to be 1VPP at the BBD input before each measurement.

 Filtering after BBD (basically only R12-R14 + C17, I did measure "output" voltage at the R15 ~ Q1 buffer output) is not relevant either - first because even at 1.5kHz it has almost no impact on passing signal (C17=680pF @ 1.5kHz ~ 160kΩ) and second because frequency of passing signal remains constant during the measurement, it should not alter shape of the GAIN/CLOCK characteristic (actually, it could alter it as it forms load for BBD outputs, but I believe it's not what you are saying), it would just move it up or down.

 T.
Title: Re: EM3207 (v1.1) - MN3207 based EHX Electric Mistress (9V) clone
Post by: Thomeeque on August 29, 2011, 05:43:41 AM
I can confirm the volume loss of the BBD at very high clock frequencies. Today I managed to to get the LFO and VCO to make the MN3207 sweep from 0.2 to 8 ms. Although the MN3207 is working up to 2.56 MHz (0.2 ms delay) there is no effect audible at these short delays.

 Ralf, what BBD chip did you use exactly? MN3207 (Panasonic/Matsushita), BL3207, V3207..?

 Btw. was R2 necessary in your new LM319 VCO?

 Cheers, T.
Title: Re: EM3207 (v1.1) - MN3207 based EHX Electric Mistress (9V) clone
Post by: Valentinych on August 29, 2011, 06:31:37 AM
Hi, Ralf!
I agree with what you wrote.
However, if you look in datasheet SAD1024, you can see that this chip is designed to work with frequency up to 1 MHz. 
The manufacturer guarantees the work of MN3207 only up to the frequency of 200 kHz, and MN3007 even less – up to 100 kHz. Increase up to 1.2 Fclock -1.5 MHz to SAD1024 practically does not affect the chip. 
But to get the same delay will increase MN3207/3007 Fclock in 25/50 (!) times for guaranteed producer regime.  Yes, MN3207 is operating at a frequency of up to 2-2, 5 MHz, but how? ... I think is bad …

That is why device at MN3x07 never will work the same way as device at SAD1024.

Thomas, I just said!  :icon_lol:

Igor
Title: Re: EM3207 (v1.1) - MN3207 based EHX Electric Mistress (9V) clone
Post by: Thomeeque on August 29, 2011, 08:17:52 AM
But to get the same delay will increase MN3207/3007 Fclock in 25/50 (!) times for guaranteed producer regime.

 I believe it's half (12.5/25)

Yes, MN3207 is operating at a frequency of up to 2-2, 5 MHz, but how? ... I think is bad …
 That is why device at MN3x07 never will work the same way as device at SAD1024.

 Yes, it probably will not, but it still might be interesting..

 E.g. at 1.4MHz it works quite well and it's 7-times (14-times in case of MN3007 and I believe in A/DA with 3007 retrofit it's used at similar frequencies) over the limit stated in datasheet, so..

Thomas, I just said!  :icon_lol:

 And I just responded ;)

 Btw. MIC4424 looks like very interesting chip, unfortunately sourcing it looks problematic (none of shops around me sells it, which is something I use as a "criterion" for choosing reasonably obtainable parts) :(

 T.
Title: Re: EM3207 (v1.1) - MN3207 based EHX Electric Mistress (9V) clone
Post by: Thomeeque on August 29, 2011, 09:28:27 AM
But if the output MN3102 to fix an additional buffer (4049) as in the diagram by Thomas from the first message, everything is great!

 So, I wonder how this Wave Forming block inside MN3102 looks like, maybe it's something relatively simple and we could (maybe at least partially) implement it externally and put between 4013 and buffer (without need to adopt whole clock for MN3102)..

EDIT: I'll ask in separate thread (Wave Forming block inside MN3101/2 (http://www.diystompboxes.com/smfforum/index.php?topic=93466))..

 T.
Title: Re: EM3207 (v1.1) - MN3207 based EHX Electric Mistress (9V) clone
Post by: 12Bass on August 29, 2011, 09:59:28 AM
However, if you look in datasheet SAD1024, you can see that this chip is designed to work with frequency up to 1 MHz. 
The manufacturer guarantees the work of MN3207 only up to the frequency of 200 kHz, and MN3007 even less – up to 100 kHz. Increase up to 1.2 Fclock -1.5 MHz to SAD1024 practically does not affect the chip.

From my own ADA clone testing, even the venerable SAD1024 loses roughly 2 dB of signal at the highest clock rate (1.3 MHz/0.2 mS) with a 4049 buffer.  Apart from the slight signal loss, the fidelity of the output at high clock rates is impressive.  It will clock even higher, but I don't see the point as there is not much musical information left up there to flange.  IMO, even 0.4 mS is short enough to produce dramatic sweeps. 
Title: Re: EM3207 (v1.1) - MN3207 based EHX Electric Mistress (9V) clone
Post by: Valentinych on August 29, 2011, 01:42:24 PM
How many people, so many opinions. And each of their rights. :)
Title: Re: EM3207 (v1.1) - MN3207 based EHX Electric Mistress (9V) clone
Post by: Eduard_Solderingironhands on August 29, 2011, 02:02:08 PM
Hello Thomas,

I don't know if R2 in my new VCO is necessary, because I haven't tried without. R1 is necessary.

Here is my MN3207:
(http://www.metzgerralf.de/elekt/mistress/mn3207.jpg)

Best wishes

Ralf
Title: Re: EM3207 (v1.1) - MN3207 based EHX Electric Mistress (9V) clone
Post by: Fender3D on August 29, 2011, 05:29:53 PM

From my own ADA clone testing, even the venerable SAD1024 loses roughly 2 dB of signal at the highest clock rate (1.3 MHz/0.2 mS) with a 4049 buffer.  Apart from the slight signal loss, the fidelity of the output at high clock rates is impressive.  It will clock even higher, but I don't see the point as there is not much musical information left up there to flange.  IMO, even 0.4 mS is short enough to produce dramatic sweeps. 

It is a parallel-multiplex configuration, it has double the number of samples, so it may loose less charges or a lesser percentage of signal in charge...
Title: Re: EM3207 (v1.1) - MN3207 based EHX Electric Mistress (9V) clone
Post by: 12Bass on August 29, 2011, 08:10:31 PM
It is a parallel-multiplex configuration, it has double the number of samples, so it may loose less charges or a lesser percentage of signal in charge...

Not sure why parallel-multiplex would give a gain advantage at high sample rates.  AFAIK, it just doubles the number of samples per clock, but shouldn't impact amplitude versus clock rate.  Guess it might be more fair to compare it with the MN3010 if we wanted to eliminate that variable.  Reticon's somewhat different process and lower clock capacitance might have something to do with it.  Perhaps more to the point is that we're comparing a dual 512-stage BBD to single 1024-stage units which have to be clocked twice as fast to reach the same delay time.  Even if amplitude loss were the same for a given clock rate, it makes sense that the MN3x07 devices would be at a disadvantage if they are clocked at double the frequency.
Title: Re: EM3207 (v1.1) - MN3207 based EHX Electric Mistress (9V) clone
Post by: Fender3D on August 29, 2011, 08:19:41 PM
The BBD's dark side is the issue the caps (buckets) tend to loose their charge, it's just a matter of time...
With double the samples you have a higher waveform "definition", so you should get a lower loss of signal since it belong to a smaller part of the waveform (assuming the same loss as normal mode).
Title: Re: EM3207 (v1.1) - MN3207 based EHX Electric Mistress (9V) clone
Post by: blueduck577 on August 30, 2011, 05:32:08 PM
Don't mean to detract, but I've got a question from Page 2:

Red values/line represent calculated BBD delay time (=512/(2*fCLOCK) here)

How did you get that formula?  Looking at Reticon's datasheets, they state:

So:
d = N/fs
d = N*(1/fs)
d = 2N/fc

We have this information on the second page:
If you take a look at page 2 of this thread you will see that Fclock (Fcp) of the vintage EM goes from 1280 kHz to 29 kHZ which equals a delay of 0.2 ms to 8.8 ms by the

According to my calculations, a clock rate of 1280 kHz and 512 stages would result in a delay of .8 ms, not .2 ms.
Title: Re: EM3207 (v1.1) - MN3207 based EHX Electric Mistress (9V) clone
Post by: Eduard_Solderingironhands on August 30, 2011, 06:06:17 PM
Hello,

@blueduck577
In my datasheet it says "Delay is 512 clock half periods...". Further on it is defined what a clock period is.
One clock half period is 1/2 * 1/fclock = 1 / (2 * fclock).
d = 512 / (2 * fclock)

d = 512 / (2 * 1260 kHz) = 0,2 ms

Best wishes

Ralf
Title: Re: EM3207 (v1.1) - MN3207 based EHX Electric Mistress (9V) clone
Post by: 12Bass on August 30, 2011, 06:33:38 PM
As I understand it, the number of samples in a BBD is one half of the number of stages.  Thus, a 1024-stage device produces 512 samples, while a 512-stage device produces 256 samples. 

To determine the clock rate for a given delay time, calculate the reciprocal of the delay time divided by the number of samples.

Thus, the clock rate for 0.2 mS for a 1024-stage BBD would be: 1 / (0.0002 / 512) = 2.56 MHz
 
Title: Re: EM3207 (v1.1) - MN3207 based EHX Electric Mistress (9V) clone
Post by: Keeb on September 01, 2011, 04:22:33 AM
First off, let me just start off by saying that you guys really impress me. I do not understand all your calculations and simulations but this is exactly why I love this forum. Friendly, competent people helping people like me understanding circuits!

I would also like to thank Thomeeque for replying to my PM and making it public for everyone to see (the questions he answered a couple of pages back were mine).
So, I built this thing and it passes a clean signal. The only part I substituted were the 22K trim pot, I used a 25K instead which shouldn't matter anyway. Other than that I did not use any modification (no cap parallel to C17 for instance). I built it according to the PDF but without the 100n power filtering caps. I found the correct Zener diode on eBay (neither Banzaimusic or Musikding had it).

I took measurements with all pots about half way up and the trimmers were set up to about half way apart from the 100K multi turn which I turned till the sound distorted and faded away and then dialed it back until a clean signal was passing again.

NEW VOLTAGES BELOW!

I was using a wall wart producing about 8.3V.

IC1 4558

1 2.58
2 2.52
3 1.33
4 0
5 2.13
6 2.35
7 2.10
8 8.12

IC2 MN3207

1 0
2 0
3 2.10
4 7.57
5 8.12
6 8.12
7 3.12
8 3.47

IC3 LM324

1  2.01
2  0.92
3  0.92
4  8.06
5  5.10 - 2.10
6  3.58
7  6.78
8  4.12 - 2.6 (in steps of 0.06)
9  3.64
10 3.57
11 0
12 2.26
13 2.31
14 2.32

IC4 LM311

1 0
2 2.42
3 2.42
4 0
5 8.12
6 8.12
7 8.04
8 8.12

IC5 4013

1  0
2  8.12
3  8.05
4  0
5  8.13
6  0
7  0
8  0
9  0
10 0
11 0
12 0
13 8.12
14 8.12

IC6 4049 unbuffered

1  8.13
2  8.13
3  0
4  0
5  8.13
6  8.13
7  0
8  0
9  8.12
10 0
11 8.12
12 0
13 0
14 0
15 8.12
16 0

Q1 2n3904

E 1.77
B 2.34
C 8.13

Q2 2n5087

E 7.90
B 6.96
C 2.60

D1 1n4001

+ 8.13
- 7.75

D2 1n4148

+ 2.61
- 8.05

D3 Zener 10V/5W

+ 0
- 8.13

Right off the bat CD4013 doesn't seem right but I have no voltages to compare with. Could anyone please post their voltages for me to compare?
Is there anything else I should be looking for?
The 100K trim pot regulates pin 12 on LM324 right? What should that be set to?

Once again, thank you guys for making the effort and especially Thomeeque for making the excellent layout and PDF!
Title: Re: EM3207 (v1.1) - MN3207 based EHX Electric Mistress (9V) clone
Post by: Fender3D on September 01, 2011, 05:06:22 AM
0V on 4049 pin 16 is wrong
it looks like your 311 is not oscillating...
Title: Re: EM3207 (v1.1) - MN3207 based EHX Electric Mistress (9V) clone
Post by: Thomeeque on September 01, 2011, 05:15:44 AM
0V on 4049 pin 16 is wrong

 4049 pin 16 in N.C., I'd say it's alright..

 I have to spend more time with it yet, but I can see that clock (CP1/CP2) signals are frozen (CP1 = 0V, CP2 = VCC).

The 100K trim pot regulates pin 12 on LM324 right? What should that be set to?

 BBD Bias (DC at pin 3 of MN3207) should be set by this trim (RT2) to cca 4.9V* for VCC=8.3V and fine-tuned later for minimal distortion at BBD output.

 More later, T.

* (http://thmq.mysteria.cz/em3207/build/MN3207_DC_Bias_Thmq_400.gif)
Title: Re: EM3207 (v1.1) - MN3207 based EHX Electric Mistress (9V) clone
Post by: Fender3D on September 01, 2011, 05:27:30 AM
holy crap...
it is a CMOS with non-standard supply pin layout...
my bad, I did just auto-reply...
anyway you have no clock on 4013 pin 3
Title: Re: EM3207 (v1.1) - MN3207 based EHX Electric Mistress (9V) clone
Post by: Thomeeque on September 01, 2011, 05:54:14 AM
 Hmm, voltage at Q2/C must be exactly same as is at IC4/pin 3 (it's directly connected), can you check it again? Maybe PCB trace is broken - it would brake clock for sure..
Title: Re: EM3207 (v1.1) - MN3207 based EHX Electric Mistress (9V) clone
Post by: Keeb on September 01, 2011, 05:59:12 AM
Thanks so much guys!
Any suggestions on the other trim pots?

My circuit is only oscillating on LM324 pin 5 and 8 and I understand that's a bad thing.
According to (my interpretation of) the schematic these should feed into pin 3 of the LM324 (when in flange mode) and then go to pin 2 on the LM311.
Should pin 2 on the LM311 oscillate?

When you say CP1 and CP2, are you talking about CD4013 pin 3 and 11?

EDIT; I'll go check right away!

EDIT 2; I measured again and they are both at 2.74. Could this be because I adjusted the trimpot or should I retake the voltages?

EDIT 3; I remeasured all the voltages, quite a difference on the 4558.

IC1 4558

1 5.18
2 5.12
3 2.46
4 0
5 4.51
6 4.97
7 4.74
8 8.13

IC2 MN3207

1 0
2 0
3 4.74
4 7.58
5 8.13
6 8.13
7 3.13
8 3.48

IC3 LM324

1  2.45
2  0.92
3  0.92
4  8.07
5  2.10 - 5.00
6  3.58
7  6.78
8  2.60 - 4.40
9  3.64
10 3.58
11 0
12 4.82
13 4.94
14 4.94

IC4 LM311

1 0
2 2.74
3 2.74
4 0
5 8.13
6 8.13
7 8.05
8 8.13
IC5 4013

1  0
2  8.12
3  8.05
4  0
5  8.13
6  0
7  0
8  0
9  0
10 0
11 0
12 8.12
13 0
14 8.13

IC6 4049

1  8.13
2  8.13
3  0
4  0
5  8.12
6  8.13
7  0
8  0
9  4.26
10 0
11 8.13
12 0
13 0
14 0
15 8.13
16 0

Q1 2n3904

E 8.13
B 3.15
C 2.52

Q2 2n5087

E 7.88
B 6.96
C 2.74

D1 1n4001

+ 8.13
- 7.75

D2 1n4148

+ 2.74
- 8.05

D3 Zener

+ 0
- 8.13
Title: Re: EM3207 (v1.1) - MN3207 based EHX Electric Mistress (9V) clone
Post by: Thomeeque on September 01, 2011, 06:23:04 AM
Thanks so much guys!
Any suggestions on the other trim pots?

 Both set at 50% is ideal for debugging.

My circuit is only oscillating on LM324 pin 5 and 8 and I understand that's a bad thing.
According to (my interpretation of) the schematic these should feed into pin 3 of the LM324 (when in flange mode) and then go to pin 2 on the LM311.
Should pin 2 on the LM311 oscillate?

 In FLANGE mode yes, range should be altered by RANGE pot (in F-M mode there is constant voltage altered again by RANGE pot). Should be close to IC3/pin 1.

 Because even IC3/pin 3 does not oscillate, there is probably problem with your mode switch wiring.

 Anyway, with constant cca 2V at IC4/pin 2 clock should tick (clock signals would be at cca half of VCC) and it does not, so you have problem around clock too.

When you say CP1 and CP2, are you talking about CD4013 pin 3 and 11?

 Nope, CP1/CP2 signals are signals for CP1/CP2 pins (2 and 6) of MN3207. They are "born" at IC5A's outputs +Q and -Q (pins 1 and 2) and should be found all the way to MN3207 (see schematic).

EDIT; I'll go check right away!

EDIT 2; I measured again and they are both at 2.74. Could this be because I adjusted the trimpot or should I retake the voltages?

 Check/fix mode switch, then set F-M mode, set maximal RANGE (IC3/pin 1 should be at cca 3.4VDC), RT3 to max as well and try to measure IC5 pins 1 and 2 (as I said, healthy DC there should be VCC/2, 4.1V in your case).

 T.
Title: Re: EM3207 (v1.1) - MN3207 based EHX Electric Mistress (9V) clone
Post by: Thomeeque on September 01, 2011, 06:38:47 AM
EDIT 3; I remeasured all the voltages, quite a difference on the 4558.

 It's alright, RT2 sets DC bias (Vref) for both halves of IC1 (4558) as well (btw. you should measure Vref at IC1/pin 3 as well, but your DMM has probably 1MΩ input impedance so the voltage there gets divided by 2, as the DMM input forms voltage divider with R3, which is 1MΩ as well).

 T.

 Btw. any chance to try it with different PSU? What PSU you are using exactly?
Title: Re: EM3207 (v1.1) - MN3207 based EHX Electric Mistress (9V) clone
Post by: Valentinych on September 01, 2011, 07:02:46 AM
Guys, it is very difficult to correctly configure the flanger without oscilloscope and FL-oscillator.
But if your have these devices, all very simple.  

To be configurable analog part:

1)   Input devices - on the ground.
2)   POT1 (Color) - on the ground.
3)   Trimmer RT1 - up (the scheme).  
4)   Other trimmers - in the middle position.  
5)   SW1 - in position FILTER-MATRIX.
6)   POT3 (Range) - select frequency VCO ~ 100-200 kHz.  

Then output:
1)   IC1a (pin 1) – DC ~ 1/2 Vcc (Vref).
2)   IC1b output (pin 7) –  DC ~ Vref.
3)   The emitter Q1 – DC ~ (Vref-0.7) volts, with "steps" on Fvco.   

In the input device - DC 1 kHz amplitude 0.2 volts.
 
Then output:
1)   IC1a (pin 1) – clean AC 1 kHz, amplitude ~ 0.6 volts.
2)   IC1b output (pin 7) – pure AC 1 kHz, amplitude ~ 0.6-0.65 volts.
3)   The emitter Q1 – AC 1 kHz, amplitude ~ 0.55 -0.6 volts. Sine, with traces of "steps" on Fvco. Perhaps a small limitation on the top or bottom half wave signal.  
4)   At Pad4 – AC 1 kHz, amplitude of ~ 0.2 volts. DC amplitude depends on the frequency VCO, i.e. from POT3 (Range), and can vary from ~0.02-0.35 volts.

Next:
1)   If the emitter Q1 AC without distortion, start to increase the amplitude of the input signal before the restrictions on the top or bottom half wave signal.
2)   Rotate trimmer RT2 to one or the other way, prior to the disappearance of distortion.
3)   Repeat several times paras. 1), 2), while the symmetric constraint upper and lower half wave signal.

Now turn the knob POT1 (Color) clockwise until it stops. Slowly turn trimmer RT1 before small excitation scheme.  To configure the analog part of the scheme is finished.  

Tomorrow will configure LFO and VCO.  
To be continued.

P.S. I hope, Thomas will not object to …  :icon_rolleyes:
Title: Re: EM3207 (v1.1) - MN3207 based EHX Electric Mistress (9V) clone
Post by: Keeb on September 01, 2011, 07:16:21 AM

 Check/fix mode switch, then set F-M mode, set maximal RANGE (IC3/pin 1 should be at cca 3.4VDC), RT3 to max as well and try to measure IC5 pins 1 and 2 (as I said, healthy DC there should be VCC/2, 4.1V in your case).

 T.

I did this and I get 3.27 on IC3's pin 1. Regardless of RT3 I get  8.12 on pin1 and 0 pin 2 on IC4.
Adjusting the range pot to minimum gives me 0.92 on IC2 pin 1.

I'm using a harley benton powerplant. I guess I could try with a battery (if I can find onw in good condition...otherwise I need to get one).

EDIT; So I realized that in both flange and in filter mode I get 0 and 8.12 on IC4 pin 1 and 2. HOWEVER if I'm not careful while probing them they switch over! Say I'm getting 0 on 1 and 8.12 on 2 and then probe 2 and 3 toghether for just a microsecond and all of a sudden pin 1 reads 8.12 and pin 2 reads 0.
Title: Re: EM3207 (v1.1) - MN3207 based EHX Electric Mistress (9V) clone
Post by: Thomeeque on September 01, 2011, 07:52:44 AM
 Hmm, haven't you forgot to solder jumper connecting right* node of R30 and pin 2 of IC4 (LM311) by any chance (short one close below** LM311)?

 T.

 Btw. hi-res photos from both sides of PCB could help here too.

* on schematic
** on layouts
Title: Re: EM3207 (v1.1) - MN3207 based EHX Electric Mistress (9V) clone
Post by: Thomeeque on September 01, 2011, 08:00:12 AM
P.S. I hope, Thomas will not object to …  :icon_rolleyes:

 I'm learning a lot from your posts, please go ahead :) I just reserve right to disagree time to time ;) T.
Title: Re: EM3207 (v1.1) - MN3207 based EHX Electric Mistress (9V) clone
Post by: Keeb on September 01, 2011, 08:39:11 AM
Hmm, haven't you forgot to solder jumper connecting right* node of R30 and pin 2 of IC4 (LM311) by any chance (short one close below** LM311)?

 T.

 Btw. hi-res photos from both sides of PCB could help here too.

* on schematic
** on layouts

Yeah I have that jumper installed.

Breakthrough though! I found a solder bridge and when I removed it I got a wailing sound flanging in flanger mode and constant in filter mode. The guitar signal is still clean though. Pots seem to work as they change the sound of the wailing in an expected manner.
I retried measuring IC5 pin 1 and 2 they now measure about 4.05 each now (regardless of switch position) and these values appear stable at pin 2 and 6 on the MN3207 as well.
Pin 3 on IC5 now measures 6.42 in filter mode and varies between 6.5 and 2.8 in flanger mode.
Title: Re: EM3207 (v1.1) - MN3207 based EHX Electric Mistress (9V) clone
Post by: Thomeeque on September 01, 2011, 09:31:54 AM
Breakthrough though! I found a solder bridge and when I removed it I got a wailing sound flanging in flanger mode and constant in filter mode. The guitar signal is still clean though. Pots seem to work as they change the sound of the wailing in an expected manner.
I retried measuring IC5 pin 1 and 2 they now measure about 4.05 each now (regardless of switch position) and these values appear stable at pin 2 and 6 on the MN3207 as well.
Pin 3 on IC5 now measures 6.42 in filter mode and varies between 6.5 and 2.8 in flanger mode.

 Well, great, congratulations! :)

 Now just fine-tune it (you can try to follow Igor's instructions), maybe get better PSU in the future (8.3V is pretty pathetic output from PSU specifically designated for guitar pedals and btw. full 9V battery gives around 9.8V - that's why I use 10V PSU mostly)..

 Another advices would be to try:

 - bigger clock capacitor (C17) - 33 or 47pF - for deeper range and more natural sweep
 - B250k as RANGE pot for extended range (lower R29 has similar effect, but not quite the same)
 - compare buffered and unbuffered versions of 4049
 - (temporarily) use 22k trimmer for R18 to try to adjust ration between dry and wet signal to your taste, with R18=10k is wet signal boosted (but it is in case of original 9V EM too)

 Good luck, T.
Title: Re: EM3207 (v1.1) - MN3207 based EHX Electric Mistress (9V) clone
Post by: Keeb on September 01, 2011, 10:43:03 AM
Well, the thing is...

When I adjust RT3 it changes the sound a bit so that seems to be alright. However, when I adjust RT1 above 8 o' clock (using 7 o' clock as all the way down) a wail appears and it's "flanging", regardless if guitar signal is present or not. It gets worse when adjusting RT1 even higher and goes away when lowering POT1/COLOR until there is just a clean guitar signal. Range changes the range of the wail and speed does nothing...

Suggestions?

By the way, I didn't use the in and out grounds, just grounded the board with the middle one next to the VCC then grounded the jacks togetherwith the DC jack. This is how I am used to doing it and I don't think it should matter but I thought I'd mention it.
Title: Re: EM3207 (v1.1) - MN3207 based EHX Electric Mistress (9V) clone
Post by: Thomeeque on September 01, 2011, 10:49:01 AM
speed does nothing...

 Did you add LOG/EXP jumper (Build Notes, bullet 7)? T.
Title: Re: EM3207 (v1.1) - MN3207 based EHX Electric Mistress (9V) clone
Post by: Keeb on September 01, 2011, 11:50:12 AM

 Did you add LOG/EXP jumper (Build Notes, bullet 7)? T.

Guess what? I didn't! Know it does work as long as RT1 isn't set too high!
But maybe that's normal?

I can't thank you guys enough.
/Erik
Title: Re: EM3207 (v1.1) - MN3207 based EHX Electric Mistress (9V) clone
Post by: Ummagumma on September 05, 2011, 07:58:33 AM
3207 version
Here's small preview of what it sounds like:

http://www.box.net/shared/y00q7tinbvrees9f2zsa

Thanks Thomeeque and all of you guys!  :icon_wink:
Title: Re: EM3207 (v1.1) - MN3207 based EHX Electric Mistress (9V) clone
Post by: Thomeeque on September 06, 2011, 05:16:00 AM
 
However, when I adjust RT1 above 8 o' clock (using 7 o' clock as all the way down) a wail appears and it's "flanging", regardless if guitar signal is present or not. It gets worse when adjusting RT1 even higher and goes away when lowering POT1/COLOR until there is just a clean guitar signal.

Guess what? I didn't! Know it does work as long as RT1 isn't set too high!
But maybe that's normal?

 Yes, it is.

 I believe that by "flanging regardless if guitar signal is present or not" you mean self-oscillation (http://www.talkbass.com/forum/f36/what-self-oscillation-287393/).

 RT1 (F. B. trim) is there to set maximal level of the feedback (COLOR) below the point where self-oscillation starts.

 (http://thmq.mysteria.cz/em3207/build/EHXDlxElecMistressFactorySetup2_FB.gif)

 As the signal from MN3207 is louder than from SAD1024, self-oscillation starts sooner.

I can't thank you guys enough.
/Erik

 Yes, you can! :) Make photos, sound samples, videos etc. of your unit and post here, that's what would make me happy most :)

3207 version
Here's small preview of what it sounds like:

http://www.box.net/shared/y00q7tinbvrees9f2zsa

Thanks Thomeeque and all of you guys!  :icon_wink:

 That's what I'm talking about! :) Congratulations, buddy! :)

 Cheers, T.
Title: Re: EM3207 (v1.1) - MN3207 based EHX Electric Mistress (9V) clone
Post by: Keeb on September 08, 2011, 12:20:34 PM
Yes, you can! :) Make photos, sound samples, videos etc. of your unit and post here, that's what would make me happy most :)
 Cheers, T.

Fair enough!

http://www.aronnelson.com/gallery/main.php/v/Keeb/

For the Van Halen bit I turned the flanger on and off (you can probably hear the switching). The slow flanging was inspired by the song "Love" by Smashing Pumpkins (from the great album Mellon Collie and the infinite sadness!).

This info is also available in the gallery:
Quote
I recorded these clips with a LTD EC-400VF through a
15w practice solid state amp by using my iPhone 4 voice memo
function. Not optimal but at least you can hear the flanging.

Clean was done with neck pickup (SD-'59) and a DIY belton brick
reverb pedal after the flanger.

Distorted was done with bridge pickup (dimarzio x2n) through
Tonepad's Dist+ (level max; distortion 12 'o clock) through
flanger and then the reverb again.

Edit; I really want to try this in the loop of my Marshall 6100 (in front of my JCM 800 it was really in your face...). I'll get better clips.
Title: Re: EM3207 (v1.1) - MN3207 based EHX Electric Mistress (9V) clone
Post by: GodSaveMetal on September 08, 2011, 08:01:27 PM
Mr Thomeeque I've made the EH3207 version and it's no work, I I've to desolder the 100nF caps for VCC filtering, resold the sockets of 4049 and 4013, re jumps all for best results; by the facts here are the photos, it is made with webcam sorry for that: : :icon_redface:
My etching PCB (Iron method):
(http://i.imgur.com/qc27U.gif)
The face markers for the components in its side:
(http://i.imgur.com/aFq2x.gif)
All the jumpers in the components side (there are too long):
(http://i.imgur.com/h7li3.gif)
The jumpers in the solder side (um mm perhaps a short circuit in it!):
(http://i.imgur.com/uJb4H.gif)

The resistors solder in order, the trimmer 22K it's changed by a 25K; it will be?? how a 20K in it?? (I'm making the EH3007 version):
(http://i.imgur.com/aIhMX.gif)

The caps also; I used tiny electro caps; 1u and 4u7 are tantalum; the rest are multilayer or Greene caps, the ceramic caps are for pf values:
(http://i.imgur.com/p2qNE.gif)

And all the rest put together; I use a individual PCB for the pots:
(http://i.imgur.com/R1sCB.gif)
(http://i.imgur.com/IYU1V.gif)

Well I tried to solve were are the problems!!!!  :icon_rolleyes:

I'm making the EH3007 version; I'm here with it; a new mask and a new PCB pots:  :icon_razz:
(http://i.imgur.com/Vuw6U.gif)

The jumpers are more shorter all in the components side: :icon_razz:
(http://i.imgur.com/BfOP5.gif)

All the caps in the components side: :icon_biggrin:
(http://i.imgur.com/q6UTY.gif)

There are some questions for the EM3007, I use a 20k trimmer for replace the 22K in the list; the layout of Jorge's FLANGER have a 10V zener, this modified layout have a 15V zener 5W (it is 0,5W???) ; I can use the trimmer substitution value of 20K?  ??? and also the 10V 0,5W zener?  ???

Excuse me man I know it is too much questions; thanks for the adaptation of this, and the time consumed for do my suggestion; your great man!!!  ;D
Title: Re: EM3207 (v1.1) - MN3207 based EHX Electric Mistress (9V) clone
Post by: Thomeeque on September 09, 2011, 07:33:59 AM
 Uhm, OK, so:

 You have build both EM3207 and EM3007?

 None of them works? How exactly it does not work?

 None of your pictures shows mode switch installed..?

 Picture of etched PCB shows many potential bridged traces and few interrupted, but maybe it's just caused by blurred picture - did you carefully checked traces before soldering parts?

 Face markers - hmm, why not, but maybe it would be easier (and safer and definitely quicker) to print layout 1:1 and glue the print to the part side? For EM3207 you can copy/paste layout picture into some graphic software and print it from there (set 1200DPI for the picture, then it should be printed 1:1)* - In case of EM3007 you've got already 1200DPI png.

 All jumpers were meant to be placed on the parts side, but it should not meter.

 I told ya, don't solder 100n VCC filtering caps until it perfectly works.. did you ignore all the other of my build notes too? :icon_evil: ;)

 You can use 20k or 25k for RT3, no problem - if I should choose, I would prefer 25k (gives bigger range of control, 20k cuts it little bit).

 Get cermet multi-turn RT2 for EM3007, common single-turn trimpot may make bias adjustment more tricky (and less stable).

 Voltage of zenner sets maximal VCC - if you will use 10V, you won't be able to feed it by more than 10V. Since MN3007 allows 15V, it would be shame to limit it to 10V just because you don't have 15V zenner at the moment (you may get better performance at 15V).

 It is really 5W to make strong overvoltage "fuse", maybe it's not necessary (read this post (http://www.diystompboxes.com/smfforum/index.php?topic=91981.msg802233#msg802233)) - I really did not expect sourcing 5W zenner to be problem, looks like I was wrong.

 T.

* general note: all graphics inside PDF (except the title page) are 1200DPI bitmaps (and "copy to clipboard" /or other form of export/ is allowed)
Title: Re: EM3207 (v1.1) - MN3207 based EHX Electric Mistress (9V) clone
Post by: GodSaveMetal on September 09, 2011, 01:49:32 PM
OK thanks for the recommendations man I've to resold the EM3207 in the jumpers sections and desolde the VCC 100nF caps too; finishing my EM3007; to compare the sound; the EM3207 only have the sound trough it; no flanger effect !!!! well I have to change some parts and next week I will do some probes; the Jorge's adaptation of these in the large PCB is great but is so big!!!! these is more compact, I made the flanger/filter matrix a footswitch:
(http://i.imgur.com/g3mXu.gif)

The footswitch are DIYer; the case are DIYer, all is hand made; the adhesive is my design; the transparent cover I made myself!! it is pure DIY on all my pedals! ;D
Title: Re: EM3207 (v1.1) - MN3207 based EHX Electric Mistress (9V) clone
Post by: Keeb on September 09, 2011, 07:35:09 PM
OK thanks for the recommendations man I've to resold the EM3207 in the jumpers sections and desolde the VCC 100nF caps too; finishing my EM3007; to compare the sound; the EM3207 only have the sound trough it; no flanger effect !!!! well I have to change some parts and next week I will do some probes; the Jorge's adaptation of these in the large PCB is great but is so big!!!! these is more compact, I made the flanger/filter matrix a footswitch:
(http://i.imgur.com/g3mXu.gif)

The footswitch are DIYer; the case are DIYer, all is hand made; the adhesive is my design; the transparent cover I made myself!! it is pure DIY on all my pedals! ;D

Have you checked your voltages?
If you look a  while back I got some serious help...
Title: Re: EM3207 (v1.1) - MN3207 based EHX Electric Mistress (9V) clone
Post by: oldschoolanalog on September 09, 2011, 08:26:04 PM
Sorry, but after following this thread from it's inception I have to do/say this...
THIS IS A PUBLIC SERVICE ANNOUNCEMENT! PLEASE READ THE FOLLOWING:
Tomas has put more time and effort into this; and all the other projects he has posted; than can be expected from any one person. All are "good to go" and verified working.
PLEASE, PLEASE, PLEASE read the entire pdf/build & calibration notes before embarking on any of his projects. He has spent countless hours testing and writing so folks can  get things right. If you read and follow his instructions; and build with care (no sloppy rush jobs, y'all hear?) there is no reason this should not work properly. Hell, check out the TDA1022 based EM he designed. This MN3207 EM is child's play compared to that. And even a hack like myself got that going on the first shot (IMHO, it sounds better too[the EM/TDA1022 that is...] ;)).
Read the pdf/notes till you really "own" it/them. Then proceed. Some folks will hate me for saying this now; but will thank me later.
Thank you, and happy soldering! ;D
You may now return to your regularly scheduled program...
Title: Re: EM3207 (v1.1) - MN3207 based EHX Electric Mistress (9V) clone
Post by: GodSaveMetal on September 09, 2011, 10:42:41 PM
Thanks to all of you for your preoccupations; my deal is to return on my feet's an resolder the parts I see wrong, on the way I'm doing the EM3007 that i know it function on Jorge's PCB I made the giant ones; this is more compact and it is functional also, I have problems with the MN3207 chip! :icon_frown: but the MN3007 all i proved that are god in the MISTRESS I made! OK thanks man ! :icon_wink:
Title: Re: EM3207 (v1.1) - MN3207 based EHX Electric Mistress (9V) clone
Post by: quarara on September 10, 2011, 03:18:44 AM
Sorry, but after following this thread from it's inception I have to do/say this...
THIS IS A PUBLIC SERVICE ANNOUNCEMENT! PLEASE READ THE FOLLOWING:
Tomas has put more time and effort into this; and all the other projects he has posted; than can be expected from any one person. All are "good to go" and verified working.
PLEASE, PLEASE, PLEASE read the entire pdf/build & calibration notes before embarking on any of his projects. He has spent countless hours testing and writing so folks can  get things right. If you read and follow his instructions; and build with care (no sloppy rush jobs, y'all hear?) there is no reason this should not work properly. Hell, check out the TDA1022 based EM he designed. This MN3207 EM is child's play compared to that. And even a hack like myself got that going on the first shot (IMHO, it sounds better too[the EM/TDA1022 that is...] ;)).
Read the pdf/notes till you really "own" it/them. Then proceed. Some folks will hate me for saying this now; but will thank me later.
Thank you, and happy soldering! ;D
You may now return to your regularly scheduled program...
+1
Title: Re: EM3207 (v1.1) - MN3207 based EHX Electric Mistress (9V) clone
Post by: Thomeeque on September 10, 2011, 07:24:13 PM
Sorry, but after following this thread from it's inception I have to do/say this...
THIS IS A PUBLIC SERVICE ANNOUNCEMENT! PLEASE READ THE FOLLOWING:
Tomas has put more time and effort into this; and all the other projects he has posted; than can be expected from any one person. All are "good to go" and verified working.
PLEASE, PLEASE, PLEASE read the entire pdf/build & calibration notes before embarking on any of his projects. He has spent countless hours testing and writing so folks can  get things right. If you read and follow his instructions; and build with care (no sloppy rush jobs, y'all hear?) there is no reason this should not work properly. Hell, check out the TDA1022 based EM he designed. This MN3207 EM is child's play compared to that. And even a hack like myself got that going on the first shot (IMHO, it sounds better too[the EM/TDA1022 that is...] ;)).
Read the pdf/notes till you really "own" it/them. Then proceed. Some folks will hate me for saying this now; but will thank me later.
Thank you, and happy soldering! ;D
You may now return to your regularly scheduled program...

+1 :icon_mrgreen: Thanks Dave (and Luigi)! T.
Title: Re: EM3207 (v1.1) - MN3207 based EHX Electric Mistress (9V) clone
Post by: njkmonty on September 13, 2011, 07:59:50 AM
Hope I can ask a question without a big "public service announcement" hammered after it! :P
already done the ada build, was going to give this a go,
Have had a light read over the thread, but just wondering was there a preferred build? mn3207 or mn3007? or no notable, sound differences  , only voltage requirements.

i sort of skipped all the scope  results etc :)

I have both chips lying around.


Title: Re: EM3207 (v1.1) - MN3207 based EHX Electric Mistress (9V) clone
Post by: oldschoolanalog on September 13, 2011, 08:27:09 AM
Both.  :icon_eek: ;D
Can never have enough Mistresses...
Title: Re: EM3207 (v1.1) - MN3207 based EHX Electric Mistress (9V) clone
Post by: 12Bass on September 13, 2011, 08:29:47 AM
Hope I can ask a question without a big "public service announcement" hammered after it! :P
already done the ada build, was going to give this a go,
Have had a light read over the thread, but just wondering was there a preferred build? mn3207 or mn3007? or no notable, sound differences  , only voltage requirements.

In theory the MN3007 version should have a bit more headroom, if running at 15 V.  At 9 V, there's probably not much difference.  I'd probably be more inclined to use MN3207 if limited to 9 V.
Title: Re: EM3207 (v1.1) - MN3207 based EHX Electric Mistress (9V) clone
Post by: njkmonty on September 13, 2011, 08:32:05 AM
ho ho ho
i read somewhere in here someone using a bass wanted more headroom, would that be a reason to lean to the mn3007,
and please no jokes about head, getting a room  and mistresses! :)


you answered just while i was posting!
Title: Re: EM3207 (v1.1) - MN3207 based EHX Electric Mistress (9V) clone
Post by: njkmonty on September 13, 2011, 08:37:19 AM
then from what i can see its only one more jumper, and  3 resistors and a zener difference.
i might socket the components and  try both . (would have to connect the jumper though under the board for the mn3207/mn3007 change

also the "colour" pot, is that just another name for "enhance " pot?  like of the ada? gives that metallic sound?
obviously never owned an elect mistr!
Title: Re: EM3207 (v1.1) - MN3207 based EHX Electric Mistress (9V) clone
Post by: oldschoolanalog on September 13, 2011, 08:50:40 AM
ho ho ho...
...and please no jokes about head, getting a room  and mistresses! :)
:icon_lol: Okay, no Ho jokes either...
Yes, color=enhance.
Title: Re: EM3207 (v1.1) - MN3207 based EHX Electric Mistress (9V) clone
Post by: Thomeeque on September 13, 2011, 09:26:02 AM
then from what i can see its only one more jumper, and  3 resistors and a zener difference.
i might socket the components and  try both . (would have to connect the jumper though under the board for the mn3207/mn3007 change

 Yep. I'd say that EM3007 v1.1 PCB is easier adaptable for eventual use of MN3207 then the other way around.
Title: Re: EM3207 (v1.1) - MN3207 based EHX Electric Mistress (9V) clone
Post by: mr_deadmaxxx on September 14, 2011, 04:09:31 AM
i had read almost everything under this thread and i have some questions..

1.) if i were to build this one, (after reading everything from pages 2 to 9) is it still safe to
build the one posted on the very first page? (the one in pdf)

2.) which would be better to build? EM3007 or EM3207?

3.) am i right in saying that EM3207 is only for 9V operation? and EM3007 for 15V? can't they both work at 9V?

anyways, im just a little confused which of them (EM3207 or EM3007) is much better to build compared to the other.

thanks..and nice flange.. +1
Title: Re: EM3207 (v1.1) - MN3207 based EHX Electric Mistress (9V) clone
Post by: njkmonty on September 14, 2011, 06:48:42 AM
from my understanding there will be little difference, (little more headroom , who knows!)
mn3007 requires 15v dc power supply, so a bit more hassle if you only have a 9v supply
im pretty sure the pdf (9v mn3207)at beginning is still good to go, , it can with a little tinkering be adjusted back to suit mn3007
although as i think Thomeeque was saying was that it would be an easier conversion to do his earlier layout (which i think is bigger too, if wanting to be easilier going back and forth.) but from memory the pdf is a nicer compactier layout.?
is what im saying right,...Thomeeque ??????
i think what the conclusion is ....
just build the pdf version,  K>I>S>S !

can both work from 9v??

well technically yes... but with more adjustments,mn3007  would need a surge pump  like off moosapotumus  ada flanger lt054 i think?
look at this link

http://moosapotamus.net/IDEAS/ADAflanger/ADA_MN3007/FlangerClone_SCH_rev5_MN3007_jan2010.gif

right in the middle the circuit where it has got 9v coming in and 18v coming out heading towards 15v regulator, but also too ,like mine you loose a little in forward voltage etc from diodes and stuff, again i think! which means by the time it gets to the regulator your hoping you have 9v coming into the surge pump and getting as close to 18v as you can for the regulator!,

again more thinks to add!
Title: Re: EM3207 (v1.1) - MN3207 based EHX Electric Mistress (9V) clone
Post by: oldschoolanalog on September 14, 2011, 07:38:49 AM
The MN3007 works just fine @ 9V.
Title: Re: EM3207 (v1.1) - MN3207 based EHX Electric Mistress (9V) clone
Post by: njkmonty on September 14, 2011, 07:47:35 AM
where did i read that it reads 15v?
bugger me! ???

i do believe your right, but ive got a copy of a panasonic 1024 stage low noise bbd, and it says
supply voltage -15  units v
then whats that all about ,
for some reason i thought  the 3000 series was for 15v and 3200 was for 9v
oh well, dont i look a noob!
Title: Re: EM3207 (v1.1) - MN3207 based EHX Electric Mistress (9V) clone
Post by: Fender3D on September 14, 2011, 09:06:01 AM
MN3007 will work @ 9V.
But to achieve the same delay range you must have somewhat more than 10V to drive VCO properly.
Title: Re: EM3207 (v1.1) - MN3207 based EHX Electric Mistress (9V) clone
Post by: sugonidamaso on September 15, 2011, 03:58:48 AM
Hello,
I already build 3207 (salvaged from the very big electric mistress pcb). My question is that why the flanging seems fast?(like siren of an ambulance). I changed the 2n5057(which is not available in my area) tranny to a 3906(twisted other way around).Also with 2n4250. Should the 5057 be? In the earlier post Thomas said it will change the frequency and sweep. In addition, when I rotated the 1M pot maximum it squeals! And the 10k color pot also won't work. Thank you very much!(http://file:///C:/Users/Barabbas/Desktop/IMG_6350.JPG)(http://file:///C:/Users/Barabbas/Desktop/IMG_6349.JPG)
Title: Re: EM3207 (v1.1) - MN3207 based EHX Electric Mistress (9V) clone
Post by: njkmonty on September 15, 2011, 07:22:09 AM
my ada diy flanger  has only sounded like an ambulance when the guitar signal ground wasn't connected to the power supply ground, (as mine is not in an enclosure as yet.) but you seem to have other troubles aswell?




Title: Re: EM3207 (v1.1) - MN3207 based EHX Electric Mistress (9V) clone
Post by: sugonidamaso on September 15, 2011, 08:51:18 AM
Yes. Even connected to my guitar. I'm clueless ??? ??? ???
Title: Re: EM3207 (v1.1) - MN3207 based EHX Electric Mistress (9V) clone
Post by: sugonidamaso on September 15, 2011, 11:34:36 AM
Here's some of the pictures. Hope will help. Thanks!I have no available on hand regarding R5=4.7k
http://i1225.photobucket.com/albums/ee389/sugonidamaso/IMG_6349.jpg
http://i1225.photobucket.com/albums/ee389/sugonidamaso/IMG_6350.jpg
Title: Re: EM3207 (v1.1) - MN3207 based EHX Electric Mistress (9V) clone
Post by: Govmnt_Lacky on September 15, 2011, 11:49:39 AM
Here's some of the pictures. Hope will help. Thanks!I have no available on hand regarding R5=4.7k
http://i1225.photobucket.com/albums/ee389/sugonidamaso/IMG_6349.jpg
http://i1225.photobucket.com/albums/ee389/sugonidamaso/IMG_6350.jpg


On initial inspection, and looking at your picture of the copper trace side of the board. I see two things:

1) This DEFINITELY needs a look over for solder bridges. Be sure to look for those and eliminate any.

2) Looking at the wide copper trace in the middle of the board (in the picture) if you follow it down towards the point where it looks like some of the trace did not transfer well. Check there to make sure you do not have a micro-break in the trace. It looks like there could be a tiny break in the trace there.

Goos Luck  ;D
Title: Re: EM3207 (v1.1) - MN3207 based EHX Electric Mistress (9V) clone
Post by: sugonidamaso on September 15, 2011, 01:51:26 PM
Will try to look again Sir! Thank you! :icon_mrgreen:
Title: Re: EM3207 (v1.1) - MN3207 based EHX Electric Mistress (9V) clone
Post by: sugonidamaso on September 16, 2011, 02:07:24 AM
Hello again,
As per Govmnt_Lacky advise, I already looked regarding solder bridges and all. The transfer did well as per continuity test. And still having the same problem. :icon_cry:
Title: Re: EM3207 (v1.1) - MN3207 based EHX Electric Mistress (9V) clone
Post by: mr_deadmaxxx on September 16, 2011, 02:19:09 AM
you made the 3207 right?

i still wonder why others chose the 3007..
maybe it's better than the 3207?
Title: Re: EM3207 (v1.1) - MN3207 based EHX Electric Mistress (9V) clone
Post by: sugonidamaso on September 16, 2011, 02:26:14 AM
Yes the 3207. I have no idea sir regarding that matter. Will consider that option though.
Title: Re: EM3207 (v1.1) - MN3207 based EHX Electric Mistress (9V) clone
Post by: mr_deadmaxxx on September 16, 2011, 02:31:04 AM
for how much did you purchase your MN3207?
Title: Re: EM3207 (v1.1) - MN3207 based EHX Electric Mistress (9V) clone
Post by: sugonidamaso on September 16, 2011, 02:34:35 AM
It's about less than a dollar here in my area. About a quarter I think.
Title: Re: EM3207 (v1.1) - MN3207 based EHX Electric Mistress (9V) clone
Post by: mr_deadmaxxx on September 16, 2011, 02:49:28 AM
how much exactly? just let me deal with the dollar-conversion..
what's the currency?

anyways, will you post your sound samples here after your EM3207 is working?
Title: Re: EM3207 (v1.1) - MN3207 based EHX Electric Mistress (9V) clone
Post by: sugonidamaso on September 16, 2011, 03:00:06 AM
It's 26 pesos here in the Philippines. ERRATUM: So SLOPPY of me!So sorry!I interchanged the 1M pot the 10k pot! :icon_redface: :icon_redface: :icon_redface: Flanging's fine now,but the 10k pot-color still squeals @ Max.
Title: Re: EM3207 (v1.1) - MN3207 based EHX Electric Mistress (9V) clone
Post by: mr_deadmaxxx on September 16, 2011, 03:05:06 AM
did you also apply the SPDT switch, the same as the one in the picture of Mr. T?
Title: Re: EM3207 (v1.1) - MN3207 based EHX Electric Mistress (9V) clone
Post by: sugonidamaso on September 16, 2011, 03:27:25 AM
No Sir. I definitely checked on that.Well considering the facts, I was wrong. :icon_mrgreen: :icon_redface: The 10k pot--- adjusted the RT1 and that's it. Thank so much for the help! :icon_redface: Mr. Deadmaxxx and Govmnt_Lacky thanks! will consider the 3007 still. I have 3007 lying around but no 15v zener though. Correct me if I'm wrong but in my understanding the R10&R11 should be interchanged?In the 3007 of course.
Title: Re: EM3207 (v1.1) - MN3207 based EHX Electric Mistress (9V) clone
Post by: mr_deadmaxxx on September 16, 2011, 04:12:38 AM
is it working now?
how does it sound?
is it worth building?
Title: Re: EM3207 (v1.1) - MN3207 based EHX Electric Mistress (9V) clone
Post by: sugonidamaso on September 16, 2011, 04:15:52 AM
yes it's worth building. but i have to try 3007 and some mods recommended by Thomas. ;D
Title: Re: EM3207 (v1.1) - MN3207 based EHX Electric Mistress (9V) clone
Post by: njkmonty on September 18, 2011, 03:13:59 AM
what are the explainable sound differences do you think with this build and the moosapotomus mn3007 ada flanger ?
or is it too difficult to verbalize on virtual paper?
 :icon_confused:
Title: Re: EM3207 (v1.1) - MN3207 based EHX Electric Mistress (9V) clone
Post by: sugonidamaso on September 18, 2011, 11:34:30 AM
i can tell you that the ada flanger is more of a jet than 3207. but 3207 is much easier for me to acquire than ada. :icon_mrgreen: SAD chip is not available here in my area.
Title: Re: EM3207 (v1.1) - MN3207 based EHX Electric Mistress (9V) clone
Post by: njkmonty on September 19, 2011, 08:06:11 AM
i  couldnt get hands on sad1024 one either, but like a few on here built this  

http://www.moosapotamus.net/IDEAS/ADAflanger/ADA_MN3007/ADA%20Flanger%20Clone%20Build%20Instructions%20PCB%20rev5%20MN3007%20Jan2010.pdf


http://moosapotamus.net/IDEAS/ADAflanger/ADAflanger.html


i think hes still got some pcbs , great quality

i finally got mine to work and very happy, to me sounds just like the demos of youtube.

Title: Re: EM3207 (v1.1) - MN3207 based EHX Electric Mistress (9V) clone
Post by: njkmonty on September 19, 2011, 08:09:46 AM
ask charlie,...

   charlie@moosapotamus.net
Title: Re: EM3207 (v1.1) - MN3207 based EHX Electric Mistress (9V) clone
Post by: sugonidamaso on September 19, 2011, 09:29:02 AM
Thanks njkmonty!Unfortunately, it is too big in my board. I'm 1590b casing kinda guy- :icon_redface: majority of my pedals are. ;) Furthermore, yes! I did saw your video way back! Cool! Wish it was built like a boss casing BF kinda. I built the BIG PCB mistress last year. It was just laying around and I couldn't get in to my boards! But considering the facts, will consider in the future to built this ADA ;)
Title: Re: EM3207 (v1.1) - MN3207 based EHX Electric Mistress (9V) clone
Post by: oldschoolanalog on September 19, 2011, 09:46:48 PM
The A/DA is well worth the pedalboard real estate it takes up.  :icon_cool:
Title: Re: EM3207 (v1.1) - MN3207 based EHX Electric Mistress (9V) clone
Post by: sugonidamaso on September 19, 2011, 11:43:17 PM
Yess indeed sir. Will consider of course. Thanks! How about the new flanger-AF2 ;)
Title: Re: EM3207 (v1.1) - MN3207 based EHX Electric Mistress (9V) clone
Post by: njkmonty on September 20, 2011, 02:12:50 AM
http://www.diystompboxes.com/smfforum/index.php?topic=74367.msg792704#msg792704

try this path, Valoosj  managed to fit an ada into a  1590a!!  no real estate props there!
Title: Re: EM3207 (v1.1) - MN3207 based EHX Electric Mistress (9V) clone
Post by: sugonidamaso on September 20, 2011, 04:14:24 AM
That is a one sick man! I must tell you... :icon_mrgreen:
Title: Re: EM3207 (v1.1) - MN3207 based EHX Electric Mistress (9V) clone
Post by: judgemingus on September 21, 2011, 02:00:58 AM
It looks like a 1590B to me, but that is still a great effort!
Title: Re: EM3207 (v1.1) - MN3207 based EHX Electric Mistress (9V) clone
Post by: njkmonty on September 21, 2011, 07:30:08 AM
story "B" your right!
Title: Re: EM3207 (v1.1) - MN3207 based EHX Electric Mistress (9V) clone
Post by: tiago razera on September 21, 2011, 03:44:29 PM
Hi all.

Just completed this build. To me, it sounds great. It does all the Gilmour The Wall stuff (that's what got me interested), and some jet flanging.

The layout is perfect, worked on the first go.

Thanks Thomeeque for the great work. It's very compact. Indeed I recomend double-checking every step as you do, since the board is so populated it's difficult to insert/remove components later.

Since i've built this with components already on hands, I had to do some modifications. One of them is substitute the two series 33uF LFO caps for one 47uF and one 22uF. Don't know if it makes any difference on the shape of the waveform or other aspect, but works well.

Later I will post pictures and some sound samples.

Tiago
Title: Re: EM3207 (v1.1) - MN3207 based EHX Electric Mistress (9V) clone
Post by: mr_deadmaxxx on September 22, 2011, 03:02:29 AM
"the" jet flanging? really?
i thought this pedal can't do that.
Title: Re: EM3207 (v1.1) - MN3207 based EHX Electric Mistress (9V) clone
Post by: Thomeeque on September 22, 2011, 05:07:52 AM
Hi all. Just completed this build..

 Hey Tiago, great, congratulations! :)

 I'm glad you like it and I'm looking forward to see/hear your photos and sound samples*!

..substitute the two series 33uF LFO caps for one 47uF and one 22uF..

 I know that this anti-serial combination of equal electrolytics makes cheap non-polarised capacitor (with 1/2 capacity) and instinct tells me, that these two capacitors should be as equal as possible for the best results, but I don't know much about internal "physics" either. If you like the result then it's OK probably, you may just check yet if it did not lead to bigger reverse voltage stress for those capacitors (measure DC at each with slowest RATE set).

 Cheers, T.

 *If it would not make you too much trouble, please list all mods you have done (at least those which could affect sound somehow) together with sound samples.
Title: Re: EM3207 (v1.1) - MN3207 based EHX Electric Mistress (9V) clone
Post by: tiago razera on September 22, 2011, 09:54:01 PM
Hi.

Photo:

http://www.flickr.com/photos/67834577@N03/6174034194/

Sound sample later.
Title: Re: EM3207 (v1.1) - MN3207 based EHX Electric Mistress (9V) clone
Post by: njkmonty on September 25, 2011, 04:26:29 AM
I was wondering if there was a simple odd/even mod similar to the odd/even switch found on ada flanger clone
(see below)

perhaps somewhere near q1(2n3904) or ic1B 4558 from the Thomeequeeque's schematic found on page 1 of this thread?

(http://i999.photobucket.com/albums/af111/njkmonty/ScreenHunter_01Sep251819.jpg)
Title: Re: EM3207 (v1.1) - MN3207 based EHX Electric Mistress (9V) clone
Post by: oldschoolanalog on September 25, 2011, 06:43:56 AM
See PDF for the TDA1022 based EM Thomas designed. Your odd/even answer is there. ;)
Title: Re: EM3207 (v1.1) - MN3207 based EHX Electric Mistress (9V) clone
Post by: njkmonty on September 25, 2011, 07:28:48 AM
i could only find this

http://thmq.mysteria.cz/em1022/index.htm

but couldn't seem to see the odd even switching?
or is it called something else , i notice there is 4 switches
mode
tone feedback
mix
is it one of these?

ive also made a few boards from tonepads,  small clone chorus, "stereo mod schematic" to try to adapt to my ada and  this build, which ive just completed. ive hooked them up and getting  it to work but a little unsure if ive done it correctly, if they are in or out of phase with each etc, you dont mind me asking a few more pics along this line?
http://www.tonepad.com/getFile.asp?id=97
Title: Re: EM3207 (v1.1) - MN3207 based EHX Electric Mistress (9V) clone
Post by: njkmonty on September 25, 2011, 07:45:24 AM
heres the stereo mod
"B" states on the tonepad page 4.5v, should i just connect to pin 5 of the 4558 ic?
(http://i999.photobucket.com/albums/af111/njkmonty/stereomodhelp-1.jpg)
Title: Re: EM3207 (v1.1) - MN3207 based EHX Electric Mistress (9V) clone
Post by: Thomeeque on September 25, 2011, 06:26:00 PM
I was wondering if there was a simple odd/even mod similar to the odd/even switch found on ada flanger clone
(see below)

 I don't think it could be achieved just by some smart rewiring of existing circuitry, but you can build simple add-on like this:

 (http://thmq.mysteria.cz/em3207/build/EM3x07_odd_even_addon.gif)

 IC1A would replace current BBD output buffer (remove Q1 and R15 from EM3x07 board and use it's pads to wire add-on to), IC1B simply inverts BBD output signal (which is what the EVEN mode is all about). R3+C1 integrates BBD output signal to get DC bias for inverter. Other way would be to use Vref from EM3x07 board, but DC level at BBD output differs from Vref, so there would be probably audible pop when S1 was switched.

 Stereo could use signals from this add-on, I'll draw something tomorrow.

i could only find this

http://thmq.mysteria.cz/em1022/index.htm

but couldn't seem to see the odd even switching?
or is it called something else , i notice there is 4 switches
mode
tone feedback
mix
is it one of these?

 Both mix & feedback on POSITIVE = ODD (demo from 0:19 (http://www.youtube.com/watch?v=VXxmixk46Xo&t=0m19s))
 Both mix & feedback on NEGATIVE = EVEN (demo from 2:48 (http://www.youtube.com/watch?v=VXxmixk46Xo&t=2m48s))

 T.
Title: Re: EM3207 (v1.1) - MN3207 based EHX Electric Mistress (9V) clone
Post by: njkmonty on September 26, 2011, 06:24:29 AM
cool thanks heaps,...
i noticed you like your flangers!!!! :)
Title: Re: EM3207 (v1.1) - MN3207 based EHX Electric Mistress (9V) clone
Post by: Thomeeque on September 26, 2011, 07:55:23 AM
cool thanks heaps,...
i noticed you like your flangers!!!! :)

 Yes, I do, you're welcome :)

 Unfortunately stereo won't be that easy as I thought yesterday (pre/de-emphasis and feedback mixed into "dry" path* complicates it little bit). I need to reconfigure add-on above little more.. stay tuned :)

 * it applies to your idea as well - more you would add COLOR, more would be wet signal cancelled in the second channel.

 T.
Title: Re: EM3207 (v1.1) - MN3207 based EHX Electric Mistress (9V) clone
Post by: njkmonty on September 26, 2011, 08:38:48 AM
if its a pain in butt, and a mod not worth the hassle, then dont waste too much of your time!, what im realy after is an ada stereo mod, i just thought that if i made a couple of tonepad boards i could simply just piggyback them on both the ada and your mn3207 mistress! :
one other question, i notice a little "metallic" even when colour is down too minimum . do you just disconnect with a switch 2n2 feedback cap connection to the middle lug of the color pot? (if wanting no feedback at all?
Title: Re: EM3207 (v1.1) - MN3207 based EHX Electric Mistress (9V) clone
Post by: njkmonty on September 29, 2011, 07:12:13 AM
just have to say totally love this build,!  love "the police" tones, and playing around with different ceramic caps  for the clock cap have made it so versatile, its so good ive been having difficulty putting it down, shine on crazy diamonds etc,
i must say, now come to think of it would be have to  am happy to wait for your drawing! ;D
Title: Re: EM3207 (v1.1) - MN3207 based EHX Electric Mistress (9V) clone
Post by: Thomeeque on September 29, 2011, 08:11:02 AM
one other question, i notice a little "metallic" even when colour is down too minimum . do you just disconnect with a switch 2n2 feedback cap connection to the middle lug of the color pot? (if wanting no feedback at all?

 If you have wired everything correctly and COLOR pot is not defective, turning it down to minimum should completely cancel the feedback.. You can try to pull C4 (2n2) out with COLOR at minimum, if it changes, something is wrong.

just have to say totally love this build,!  love "the police" tones, and playing around with different ceramic caps  for the clock cap have made it so versatile, its so good ive been having difficulty putting it down, shine on crazy diamonds etc,

 Hi, it's a really pleasant reading :), congrats and thanks for your feedback!

i must say, now come to think of it would be have to  am happy to wait for your drawing! ;D

 Do you mean stereo "pain in butt" mod? ;) I tell you what, make few sound samples for us and I'll draw it for you, OK? :)

 Cheers, T.
Title: Re: EM3207 (v1.1) - MN3207 based EHX Electric Mistress (9V) clone
Post by: njkmonty on September 29, 2011, 08:35:23 AM
sounds good will do a vid!
the colour pot works fine, ti was more my mistake and interpretation! all good!

i dont normally do mods on builds just because they are available, so after putting this together and being very happy with,
i noticed on page 1 of this thread by "Mark Hammer"

First, there is the obvious possibility of splitting a mono input signal and having two asynchronous flanger outputs.
Second, there is the possibility of having a mixer and combining the two flanger signals into a single more complex mono output.
Third, there is the possibility of lifting the dry signal from each flanger outputs, and running them "stereo-out" to separate amps or mixer channels.  At slow sweep speeds, this can produce both apparent movement as the phase relationship between left and right keeps changing.  It can also produce "flanging in-air" (though that likely requires standing in the sweet spot).  At faster sweep speeds, you get stereo vibrato, which can be interesting.
Fourth, with dry lift, and setting one of them to "filter matrix" (non-swept) mode, combining flanger A and B gets you variations of through-zero flanging.


now i dont see myself using the "filter matrix " too much but, wondered, are some of Marks ideas, worth doing? or going overboard or wait for your post?
i currently have a 4 amp setup, which is why  stereo appeals to me!
jc120
fender twin
slo clone
18 watt tmb
what are your thoughts?

is building 2 boards a bit anal!!!:)?
Title: Re: EM3207 (v1.1) - MN3207 based EHX Electric Mistress (9V) clone
Post by: oldschoolanalog on September 29, 2011, 09:57:11 AM
Put the range pot in a wah type enclosure and you will find yourself using filter matrix mode a lot. :icon_cool:
Title: Re: EM3207 (v1.1) - MN3207 based EHX Electric Mistress (9V) clone
Post by: njkmonty on September 30, 2011, 05:52:20 AM
made another big video but kept stuffing up trying to upload, so had to make a quicker one!
i feel like im trying to keep up with all these flanging threads, but just came across this:

TZF3007 - TZF (short delay) module, MN3007 based

http://www.diystompboxes.com/smfforum/index.php?topic=85977.0


is the tzf what im after for this build???

as promised ......
Title: Re: EM3207 (v1.1) - MN3207 based EHX Electric Mistress (9V) clone
Post by: njkmonty on October 03, 2011, 08:16:57 AM
is this how tzf be applied ????

(http://i999.photobucket.com/albums/af111/njkmonty/Untitled.jpg)
Title: Re: EM3207 (v1.1) - MN3207 based EHX Electric Mistress (9V) clone
Post by: Scruffie on October 03, 2011, 08:24:47 AM
You got it  :)
Title: Re: EM3207 (v1.1) - MN3207 based EHX Electric Mistress (9V) clone
Post by: njkmonty on October 03, 2011, 08:30:15 AM
so just build 2 ?

if i do that as mark hammer suggests on first page of this thread, whats the best way? what i mean is having 2 in an enclosure opens up some possibilites, what would be the suggested scenarios? and how to implement it?

"First, there is the obvious possibility of splitting a mono input signal and having two asynchronous flanger outputs.
Second, there is the possibility of having a mixer and combining the two flanger signals into a single more complex mono output.
Third, there is the possibility of lifting the dry signal from each flanger outputs, and running them "stereo-out" to separate amps or mixer channels.  At slow sweep speeds, this can produce both apparent movement as the phase relationship between left and right keeps changing.  It can also produce "flanging in-air" (though that likely requires standing in the sweet spot).  At faster sweep speeds, you get stereo vibrato, which can be interesting.
Fourth, with dry lift, and setting one of them to "filter matrix" (non-swept) mode, combining flanger A and B gets you variations of through-zero flanging."
Title: Re: EM3207 (v1.1) - MN3207 based EHX Electric Mistress (9V) clone
Post by: Thomeeque on October 03, 2011, 08:33:17 AM
 Hi njkmonty, thanks for the video!! I'm sorry you had troubles with posting longer one, was it too long for youtube? Maybe you could split it into two parts?

is this how tzf be applied ????

 Principally yes, but:

 1. You share same DC bias for both BBDs, so you could have problems to set both for the best performance.

 2. You don't have sufficient filtering (LPFs at in and out), you could have heterodining issues.

 3. EM clock is complicated and limited for this use.

 Consider TZF3207 (http://www.diystompboxes.com/smfforum/index.php?topic=85977.msg720531#msg720531) instead.. I would just maybe add resistors at BBD outs now (like R12 and R13 on EM3207), BBD should be more comfy this way (and you will be closer to EM3207).

 Good luck, T.
Title: Re: EM3207 (v1.1) - MN3207 based EHX Electric Mistress (9V) clone
Post by: Scruffie on October 03, 2011, 08:38:00 AM
Hi njkmonty, thanks for the video!! I'm sorry you had troubles with posting longer one, was it too long for youtube? Maybe you could split it into two parts?

is this how tzf be applied ????

 Principally yes, but:

 1. You share same DC bias for both BBDs, so you could have problems to set both for the best performance.

 2. You don't have sufficient filtering (LPFs at in and out), you could have heterodining issues.

 3. EM clock is complicated and limited for this use.

 Consider TZF3207 (http://www.diystompboxes.com/smfforum/index.php?topic=85977.msg720531#msg720531) instead.. I would just maybe add resistors at BBD outs now (like R12 and R13 on EM3207), BBD should be more comfy this way (and you will be closer to EM3207).

 Good luck, T.
Ooops, didn't check his schematic properly, thought he'd just cut in your TZF module not a copy of the circuit.
Title: Re: EM3207 (v1.1) - MN3207 based EHX Electric Mistress (9V) clone
Post by: Thomeeque on October 03, 2011, 12:05:17 PM
so just build 2 ?

if i do that as mark hammer suggests on first page of this thread, whats the best way? what i mean is having 2 in an enclosure opens up some possibilites, what would be the suggested scenarios? and how to implement it?

"First, there is the obvious possibility of splitting a mono input signal and having two asynchronous flanger outputs.
Second, there is the possibility of having a mixer and combining the two flanger signals into a single more complex mono output.
Third, there is the possibility of lifting the dry signal from each flanger outputs, and running them "stereo-out" to separate amps or mixer channels.  At slow sweep speeds, this can produce both apparent movement as the phase relationship between left and right keeps changing.  It can also produce "flanging in-air" (though that likely requires standing in the sweet spot).  At faster sweep speeds, you get stereo vibrato, which can be interesting.
Fourth, with dry lift, and setting one of them to "filter matrix" (non-swept) mode, combining flanger A and B gets you variations of through-zero flanging."

 For starters build second unit, connect both inputs together and plug each output to one channel in stereo configuration.. then you can build simple mono or stereo mixer where you would mix dry signal and wet signals from both units (each signal with it's own switch or volume pot), this would allow you to try the rest of options.. There could be problem with heterodining, solvable by implementing LPFs into the mixer.. T.
Title: Re: EM3207 (v1.1) - MN3207 based EHX Electric Mistress (9V) clone
Post by: Pdr on October 10, 2011, 05:01:34 PM
Hi there,

I don't have a lot of experience in electronic projects so some doubts appeared in my head.

First of all, I'd find a Deluxe EM project verified on GGG (http://www.generalguitargadgets.com/projects/20-modulationecho/123-deluxe-electric-mistress) and I saw the opportunity of build one for myself, but first I need some informations. I'd like some help to understand the main differences between the deluxe and non-deluxe version because the deluxe version is seriously more complicated, and I don't know if it's worth the effort.
Next, if i decided to build the deluxe, I was considering replacing the sad1024 (and here's the reason why I'm posting here) by MN3207 using the circuit showed in this page - http://img220.imageshack.us/i/sad1024retrofitmn3207lo.jpg/. Here's the source of this link: http://www.diystompboxes.com/smfforum/index.php?topic=78270.60 [page 4, 3rd post].
Is that replacement even possible?

Thanks for everything, this forum is amazing. Sorry for my bad English.

1st post! Hope I didn't break all the rules at once. :)
Title: Re: EM3207 (v1.1) - MN3207 based EHX Electric Mistress (9V) clone
Post by: Thomeeque on October 12, 2011, 05:52:58 AM
 Hi Pdr,

 main difference is different audio path, second (minor) difference is AC/DC (rectifier + filter + 15V regulator) block on-board (in case of DEM). Rest is pretty much same. I would not even say that DEM is "seriously more complicated", what makes it *little* more complicated is this AC/DC block (which you may even omit if you have external 15VDC PSU) and need of use of some kind of retrofit instead of SAD1024 (I would choose MN3007 based retrofit in this case - MN3207 based is not very convenient here as the 15VDC exceeds MN3207 limits).

 So you should IMO choose one you like better from other points of view (sound character, dimensions, ..).

 Note that both EM3x07 and DEM with MN3007 based retrofit will suffer by the same "doubled delay time at same clock frequency" issue, elaborated here a lot.

 Btw. DEMs audio path makes it easier to use TDA1022 based retrofit (which would not suffer by the "doubled delay time at same clock frequency" issue as it is 512 cell BBD) - are you able to get TDA1022 in your area?

 T.
Title: Re: EM3207 (v1.1) - MN3207 based EHX Electric Mistress (9V) clone
Post by: Pdr on October 13, 2011, 04:45:56 PM
Hi T,

When I said that I didn't really know the differences between them, I was talking about the sound character. There are a lot of DEM videos out there, but not EMs (specially clones) . Can someone help me by sending a sound clip of EM clone (preferentially with MN3207)  with some abusive settings? I really wanna see how wacky the sound can get. Or video links that you think that might be useful.

I'm 99% sure that I'll go for the EM because of resources I have to spend on this project. Also, TDA1022 is not available in my area and I believe a 230v-18v transformer inside the pedal would make it much heavier then a stompbox is supposed to be.
The cons list of building the DEM is getting big, and the pcb for the EM with MN3207 is somewhere ready-to-print in this forum so...

Thanks for everything. I'll let you know about my decision and progress in a few days. Any question or problem, I'll ask for help. :)

Pdr



Title: Re: EM3207 (v1.1) - MN3207 based EHX Electric Mistress (9V) clone
Post by: Thomeeque on October 14, 2011, 05:12:52 AM
..and the pcb for the EM with MN3207 is somewhere ready-to-print in this forum so...

 No kidding! :o
Title: Re: EM3207 (v1.1) - MN3207 based EHX Electric Mistress (9V) clone
Post by: Thomeeque on October 14, 2011, 06:08:02 AM
 Actually there is (or will be soon, I have not found project documentation but I may be just badly looking for it) another MN3x07 based EM project:

 madbean's Current Lover (http://www.madbeanpedals.com/forum/index.php?topic=2878.0)

 (http://i232.photobucket.com/albums/ee47/madbeanpedals/current2.jpg)

 Damn strong competitor, I'd say, cool :)

 T.
Title: Re: EM3207 (v1.1) - MN3207 based EHX Electric Mistress (9V) clone
Post by: kranja on January 14, 2012, 10:22:12 AM
I have finally finished my EM MN3207 build  and to my surprise I got a tone (I'm a complete amateur in electronics). The tone that I'm getting isn't quite the tone that I heard on the youtube clips, and I hope the main reason for this is that I need to do the alignment procedure.
I read all the thread and tried to follow the suggestions about the alignment, but somehow find it difficult to follow for someone who have little knowledge about electronics.
I even installed a great software called Visual Analyser (http://www.sillanumsoft.org/download.htm), and I generated a wave and passed it to the EM and back to the soundcard, got the visualization of the wave and got stocked with what to do with the trimpots.
Could someone describe an detailed alignment procedure for complete idiots, eventually with the software I mentioned and some pics or video?

Another problem I'm having is the color pot, which I think is not working at all, because when I turn it it happens absolutely nothing. I tried to play with the RT1 trim but the sound doesn't change at all. The other two knobs work OK, and I'm getting the flange sound. Any suggestions?
Title: Re: EM3207 (v1.1) - MN3207 based EHX Electric Mistress (9V) clone
Post by: Thomeeque on January 16, 2012, 05:18:39 AM
I have finally finished my EM MN3207 build  and to my surprise I got a tone (I'm a complete amateur in electronics). The tone that I'm getting isn't quite the tone that I heard on the youtube clips, and I hope the main reason for this is that I need to do the alignment procedure.
I read all the thread and tried to follow the suggestions about the alignment, but somehow find it difficult to follow for someone who have little knowledge about electronics.
I even installed a great software called Visual Analyser (http://www.sillanumsoft.org/download.htm), and I generated a wave and passed it to the EM and back to the soundcard, got the visualization of the wave and got stocked with what to do with the trimpots.
Could someone describe an detailed alignment procedure for complete idiots, eventually with the software I mentioned and some pics or video?

Another problem I'm having is the color pot, which I think is not working at all, because when I turn it it happens absolutely nothing. I tried to play with the RT1 trim but the sound doesn't change at all. The other two knobs work OK, and I'm getting the flange sound. Any suggestions?

 Hello kranja,

 the fact that you are getting the flange sound means that most parts (LFO, clock, clock buffer, BBD, most of the audio path..) of your unit work correctly and that your RT2 and RT3 are adjusted good enough to get full functionality from 100% healthy build.

 So at this moment don't touch RT2 and RT3 and focus on the COLOR pot issue which indicates that there is something wrong in the audio path (RT1 adjustment does not have fatal influence on this functionality, it's there just for fine-tuning). What comes to my mind first is: did you wire feedback jumper? Then check visually all connections around COLOR pot (pot itself, RT1, C4..). If you don't see nothing obvious make yourself an audioprobe (http://www.diystompboxes.com/wiki/index.php?title=Debugging), set RT1 and COLOR pot to the middle and check signals at top and middle pot lugs and then at pin 5 of the IC1, you should get wet signal there.

 If it does not help, post hi-res pictures of you build (top and bottom of the PCB from few different angles) and maybe sound sample here, we'll see..

 Good luck, T.
Title: Re: EM3207 (v1.1) - MN3207 based EHX Electric Mistress (9V) clone
Post by: mr_deadmaxxx on January 17, 2012, 05:04:25 AM
the video has four pots. your design only has three. what's the pot no.4?
Title: Re: EM3207 (v1.1) - MN3207 based EHX Electric Mistress (9V) clone
Post by: morales72 on January 17, 2012, 05:13:47 AM
Hi to all!

I wasn't sure about posting here or in the MN3007 retrofit since I built this 3207 smaller PCB version adapted to the 3007.
So far it sounds great, swirly, metallic and CLEAN (I build the "bigger" version but was really noisy).
The main issue here is the volume drop when I engage it. I tried changing R5 (3K6) and both R16 and R18 to 8K2. I even put a FET based buffer both at the beginning and the end with no luck.
I use it consistently with my band so it gets annoying when I stomp on it and can't cut through. Any suggestions?

Thanks in advance.

Cheers,

Fernando.
Title: Re: EM3207 (v1.1) - MN3207 based EHX Electric Mistress (9V) clone
Post by: Thomeeque on January 17, 2012, 05:15:02 AM
the video has four pots. your design only has three. what's the pot no.4?

 Current Lover has an additional volume pot (could be handy actually - to get simply similar pot on EM3x07 I would advice to replace R5 by 10~25k pot working as a "gain").

 Btw. there is already CL project file (including schematic) on-line, I hope madbean will not mind direct link here: http://www.madbeanpedals.com/projects/CurrentLover/CurrentLover.pdf (http://www.madbeanpedals.com/projects/CurrentLover/CurrentLover.pdf)

 T.
Title: Re: EM3207 (v1.1) - MN3207 based EHX Electric Mistress (9V) clone
Post by: mr_deadmaxxx on January 17, 2012, 05:34:16 AM
so how do I connect it? as a variable resistor? should I short the middle and one of the outer lugs? Linear or Audio pot?

thanks..
Title: Re: EM3207 (v1.1) - MN3207 based EHX Electric Mistress (9V) clone
Post by: Thomeeque on January 17, 2012, 05:42:58 AM
The main issue here is the volume drop when I engage it. I tried changing R5 (3K6) and both R16 and R18 to 8K2.

 Hi Fernando,

 first: lowering of R16/R18 won't help! These form passive mixer and 1/2 divider for both dry and wet at the same time, at lower value they will still divide the same (not exactly of course as it is complex passive RC network, but principially yes).

 Actually, I would say that replacing R18 by 12k gives better dry/wet ratio (wet path gets boosted by BBD) and may help little bit with volume too.

 Adjusting R5 should help - even with my build I'm considering to add little more gain to the input stage, but drop in my case is really small. Try to replace R5 be 10k trimmer and find the match. If it still won't be enough there is something wrong in your build I would say.

 Another possibility to gain volume is to use output booster as is used in the Current Lover (find link in my previous post) - maybe just use bigger value for C23 (like 1uF), 100n seems little small to me.

 Good luck, T.

so how do I connect it? as a variable resistor?

 Yes, excactly - bigger value = bigger gain.

should I short the middle and one of the outer lugs?

 Well, it won't hurt and you are safer against audible pops caused by wiper momentary loosing contact with the taper.

Linear or Audio pot?

 Experiment. Audio is probably better choice but linear may be OK here as well, range is small (11dB in case of 25k).

thanks..

 You're welcome - just please post your results and remember: pictures and sound samples of finished builds make me happy :)

 Good luck, T.
Title: Re: EM3207 (v1.1) - MN3207 based EHX Electric Mistress (9V) clone
Post by: morales72 on January 17, 2012, 05:55:59 AM
Thanks for the prompt answer T!

I will try those mods. I even checked out the Lover and try the final boost stage too. I'm also considering changing to the MN3207 since I have a couple of them lying around. Maybe it's a voltage related problem? I'll try with 15v to see if it boosts up the volume.
I'm sticking with it though. I love the sound. To me it's even better than the DEM reissue I also have.

Regards,

Fernando.
Title: Re: EM3207 (v1.1) - MN3207 based EHX Electric Mistress (9V) clone
Post by: mr_deadmaxxx on January 17, 2012, 06:00:15 AM
1. Actually, I would say that replacing R18 by 12k gives better dry/wet ratio (wet path gets boosted by BBD) and may help little bit with volume too.

2. Adjusting R5 should help - even with my build I'm considering to add little more gain to the input stage, but drop in my case is really small. Try to replace R5 be 10k trimmer and find the match. If it still won't be enough there is something wrong in your build I would say.

3. Another possibility to gain volume is to use output booster as is used in the Current Lover (find link in the previous post) - maybe just use bigger value for C23 (like 1uF), 100n seems little small to me.

Ok so among these three, which do you think would give the best gain or should I say a good boost for this pedal?
Will replacing R5 with a pot be better than that one in No. 3?

Hmmmm...
Title: Re: EM3207 (v1.1) - MN3207 based EHX Electric Mistress (9V) clone
Post by: Thomeeque on January 18, 2012, 04:15:47 AM
 Start with 1. - better dry/wet ratio is worth trying even if it won't solve volume drop issue.

 Then it depends:

 Increasing gain (2.)

 Booster at the output (3.)

 To make some conclusion:

 If you want to just slightly boost the fx signal to compensate volume drop, you don't get unpleasant distortion and you use simple monophonic signal path (guitar -> pedals -> amp in one simple chain), where phase error does not metter, go for 2.

 In other cases go for booster.

 T.
Title: Re: EM3207 (v1.1) - MN3207 based EHX Electric Mistress (9V) clone
Post by: kranja on January 18, 2012, 09:53:47 AM
I checked all the stuff you mentioned and I found two traces on the pcb touching itself and making a short circuit. After I solved this, everything started to work, the sound is absolutely fantastic!
I would recommend this build to everyone!
Now I still have to figure out the alignment procedure and see if the sound gets even better.
TNX Thomeeque!!!
Title: Re: EM3207 (v1.1) - MN3207 based EHX Electric Mistress (9V) clone
Post by: mr_deadmaxxx on January 18, 2012, 12:28:42 PM
Okay. I was thinking of no. 3..
Anyways, if I use no. 3, why use 1uF instead of 100nF? Can 1uF be polarized?

BTW, can I use electrolytic capacitors instead of tantal/tantalum capacitors specified on your builds? What would be the difference?

Thanks..
Title: Re: EM3207 (v1.1) - MN3207 based EHX Electric Mistress (9V) clone
Post by: mr_deadmaxxx on January 18, 2012, 12:31:29 PM
What's the alignment procedure?
Title: Re: EM3207 (v1.1) - MN3207 based EHX Electric Mistress (9V) clone
Post by: morales72 on January 18, 2012, 08:07:00 PM
Hi to all!

I had a late night Mistress session after rehearsal and I tried the first two options.

1 - 12K R18: Matched bypass volume but to my ears was too dry and had to crank feedback badly to hear the effect.

2 - 10K trim: did the job all the way up so I replaced with a 12K (don't have 10Ks lying around) and did the trick. Again I can hear the watery effect and with matched volume to bypass.

I will try next Friday with the band to see if it cuts through!

Here are some pics of the building. Forgive my "Back to the future" Dymo style, I was a teenager in the 80's...

(http://img214.imageshack.us/img214/336/img8960o.jpg) (http://imageshack.us/photo/my-images/214/img8960o.jpg/)

Uploaded with ImageShack.us (http://imageshack.us)

(http://img688.imageshack.us/img688/3791/img8958jv.jpg) (http://imageshack.us/photo/my-images/688/img8958jv.jpg/)

Uploaded with ImageShack.us (http://imageshack.us)

(http://img338.imageshack.us/img338/29/img8953w.jpg) (http://imageshack.us/photo/my-images/338/img8953w.jpg/)

Uploaded with ImageShack.us (http://imageshack.us)

I'm usually not this messy but it got out of control at some point.

Cheers!

Fernando.
Title: Re: EM3207 (v1.1) - MN3207 based EHX Electric Mistress (9V) clone
Post by: Thomeeque on January 19, 2012, 04:34:53 AM
I checked all the stuff you mentioned and I found two traces on the pcb touching itself and making a short circuit. After I solved this, everything started to work, the sound is absolutely fantastic!
I would recommend this build to everyone!
Now I still have to figure out the alignment procedure and see if the sound gets even better.
TNX Thomeeque!!!

 Hey kranja, that's great news - congratulations! :)

 I'll try to write proper alignment procedure later, you may wait or try to do your own research meanwhile, there's lot of info on-line :)

Okay. I was thinking of no. 3..
Anyways, if I use no. 3, why use 1uF instead of 100nF?

 100nF may cut low frequencies too much (exact behavior will depend on the volume pot position and load at the output; if you want to know more learn how to use LTSpice, there are tutorials on-line like http://gaussmarkov.net/wordpress/tools/software/ltspice/ltspice-ac-analysis-with-the-bmp-tone-stack/ (http://gaussmarkov.net/wordpress/tools/software/ltspice/ltspice-ac-analysis-with-the-bmp-tone-stack/)). But maybe that's the point, you can simply try both options.

Can 1uF be polarized?

 Yes, plus at the Q3 collector.

BTW, can I use electrolytic capacitors instead of tantal/tantalum capacitors specified on your builds?

 Yes, no problem, original uses electrolytics IIRC..

What would be the difference?

 I prefer to use tantalum mainly in LFOs and "around" LFOs as they should be more stable, should have lower parasitic resistance and they should last longer. But it's nothing critical, if sourcing was problem I'd calmly go with electrolytics. More about electrolytic vs. tantalum e.g. here (http://www.diystompboxes.com/smfforum/index.php?topic=30450.0).

Hi to all!

I had a late night Mistress session after rehearsal and I tried the first two options.

1 - 12K R18: Matched bypass volume but to my ears was too dry and had to crank feedback badly to hear the effect.

2 - 10K trim: did the job all the way up so I replaced with a 12K (don't have 10Ks lying around) and did the trick. Again I can hear the watery effect and with matched volume to bypass.

 Hm, it makes me wonder if the MN3007 does not make the difference here - I had never used it in my EM3207, all my experiences and measurements are based on the use of MN3207.

 Nevertheless I'd check whole audio path by measuring dry and wet signals:


 all measured AC voltages should be at least 0.2V * R3/(R2+R3) * (1 + R5/R4).

I will try next Friday with the band to see if it cuts through!

 Please, let us know then.

Here are some pics of the building. Forgive my "Back to the future" Dymo style, I was a teenager in the 80's...

 Thanks! I love it (maybe because I was a teenager in the 80's too :))!

I'm usually not this messy but it got out of control at some point.

 No problem, it gives it cool organic feel ;) T.
Title: Re: EM3207 (v1.1) - MN3207 based EHX Electric Mistress (9V) clone
Post by: mr_deadmaxxx on January 19, 2012, 01:46:09 PM
 :)
Title: Re: EM3207 (v1.1) - MN3207 based EHX Electric Mistress (9V) clone
Post by: mr_deadmaxxx on January 22, 2012, 02:07:25 PM
how do I adjust the trim pots?which should I bias first?
what does increasing the 2n2 feedback cap do?should I say I parallel it with a 3n3?will I get the airplane flanging with this?
is it really necessary to add the six 100nf filtering capacitors for the IC's?
Title: Re: EM3207 (v1.1) - MN3207 based EHX Electric Mistress (9V) clone
Post by: morales72 on January 22, 2012, 09:35:23 PM
Hi to all!

I finally tried it with the band this weekend and it worked great! Actually it inspired me in some The Cure like guitar lines (will try to upload later a bit of it since it was a long collective improv).

Thank you again T! Your work has been truly inspiring to me!

Regards,

Fernando.
Title: Re: EM3207 (v1.1) - MN3207 based EHX Electric Mistress (9V) clone
Post by: Thomeeque on January 23, 2012, 04:32:20 PM
Hi to all!

I finally tried it with the band this weekend and it worked great! Actually it inspired me in some The Cure like guitar lines (will try to upload later a bit of it since it was a long collective improv).

Thank you again T! Your work has been truly inspiring to me!

Regards,

Fernando.

 My pleasure, I'm really glad you like it! I'm looking forward to hear your samples :) Cheers, T.
Title: Re: EM3207 (v1.1) - MN3207 based EHX Electric Mistress (9V) clone
Post by: mr_deadmaxxx on January 24, 2012, 01:45:14 AM
how do I adjust the trim pots?which should I bias first?
what does increasing the 2n2 feedback cap do?should I say I parallel it with a 3n3?will I get the airplane flanging with this?
is it really necessary to add the six 100nf filtering capacitors for the IC's?

can I substitute the 2N5087 with a 2n3906?
Title: Re: EM3207 (v1.1) - MN3207 based EHX Electric Mistress (9V) clone
Post by: Thomeeque on January 26, 2012, 10:47:23 AM
how do I adjust the trim pots?which should I bias first?

 This is exactly what "alignment procedure" is about, which I'm still too busy (or too lazy) to describe. But this is the Electric Mistress clone and there are zillions of guides how to align EM on-line, start e.g. here (http://www.metzgerralf.de/elekt/stomp/mistress/align.shtml).

 RT1 = FEEDBACK trim
 RT2 = BIAS trim
 RT3 = CLOCK trim

 One hint: start with BIAS. Rough MN3207's DC bias (DC voltage measured at input pin 3) should be:

 VBIAS = 0.42 + 0.54*VCC [V]

 (approximation of VBIAS -- VDD graph from MN3207 datasheet).

 Set this value and fine-tune later (following align guides).

what does increasing the 2n2 feedback cap do?should I say I parallel it with a 3n3?will I get the airplane flanging with this?

 I doubt it, it will just have slightly different color - build it and try it.

is it really necessary to add the six 100nf filtering capacitors for the IC's?

 No.

can I substitute the 2N5087 with a 2n3906?

 Yes, but you may get slightly different sweep character (my advice is to stay as close as possible with parts around clock VCO = around Q2, IC4), on the other hand it shouldn't be fatal.

 Btw. I won't answer any more questions if "thanks" and "please" keywords will be missing, this is not some sort of prepaid support service. When you are asking for favor you have to show respect.

 T.
Title: Re: EM3207 (v1.1) - MN3207 based EHX Electric Mistress (9V) clone
Post by: 12Bass on January 26, 2012, 09:21:31 PM
Thanks Thomeeque. 

No questions.... just thanks...   :D
Title: Re: EM3207 (v1.1) - MN3207 based EHX Electric Mistress (9V) clone
Post by: oldschoolanalog on January 26, 2012, 09:59:38 PM
Thanks Thomeeque. 
No questions.... just thanks...   :D
Amen. +1 ;D.
Thanks!
And please too!
Just want to pay some gratitude forward...
Title: Re: EM3207 (v1.1) - MN3207 based EHX Electric Mistress (9V) clone
Post by: sugonidamaso on January 26, 2012, 11:45:15 PM
Amen T! Thank you very much! Most especially your dedication to this forum! And yes " Please" too! ;D ;D ;D
Title: Re: EM3207 (v1.1) - MN3207 based EHX Electric Mistress (9V) clone
Post by: Thomeeque on January 27, 2012, 04:17:06 AM
Alright alright alright, it was meant for Don, but whatever :icon_mrgreen: You're welcome guys, my pleasure, amen :) T.
Title: Re: EM3207 (v1.1) - MN3207 based EHX Electric Mistress (9V) clone
Post by: mr_deadmaxxx on January 27, 2012, 09:47:25 AM
Awts. My bad. Thanks... :D

Finally done building this and it worked right away I didn't even have to debug it. Though I substituted 2N5087 with another transistor, and even without the filter caps, I still got the flanging sound. Though the color pot starts to oscillate at midway up to fully clockwise and I can't seem to tell the difference of what the range pot can do. I just biased the parts by ear but I will try to bias this later following the above instructions.

And I apologize I forgot to say thanks. Will post photos once it's done.
Thanks.
Title: Re: EM3207 (v1.1) - MN3207 based EHX Electric Mistress (9V) clone
Post by: Thomeeque on January 27, 2012, 01:49:55 PM
 Great, congrats! Apology accepted, looking forward for pics :) Cheers, T.
Title: Re: EM3207 (v1.1) - MN3207 based EHX Electric Mistress (9V) clone
Post by: mr_deadmaxxx on January 28, 2012, 10:57:53 AM
This is what I can post for now. Crappy camera on a crappy phone.
Will post more once it's completely done. The fourth knob is a Gain knob replacing R5.

(http://img806.imageshack.us/img806/5443/2801122112.jpg) (http://imageshack.us/photo/my-images/806/2801122112.jpg/)

Uploaded with ImageShack.us (http://imageshack.us)
Title: Re: EM3207 (v1.1) - MN3207 based EHX Electric Mistress (9V) clone
Post by: Thomeeque on January 30, 2012, 06:03:45 AM
This is what I can post for now. Crappy camera on a crappy phone.

 Thanks anyway :)

..The fourth knob is a Gain knob replacing R5...

 So, how does it work for you? Would you be able to measure value where you feel like it's in unity gain compared to bypass?

 Cheers, T.
Title: Re: EM3207 (v1.1) - MN3207 based EHX Electric Mistress (9V) clone
Post by: Morocotopo on February 09, 2012, 09:33:14 AM
Hi.

First things first: Thanks so much Thomas for the work you did and generously shared with us.

I built the MN3007 version from your files. Regarding your PCB:
- Man, you like to live in danger, don´t you? :) The jumper that goes between IC3´s legs is, hmm, a bold move! I actually made the jumper go around and "enter" below the chip from the top, not between legs. Seemed more safe to me.
- Some wires holes are very close to other parts, a bit difficult to get them in.
- The speed pot wiring left me a bit confused, I wondered why my LFO didn´t change speed ´till I looked at the PCB connections, was a little confused by a pic you posted. But an easy fix.
- In the layout file, the 3904 is reversed, should be the other way around.
- I actually modded your PCB, made the tracks thinner in places. Seemed to me that in some spots there were dangers of tracks bleeding into each other if you etched them with the iron a bit too hot.

About the build, I did some replacements:
- 2N5087 replaced with a BC559B. I tested the Hfe and it was around 430, so in spec with the 5087 Hfe range. A BC559C would be better, maybe. I think, as long as the transistor is in the original one´s Hfe range, it will work. Watch the pinouts!
- Some R´s: 30K for 33K, 14K for 15K
- The 4049 is a buffered one (4049B)
- For the Zener I used a 12V 1W one.
- For the 220 uF caps, the only ones that fit are 16V ones. 25V ones are too large to fit! Another trip to the store...

It works, flanges good. I´ve never heard an original, so I can´t compare sounds, but it´s nice as it is. Without the 100n caps to filter the chip´s power and with the thing lying on my desk, I get no ticking. Shielded input wire, though, just in case.  Well, now I´m gonna reread the thread to see if there´s any improvements to be made. I recall some
discussion about max clock frequency from my earlier read...

All in all, a good, nice, musical flanger. I made a 301 from tonepad´s site and, although I haven´t compared them side to side, this, in first impressions, is nicer.  If wanted, I can make sound samples/take measurements, whatever it´s needed. Tell me.

Thanks again Thomas!

P.D: Am I the first one to build the 3007 one on your PCB?
Title: Re: EM3207 (v1.1) - MN3207 based EHX Electric Mistress (9V) clone
Post by: Thomeeque on February 09, 2012, 10:42:21 AM
Hi.

First things first: Thanks so much Thomas for the work you did and generously shared with us.

 Hi, my pleasure, thanks for the report! :)

I built the MN3007 version from your files. Regarding your PCB:
- Man, you like to live in danger, don´t you? :) The jumper that goes between IC3´s legs is, hmm, a bold move! I actually made the jumper go around and "enter" below the chip from the top, not between legs. Seemed more safe to me.

 I use it often (http://thmq.mysteria.cz/em1022/detail.htm?3), with properly shaped insulated solid core wire you are IMO safe.

- Some wires holes are very close to other parts, a bit difficult to get them in.

 Bit difficult - OK, but you made it, right? ;) IMO small price for compact layout.

- The speed pot wiring left me a bit confused, I wondered why my LFO didn´t change speed ´till I looked at the PCB connections, was a little confused by a pic you posted. But an easy fix.

 Too sexy to read build instructions, huh? ;)

- In the layout file, the 3904 is reversed, should be the other way around.

 Oh, good catch, you're right - I've got or made wrong eagle symbol once and it still pops up time to time - thanks!

- I actually modded your PCB, made the tracks thinner in places. Seemed to me that in some spots there were dangers of tracks bleeding into each other if you etched them with the iron a bit too hot.

 OK, I like'em fat ;) And it can be advantage for toner transfer method too - at least my experiments with this method led to not very solid traces (as the toner did not cover 100%-ly) with lot of micro-holes which could even interrupt thin traces - but it may be just my hands.

 One way or another I advice to carefully check PCB traces before soldering in build notes.

About the build, I did some replacements:
- 2N5087 replaced with a BC559B. I tested the Hfe and it was around 430, so in spec with the 5087 Hfe range. A BC559C would be better, maybe. I think, as long as the transistor is in the original one´s Hfe range, it will work. Watch the pinouts!
- Some R´s: 30K for 33K, 14K for 15K
- The 4049 is a buffered one (4049B)

 Not replacement actually, buffered logic chips are listed in the part list.

- For the Zener I used a 12V 1W one.
- For the 220 uF caps, the only ones that fit are 16V ones. 25V ones are too large to fit! Another trip to the store...

 Again, price for the compact layout.

It works, flanges good. I´ve never heard an original, so I can´t compare sounds, but it´s nice as it is. Without the 100n caps to filter the chip´s power and with the thing lying on my desk, I get no ticking. Shielded input wire, though, just in case.  Well, now I´m gonna reread the thread to see if there´s any improvements to be made.

 My advice would be to go thru the thread before the build, but.. :)

I recall some discussion about max clock frequency from my earlier read...

All in all, a good, nice, musical flanger. I made a 301 from tonepad´s site and, although I haven´t compared them side to side, this, in first impressions, is nicer.  If wanted, I can make sound samples/take measurements, whatever it´s needed. Tell me.

Thanks again Thomas!

P.D: Am I the first one to build the 3007 one on your PCB?

 Again, you are welcome, I'm glad you like the sound and as you probably really are the first one who at least admitted it here, I'd really appreciate sound samples and photos of your build!

 Cheers, T.
Title: Re: EM3207 (v1.1) - MN3207 based EHX Electric Mistress (9V) clone
Post by: Morocotopo on February 09, 2012, 12:14:56 PM
Errata:

It´s Tomas, not Thomas...  Repeat after me: Tomas, Tomas, Tomas...

Sorry about that!

Of course, most things I commented are what allow for a really small PCB, wich I think it´s great, I hate big pedals. I confess guilty of not reading thoroughly the build instructions...

After rereading the thread, I´ll try the 250K range pot and/or the 1K R34, to see what effect they have. I´ll take some measurements and do some audio samples, sure, no problem. As to the photos, I only have a crap cell phone camera, but I´ll see what I can do with that.
Title: Re: EM3207 (v1.1) - MN3207 based EHX Electric Mistress (9V) clone
Post by: Morocotopo on February 09, 2012, 01:18:07 PM
OK, pictures:

(http://i68.photobucket.com/albums/i5/Morocotuco/EH-EM-2007-16.jpg)
(http://i68.photobucket.com/albums/i5/Morocotuco/EH-EM-2007-6.jpg)

Audio:

http://soundcloud.com/truemostro/eh-em-3007/s-g8s6I

P90 guitar>EM>computer. First at various settings, then in filter matrix mode playing with the range pot. The recording is a little saturated, not the circuit. Later I´ll take some measurements and do the mods posted earlier.
Title: Re: EM3207 (v1.1) - MN3207 based EHX Electric Mistress (9V) clone
Post by: JRM on February 13, 2012, 10:01:06 AM
Hi,

I've just found this thread a couple of days ago when I was setting up the trimpots of my EM retrofitted with a MN3207. And after reading through it I'm a little bit confused: I thought that with the retrofit we'll be able to reach the same performance as with the SAD1024 (overclocking the 3207 to overcome the 512 vs 1024 stages, etc.) but after reading the first pages it seems that we don't, as the MN3207 can't deliever the same delay.
I'm not an expert at all, just a guy that likes diy, knows how to solder, use a multimeter and what an IC, a trannie, a resitor or a capacitor are, so:
Can someone PLEASE explain me if there's anything that I can/have to do get the sound of my EM clone as near as possible to the original (that I don't have/can't afford)?

P.S: In the beggining of my building project I have found a SAD1024 in a local shop for a very expensive €50! Maybe I should have bought it...
Title: Re: EM3207 (v1.1) - MN3207 based EHX Electric Mistress (9V) clone
Post by: jdub on February 27, 2012, 06:01:41 PM
@JRM: Having tried both a 1024 and the mn3007 daughterboard retrofit in my EM, it seemed to me that with proper adjustment the 3007 version comes mighty close to the 1024.  However, I've never owned an original, so I can't say how close either of mine came to it...my impression, though, is that the 3007 retrofit does capture the character of the effect; as always, though, YMMV.  Sorry to not be much help with that one... :icon_redface:

@Tomas: Thanks so much for this project, and all your others.  They've provided me with hours of fun and education.  Hats off to you, sir!

I do have a quick question about the EM3007 board, though, and apologize if it's a foolish one: What, exactly, are the purposes of pads 1 (in ground), 4 (out ground) and 10 & 11 (CC)?  Pads 1 & 4 already appear to be connected to circuit ground, so I'm puzzled, and while I know what Vcc is, CC is a new one for me.  I haven't run across these designations in other builds.  Can they be left unconnected?  Anyone?  Thanks!
Title: Re: EM3207 (v1.1) - MN3207 based EHX Electric Mistress (9V) clone
Post by: 12Bass on February 27, 2012, 06:38:44 PM
@JRM: Having tried both a 1024 and the mn3007 daughterboard retrofit in my EM, it seemed to me that with proper adjustment the 3007 version comes mighty close to the 1024.  However, I've never owned an original, so I can't say how close either of mine came to it...my impression, though, is that the 3007 retrofit does capture the character of the effect; as always, though, YMMV.

Have you noticed any difference in fidelity or high frequency response?  From what I understand, the SAD1024A is capable of much more extended high frequency response (>10 kHz) than the MN3007.  However, given that a lot of flangers employ low pass filtering, this may not be that audible in practice.  I've relaxed the filtering on my A/DA build and a delay path using the Reticon chip can definitely sound very clear if fed a full-range signal.
Title: Re: EM3207 (v1.1) - MN3207 based EHX Electric Mistress (9V) clone
Post by: jdub on February 27, 2012, 07:41:18 PM
[quoteHowever, given that a lot of flangers employ low pass filtering, this may not be that audible in practice.][/quote]

I think this is the case.  I guess it depends on application: I didn't do a detailed comparison, as I don't own a scope, I just adjusted them on the bench and used them both at different times in a live setting, and to my ears they both had the same character- which admittedly is a subjective perception.  Of course, with the dueling frequencies bouncing around a live gig, it's tough to really zero in on the differences in high-frequency response between the two  ;D  In a controlled setting, though, I  think the SAD would certainly trump the 3007.  For me, though, the whole point is to be able to nail the vibe of the Mistress with a $10 chip as opposed to a $50+ chip, and the 3007 versions I think succeed admirably. 
Title: Re: EM3207 (v1.1) - MN3207 based EHX Electric Mistress (9V) clone
Post by: mr_deadmaxxx on February 27, 2012, 10:06:00 PM
clear photos.. :)

(http://img853.imageshack.us/img853/8876/img1016dp.jpg) (http://imageshack.us/photo/my-images/853/img1016dp.jpg/)

(http://img812.imageshack.us/img812/6821/img1013jp.jpg) (http://imageshack.us/photo/my-images/812/img1013jp.jpg/)

(http://img109.imageshack.us/img109/4143/img1014vf.jpg) (http://imageshack.us/photo/my-images/109/img1014vf.jpg/)


many thanks to T..
Title: Re: EM3207 (v1.1) - MN3207 based EHX Electric Mistress (9V) clone
Post by: 12Bass on February 28, 2012, 05:51:42 AM
I think this is the case.  I guess it depends on application: I didn't do a detailed comparison, as I don't own a scope, I just adjusted them on the bench and used them both at different times in a live setting, and to my ears they both had the same character- which admittedly is a subjective perception.  Of course, with the dueling frequencies bouncing around a live gig, it's tough to really zero in on the differences in high-frequency response between the two  ;D  In a controlled setting, though, I  think the SAD would certainly trump the 3007.  For me, though, the whole point is to be able to nail the vibe of the Mistress with a $10 chip as opposed to a $50+ chip, and the 3007 versions I think succeed admirably.

Thanks.

Sure... I wouldn't recommend using the SAD chips in a new build unless people already have one on hand.  I have a few MN3007s around and some time ago tried an MN3007 daughterboard with my SAD1024A A/DA.  In a brief test I heard output, but the sound was weak.  Didn't spend much time trying to fine tune the board for the new chip, so I'm not sure what to conclude.  I'm somewhat curious about using the MN3007 because they are supposed to have more headroom than the Reticon BBDs; my basses sometimes cause clipping in the BBD. 
Title: Re: EM3207 (v1.1) - MN3207 based EHX Electric Mistress (9V) clone
Post by: jdub on February 29, 2012, 09:00:49 AM
Quote
I do have a quick question about the EM3007 board, though, and apologize if it's a foolish one: What, exactly, are the purposes of pads 1 (in ground), 4 (out ground) and 10 & 11 (CC)?  Pads 1 & 4 already appear to be connected to circuit ground, so I'm puzzled, and while I know what Vcc is, CC is a new one for me.  I haven't run across these designations in other builds.  Can they be left unconnected?  Anyone?  Thanks!

Bump?  :icon_redface:
Title: Re: EM3207 (v1.1) - MN3207 based EHX Electric Mistress (9V) clone
Post by: oldschoolanalog on February 29, 2012, 09:16:36 AM
Confusion. Ugh!
Title: Re: EM3207 (v1.1) - MN3207 based EHX Electric Mistress (9V) clone
Post by: Thomeeque on February 29, 2012, 09:18:25 AM
 pads 1 (in ground), 4 (out ground) - you may want to use shielded wire for in & out, these pads can be used to ground it's shield

 pads 10 & 11 (CC) - build instructions, ADVICED MODS chapter, third bullet

 Good luck, T.

 EDIT:

 @John: be careful about reversed Q1 (2N3904) layout on EM3007_v1.1_values_1200DPI.png and EM3007_v1.1_names_1200DPI.png, "belly" should go down not up..

 @all: Btw. thanks for all your posts, photos, samples, discussion, etc. I appreciate it, I just don't have time to answer properly :)
Title: Re: EM3207 (v1.1) - MN3207 based EHX Electric Mistress (9V) clone
Post by: jdub on February 29, 2012, 11:59:26 AM
Thank you, Tomas.  Not sure how I missed the CC thing, since I've read over the build notes half a dozen times.  Argh!  Sorry to bother you with that... ::) As for the input and output grounds, I suspected something like that but wanted to be sure.   Thanks again.

PS.  Apparently I missed the post in this enormous thread about the reversed 3904 (found it after the fact)...my fault really, I normally check transistor pinouts against the schem before soldering...but oh well, easily fixed...!   ;)
Title: Re: EM3207 (v1.1) - MN3207 based EHX Electric Mistress (9V) clone
Post by: Thomeeque on March 02, 2012, 06:15:05 AM
Thank you, Tomas.  Not sure how I missed the CC thing, since I've read over the build notes half a dozen times.  Argh!  Sorry to bother you with that... ::) As for the input and output grounds, I suspected something like that but wanted to be sure.   Thanks again.

 No problem, you're welcome.

PS.  Apparently I missed the post in this enormous thread about the reversed 3904 (found it after the fact)...my fault really, I normally check transistor pinouts against the schem before soldering...but oh well, easily fixed...!   ;)

 Yep, that's easy to be missed - I have updated original layouts with warning for the future builders :)

 T.
Title: Re: EM3207 (v1.1) - MN3207 based EHX Electric Mistress (9V) clone
Post by: nordine on March 22, 2012, 04:52:48 AM
HOT DAMN!

First of all, i have to thank Tomas because of his incredible efforts sharing this amazing circuit, you're truly a bro  :icon_mrgreen:

Did MN3207 version,

Layout is so nice i had a blast populating the board, and guess what.... i needed only 5 minutes of debugging till this bad boy was running out of control... sounds so sweet, i had The Wall era Pink Floyd tones .... even Brixton Academy Faith no More's Bass flanging (cause im a bassman)

now, im curious about the trimpots

a) theres the 100k one, it regulates vref ...now, in every position it "sounds good" i just hear increments on volume ...whats the ideal voltage it should give off? 4.5?

b) color one, 10k trimpot.... it regulates the amount of feedback... i really like the metallic sound, but as said above, it turns into self oscillation pretty fast... id like to mantain the metallic timbre without getting into wailing area, is it possible?

c) this one is fun, 22k @ clock driver(?) ...used 50k anyways.... its kind of an offset control... i like it....now, if i turn it almost full to the left, i get more high offset, nearly sounding like TZF... but when its getting really there... it cuts abruptly the flanging, with a little "pop"... something like woooshhhhhhhh-pop-silence-pop-shhhhoooooo...... its like it falls out and deactivates... how to make it sound smooth?

well lots of questions, but this circuits really got me interested, good work!
will follow with pics and samples, cheers!

edit: toying more with the flanger, i got to clearly distinct clock noise... one thats too high in some settings to be usable..... its no oscillation, its clock noise, a digital(aliased?) kind of wooshing... like heterodyning.... somewhere i read that a proper way to cancel clock noise was to pick the two outs of the delay chip (in this case MN3207) and put a trimpot there ...so this could be replacing R12 and R13 for one 10k trimpot and tweaking it...... could it work??
Title: Re: EM3207 (v1.1) - MN3207 based EHX Electric Mistress (9V) clone
Post by: Thomeeque on March 23, 2012, 05:52:20 AM
HOT DAMN!

First of all, i have to thank Tomas because of his incredible efforts sharing this amazing circuit, you're truly a bro  :icon_mrgreen:

Did MN3207 version,

Layout is so nice i had a blast populating the board, and guess what.... i needed only 5 minutes of debugging till this bad boy was running out of control... sounds so sweet, i had The Wall era Pink Floyd tones .... even Brixton Academy Faith no More's Bass flanging (cause im a bassman)

 Hello, congrats, I'm glad you like the result :)

now, im curious about the trimpots

a) theres the 100k one, it regulates vref ...now, in every position it "sounds good" i just hear increments on volume ...whats the ideal voltage it should give off? 4.5?

 Hmm, if it sounds good in every position then there is something wrong actually - are you sure you get flanging in it's whole range? Primary goal of RT2 is to adjust proper bias voltage for BBD chip and there is relatively thin area where is BBD biased properly (that's why I advice to use precise multi-turn type of trimmer here btw.), when misbiased it distorts passing signal or it does not pass signal at all..

 For more about RT2 read this post (http://www.diystompboxes.com/smfforum/index.php?topic=91981.msg830595#msg830595) (Reply #245) or this one (http://www.diystompboxes.com/smfforum/index.php?topic=91981.msg804532#msg804532) (Reply #131).

b) color one, 10k trimpot.... it regulates the amount of feedback... i really like the metallic sound, but as said above, it turns into self oscillation pretty fast... id like to mantain the metallic timbre without getting into wailing area, is it possible?

 Set COLOR pot to max and adjust RT1 before self-oscillation starts (or to any point you want your maximum of "color" to be).

c) this one is fun, 22k @ clock driver(?) ...used 50k anyways.... its kind of an offset control... i like it....now, if i turn it almost full to the left, i get more high offset, nearly sounding like TZF... but when its getting really there... it cuts abruptly the flanging, with a little "pop"... something like woooshhhhhhhh-pop-silence-pop-shhhhoooooo...... its like it falls out and deactivates... how to make it sound smooth?

 Frequency range of the clock is not infinite, at "pop" you reach it's maximum where clock stops. For more read "*" note in this post (http://www.diystompboxes.com/smfforum/index.php?topic=91981.msg802217#msg802217) (Reply #94).

well lots of questions, but this circuits really got me interested, good work!
will follow with pics and samples, cheers!

 Looking forward to see&hear it :)

edit: toying more with the flanger, i got to clearly distinct clock noise... one thats too high in some settings to be usable..... its no oscillation, its clock noise, a digital(aliased?) kind of wooshing... like heterodyning.... somewhere i read that a proper way to cancel clock noise was to pick the two outs of the delay chip (in this case MN3207) and put a trimpot there ...so this could be replacing R12 and R13 for one 10k trimpot and tweaking it...... could it work??

 Maybe, it depends.. Describe your whole signal chain between guitar and amp (other effects, some digital or BBD based ones maybe?) and what PSU do you use (I know about one Mistress having similar issues with 1SPOT)..

 T.
Title: Re: EM3207 (v1.1) - MN3207 based EHX Electric Mistress (9V) clone
Post by: nordine on March 23, 2012, 07:44:44 PM
I will try again that 100k trimpot, now that i remember, i set it when i had only the 4558 on board....maybe i biased it well just by accident, cause i dont hear any distortion in flanging

guitar is direct to effect, psu is transformer using hard filtering and 9v regulator

heres the video:



*rate pot is busted btw, needs changing
Title: Re: EM3207 (v1.1) - MN3207 based EHX Electric Mistress (9V) clone
Post by: Thomeeque on March 26, 2012, 10:45:23 AM
I will try again that 100k trimpot, now that i remember, i set it when i had only the 4558 on board....

 Oh, in that case there was not much happening until you did reach one of the borders.

maybe i biased it well just by accident, cause i dont hear any distortion in flanging

 You probably did. Distortion depends on input signal amplitude as well, well biased BBD gives you biggest dynamic range before distortion starts.

guitar is direct to effect, psu is transformer using hard filtering and 9v regulator

 Hm, you may be picking something from the air then (even there is AM filter at the input it is not absolute).. maybe post audio sample of the heterodining you are getting.

 Anyway, trying to balance BBD outs for minimal clock noise may be interesting and valuable experiment, so if you don't mind to resolder it little for a while, please go ahead and try it.

heres the video:

 Sounds really good :) Very effective demo you have made (showing swiftly whole range of basic sounds), I like it! :)

 Cheers, T.
Title: Re: EM3207 (v1.1) - MN3207 based EHX Electric Mistress (9V) clone
Post by: nordine on March 28, 2012, 06:36:42 AM
Thanks!

Well, i messed again with the bias trimmer and, since its multiturn, it takes a lots of turns to "fall out of bias", and there i heard distortion and no flanging... but anyways, it works as suppossed

will do the balance thing in my next EM, this one is eager to be played with  :icon_mrgreen:

while boxing it, and after listening to a youtube demo of an old electric misstress (vertical box, green letters), i saw that it has HUGE range... unlike this one (EM9v)... so then i put a 250k pot instead of the 100k it has... the range was maximized, but it got "bird chirping", clock issues i think? much like john holli's ultraflanger (a good flanger but plagued with noises that rendered it useless)... any ideas on how to expand range without getting the "chirp"? ...will post samples of all the noises im talking about, cheers!
Title: Re: EM3207 (v1.1) - MN3207 based EHX Electric Mistress (9V) clone
Post by: Thomeeque on March 29, 2012, 09:35:06 AM
Thanks!

Well, i messed again with the bias trimmer and, since its multiturn, it takes a lots of turns to "fall out of bias", and there i heard distortion and no flanging... but anyways, it works as suppossed

 When adjusting BBD bias "properly" using sinus signal generator at the input and oscilloscope at the BBD output you'd find that there is basically one sweet spot (even this sweet spot actually moves little bit with the clock frequency so the chosen value is sort of compromise anyway) and that you loose it rapidly during small fragment of one turn of the bias multi-turn trimmer. On the other hand it is adjusted for relatively big input signal amplitude and with guitar you are usually significantly lower (with bass it may be different) and mainly: you probably don't mind little bit of distortion there (it just affects wet path, clear signal is still clear) anyway, it may be even interesting (we are not hi-fi purists here, quite opposite :)).

will do the balance thing in my next EM, this one is eager to be played with  :icon_mrgreen:

 :)

while boxing it, and after listening to a youtube demo of an old electric misstress (vertical box, green letters), i saw that it has HUGE range... unlike this one (EM9v)...

 This (http://www.youtube.com/watch?v=4XqEeJbHcXg&t=4m28s) demo by any chance? :)

 This old EM had very different clock circuitry (including the way it's frequency is swept). When I saw this demo for the first time I was surprised by it's HUGE range too and I was getting bit jealous, but later I did realize that extended range moves it mostly to the areas where it sounds already too crazy and unpleasant for my ears and that I'm quite happy with EM9V range (maybe just placebo but it works ;)).

so then i put a 250k pot instead of the 100k it has... the range was maximized, but it got "bird chirping", clock issues i think? much like john holli's ultraflanger (a good flanger but plagued with noises that rendered it useless)... any ideas on how to expand range without getting the "chirp"? ...will post samples of all the noises im talking about, cheers!

 If it's caused by the clock you cannot fix it by different way of clock range expansion unless you would move the range away from critical frequency. Definitely post sample first, "chirp" is too abstract for me ;).

 T.
Title: Re: EM3207 (v1.1) - MN3207 based EHX Electric Mistress (9V) clone
Post by: 12Bass on March 29, 2012, 06:53:29 PM
When adjusting BBD bias "properly" using sinus signal generator at the input and oscilloscope at the BBD output you'd find that there is basically one sweet spot (even this sweet spot actually moves little bit with the clock frequency so the chosen value is sort of compromise anyway) and that you loose it rapidly during small fragment of one turn of the bias multi-turn trimmer. On the other hand it is adjusted for relatively big input signal amplitude and with guitar you are usually significantly lower (with bass it may be different) and mainly: you probably don't mind little bit of distortion there (it just affects wet path, clear signal is still clear) anyway, it may be even interesting (we are not hi-fi purists here, quite opposite :)).

Hmmm... I might be a bit of an exception.  Though I use effects with bass more than guitar.  A clipped BBD does not sound very pleasant with bass, so I try to set the BBD bias as optimally as possible to maximize clean headroom.  What you say above is true - the bias voltage "sweet spot" varies slightly with clock frequency, so a "happy medium" must be chosen.  At a given clock frequency, however, the lowest distortion occurs at a very narrow point in the adjustment range.  What I do is send the circuit a sine wave (say 100 Hz) and keep increasing the amplitude and readjusting the bias until the maximum amount of clean signal through the BBD has been attained.
Title: Re: EM3207 (v1.1) - MN3207 based EHX Electric Mistress (9V) clone
Post by: ricbox on June 10, 2012, 07:04:24 AM
Got a question for the EM3007 version: what kind of switch do I have to wire up for the Filter? 3PDT? SPDT?  

EDIT: Nevermind, got it.
Title: Re: EM3207 (v1.1) - MN3207 based EHX Electric Mistress (9V) clone
Post by: ricbox on July 13, 2012, 08:54:59 AM
I've got trouble on the DPDT wiring.

I've got the rear pad like this.

 1  -
 -   -
 -   -

How should I wire it following the scheme?

Title: Re: EM3207 (v1.1) - MN3207 based EHX Electric Mistress (9V) clone
Post by: Thomeeque on July 18, 2012, 08:11:41 AM
How should I wire it following the scheme?

 Probably like this:

 (http://thmq.mysteria.cz/em3207/build/sw_mode_DPDT_toggle_wiring.gif)

 For more precise answer I'd have to know exact pinout of your switch (it can be derived from the datasheet of the switch or determined by ohm-metter).

 T.
Title: Re: EM3207 (v1.1) - MN3207 based EHX Electric Mistress (9V) clone
Post by: ricbox on July 19, 2012, 04:28:19 PM
How should I wire it following the scheme?

 Probably like this:

 (http://thmq.mysteria.cz/em3207/build/sw_mode_DPDT_toggle_wiring.gif)

 For more precise answer I'd have to know exact pinout of your switch (it can be derived from the datasheet of the switch or determined by ohm-metter).

 T.
Thanks, I inverted SWa3/b1.
But now I've got a new problem: in the EM3007 I can't understand where pin 1 of the IC2 goes to. Is it VCC or GND? Because the PCB board I made from this image http://thmq.mysteria.cz/em3207/build/EM3007_v1.1/EM3007_v1.1_PCB_mirror_1200DPI.png  (http://thmq.mysteria.cz/em3207/build/EM3007_v1.1/EM3007_v1.1_PCB_mirror_1200DPI.png)
shows that pin 1 is connected to...nothing.
And the schematic shows it connected to...GND? Shouldn't this create a short?

I can hear the sound the guitar, a little whistle when turning the color pot, but it doesn't flange.
Title: Re: EM3207 (v1.1) - MN3207 based EHX Electric Mistress (9V) clone
Post by: Thomeeque on July 20, 2012, 05:06:28 AM
But now I've got a new problem: in the EM3007 I can't understand where pin 1 of the IC2 goes to. Is it VCC or GND? Because the PCB board I made from this image http://thmq.mysteria.cz/em3207/build/EM3007_v1.1/EM3007_v1.1_PCB_mirror_1200DPI.png  (http://thmq.mysteria.cz/em3207/build/EM3007_v1.1/EM3007_v1.1_PCB_mirror_1200DPI.png)
shows that pin 1 is connected to...nothing.
And the schematic shows it connected to...GND? Shouldn't this create a short?

 (http://thmq.mysteria.cz/em3207/build/EM3007_v1.1/EM3007_v1.1_names_IC2_jumper.gif)

 :) T.
Title: Re: EM3207 (v1.1) - MN3207 based EHX Electric Mistress (9V) clone
Post by: ricbox on July 20, 2012, 05:12:17 AM
But now I've got a new problem: in the EM3007 I can't understand where pin 1 of the IC2 goes to. Is it VCC or GND? Because the PCB board I made from this image http://thmq.mysteria.cz/em3207/build/EM3007_v1.1/EM3007_v1.1_PCB_mirror_1200DPI.png  (http://thmq.mysteria.cz/em3207/build/EM3007_v1.1/EM3007_v1.1_PCB_mirror_1200DPI.png)
shows that pin 1 is connected to...nothing.
And the schematic shows it connected to...GND? Shouldn't this create a short?

 (http://thmq.mysteria.cz/em3207/build/EM3007_v1.1/EM3007_v1.1_names_IC2_jumper.gif)

 :) T.
This slip will be the cause of my retirement from the DIY world.

haha, just joking! Thanks ;-)
Title: Re: EM3207 (v1.1) - MN3207 based EHX Electric Mistress (9V) clone
Post by: Thomeeque on July 20, 2012, 07:55:36 AM
 :) You're welcome.

 Btw. there's jumper-only layout EM3007_v1.1_jumpers_1200DPI.png (http://thmq.mysteria.cz/em3207/build/EM3007_v1.1/EM3007_v1.1_jumpers_1200DPI.png) provided, worth checking IMO.

 T.
Title: Re: EM3207 (v1.1) - MN3207 based EHX Electric Mistress (9V) clone
Post by: ricbox on July 22, 2012, 07:29:41 AM
Yep, in fact I missed some. I don't want to be much of an arse, but I really need big help on this.

During my first run, after soldering the jumpers, everything went bananas and smoke came out of the pcb. Still didn't know what damage did, probably the 2N5087 (Q2) got fried so I changed that.
Now I've got a signal that distorts first and then gets cleaner and cleaner and flanged 'till my ears hurts, and then returns to distorted.
I made a clip to prove it, with all the pots to the max and the trimpots set casually (RT3 to the MAX I believe), the filter switch up

http://soundcloud.com/riccardo-lomazzi/clip-em3007-not-working (http://soundcloud.com/riccardo-lomazzi/clip-em3007-not-working)

I really don't know where to begin set it right.
Title: Re: EM3207 (v1.1) - MN3207 based EHX Electric Mistress (9V) clone
Post by: Thomeeque on July 24, 2012, 04:54:01 AM
Yep, in fact I missed some.

 ::) Well, question now is what else did you miss.. go thru your build part by part and check carefully everything.. check soldering, PCB traces, component values, pinouts.. if you are able to make sharp high-res photos (both sides of the PCB, wiring, more angles) maybe we could help.

 From the sound sample we know that all function blocks (LFO, clock, BBD and rest of the audio path) work, just not properly. Modulation is very shallow (with RANGE and RT3 at max it should be really huge), check primarily C17 value (isn't it too small?). About distortion check primarily Q1 pinout/orientation (it's known bug in the EM3007 layout (http://thmq.mysteria.cz/em3207/build/EM3007_v1.1/EM3007_v1.1_names_1200DPI.png), now with big red warning sign). How did you adjust bias voltage?

 And you should of course find out why it did burn first time, there's no way how could faulty Q2 cause this if the rest was alright.

 If you will not succeed, follow instructions here (http://www.diystompboxes.com/smfforum/index.php?topic=29816.0).

RT3 to the MAX I believe..

 I don't want to be much of an arse either, but please know next time ;)

 T.
Title: Re: EM3207 (v1.1) - MN3207 based EHX Electric Mistress (9V) clone
Post by: ricbox on July 25, 2012, 06:02:40 PM

 From the sound sample we know that all function blocks (LFO, clock, BBD and rest of the audio path) work, just not properly. Modulation is very shallow (with RANGE and RT3 at max it should be really huge), check primarily C17 value (isn't it too small?). About distortion check primarily Q1 pinout/orientation (it's known bug in the EM3007 layout (http://thmq.mysteria.cz/em3207/build/EM3007_v1.1/EM3007_v1.1_names_1200DPI.png), now with big red warning sign). How did you adjust bias voltage?

So, Q1 was ok, because inverting it made the distortion disappear, but even the flanging effect.
Title: Re: EM3207 (v1.1) - MN3207 based EHX Electric Mistress (9V) clone
Post by: oldschoolanalog on July 25, 2012, 08:21:08 PM
Serious troubleshooting demands accurately posted voltages. As Tomas requested. Please do so.  ;)
That being said;
>>>>Rotating POT3 actually does, and it kinda flange the signal while I rotate it<<<<
This statement leads me to believe it is in "filter matrix" mode. Check your switch (SW) for correct wiring and function.
Please review and adhere to the Build Notes in the pdf. Tomas spent a lot of time and effort on this document. If followed carefully (along with reading this entire thread) there should be no issue too large to prevent successful completion of this flanger.
As far as flangers go, this is as simple as it gets.
We await your V's...
Title: Re: EM3207 (v1.1) - MN3207 based EHX Electric Mistress (9V) clone
Post by: Thomeeque on July 26, 2012, 07:53:47 AM
So, Q1 was ok, because inverting it made the distortion disappear, but even the flanging effect.

 Probably yes.

  • I removed the distortion by playing with RT1 (it's on half).

 Aren't you by any chance meaning RT2 when saying RT1 and vice versa?

 If yes, you have probably set optimal enough bias voltage this way.. Damn, I should have not been lazy to finish the ALIGNMENT PROCEDURE chapeter :(

 Keep it as it is for now, then later (when the rest is OK and with COLOR at zero) you may try to fine-tune it by ear or by scope for minimal distortion.

  • I changed the ICs, to be sure it wasn't one of them that got smoked.

 Good. Btw. do you already know why did it smoke?

  • Rotating RT2 to the max makes a very loud ears-breaker whistle

 If it's RT1 you are talking about and COLOR is at max., than it's normal (it's called self-oscillation and you adjust RT1 to point where it stops /or where you like it/ - another ALIGNMENT PROCEDURE step).

  • Rotating RT3 doesn't do anything

 Than you have something wrong around (check RT3, R31-R33, D1, C17, Q2, PCB..). PHOTOS, VOLTAGES!!!

  • Rotating POT3 actually does, and it kinda flange the signal while I rotate it

 Well and does it change depth of modulation (which you have very slow thanks to the next bullet) as well? If no check MODE switch wiring as Dave's said.

  • And oh, POT2 isn't set as a reverse-log. I mean, I just put it as it was.

 Then yet solder log/exp jumper according to BUILD NOTE 7 (without it RATE pot is not functional and acts as it was set to the slowest rate).

 @Dave - thanks, I should have spent yet little more time and effort on the ALIGNMENT PROCEDURE chapter :)
Title: Re: EM3207 (v1.1) - MN3207 based EHX Electric Mistress (9V) clone
Post by: ricbox on July 26, 2012, 12:14:58 PM
Ok, so, I apologize for being such a pain in the ass, but I managed to get all the voltages. I know that

I was so into many different pcb, that I printed this in horizontal reverse, so I had to CAREFULLY invert all the pins on the ICs and double check every component. Don't worry: I'm pretty sure the pins match the scheme.

The cause for the smoke was an incorrect position of the DC lug on the Voltage Supply. It runs at 9V (8.97 to be precise, but come on)

Here's the list.

Q1
E  8,75
B 4,75
C 3,9
Q2
E 8,47
B 7,35
C 1,71

IC1

1 1,67 5 8,7
2 1,42 6 1,7
3 1,19 7 1,4
4  0,00 8 1,5


IC2


1 8,47 5 4,4
2 5,9 6 VAR
3 0,19 7 4,7-5,0
4 0,4 8 0,00

IC3
1 2,44 8 1,7
2 1,42 9 1,7
3 8,64 10 1,6
4 4,0 11 0,00
5 3,9 12 3,8
6 3,8 13 3,9
7 3,6-4,2 14 3,9

IC4


1 0,00 5  8,75
2  2,3 6  5,9
3 1,7 7 8,6
4 0,00 8 8,6

IC5


1 5,4 8 8,6
2 5,4 9 8,7
3 5,7 10 0
4 0,00 11 0,00
5 5,4 12 0
6 0,00 13 0,00
7 0,00 14 0,00

IC6


1 8,6 9 0,00
2 5,8 10 6,0
3 5,9 11 6,0
4 5,9 12 0,00
5 5,4 13 6,7
6 0,00 14 6,0
7 5,4 15 6,7
8 2,8 16 6,0



RT1
1 0,00 (?)
2 0,00 (??)
3 0,00 (???)
RT2
1 8,6
2 1,6
3 0,00 ( connected to 27k R27)
RT3
1 2,2
2 8,2
3 8,2 (to diode)


Better if I host a pdf somewhere next time.
I swear I don't know why RT1 is going like this: it seems like it's in short. I fixed the eventual joints there, but it hasn't changed.
Oh, and I almost forgot: the LED bypass doesn't even work. I soldered it right, following the classic True Bypass Scheme, but it doesn't lights up.
Title: Re: EM3207 (v1.1) - MN3207 based EHX Electric Mistress (9V) clone
Post by: DLC86 on July 26, 2012, 02:02:02 PM
Hi everybody ;)
I need your opinion 'cuz I want to add a wet level control to this pedal. do you think it's better to add the pot in series with the output mixing resistor as a variable resistor, as a voltage divider or put the entire effect circuit in parallel with the dry line using a line mixer?
Thanks in advance
Title: Re: EM3207 (v1.1) - MN3207 based EHX Electric Mistress (9V) clone
Post by: Thomeeque on July 27, 2012, 08:59:01 AM
Ok, so, I apologize for being such a pain in the ass, but I managed to get all the voltages. I know that

I was so into many different pcb, that I printed this in horizontal reverse, so I had to CAREFULLY invert all the pins on the ICs and double check every component.

 :icon_eek: You have.. You did.. WHOAAAAA!!! ... OK, it took a while, but my heartbeat is back and eye-ball's diameter goes back to normal :) But now I definitely MUST see it!! :icon_mrgreen:

Don't worry: I'm pretty sure the pins match the scheme.

 Well if you have flipped legs of all ICs to back without breaking them and the IC's top (side with labels) is now bottom, it should be OK. But you must rotate transistors as well plus pot's will have reversed function (if directly soldered to the PCB from the top).

The cause for the smoke was an incorrect position of the DC lug on the Voltage Supply.

 Well, I'm trying to find out what impact could this event have for the circuit itself which I still don't have enough info for ("an incorrect position of the DC lug on the Voltage Supply" could mean lot of things, I need to know what happened "electrically" - shortcut on DC jack, reversed polarity on EM3007's DC pins..), but we can forget about it for now.

It runs at 9V (8.97 to be precise, but come on)

 Feel free to be precise (at least two valid digits with proper rounding applied, e.g. 9.0V here).

Here's the list.

 OK, where to start.. First, IC pin numbering goes in anti-clockwise circle, e.g.:

 (http://thmq.mysteria.cz/diystompboxes.com/4049_4050_pinout.gif)

 So all your right-side IC pin numbers have to be flipped vertically. But OK, I'm able to decode, just for the next time (and maybe to clear some of you confusion if you have tried to map between schemo and layouts)..

 Second, at some point you did flip Q1 pins C and E (C is at VCC so it must be like 8.7V, 3.9V is good value for E).

 Third, I see that I was wrong with my theory that you are interchanging RT1 and RT2. Long story short adjust RT2 to get VBias = 5.2V (measure VBias at IC1 pin 7 - normally you should measure it at pin 3 of IC2 but you have some mess there). 5.2V is proper bias for MN3007 at VCC = 9V according to datasheet where it must work somehow, you may fine-tune it later. As you have VBias (and Vref) so low now, that's not surprise that you have distortion there (at 1.7V there's not much of swing and used op-amps may not act linear in this area as well).

 Fourth, many of your measured values are very hard to believe. E.g. IC6 pin 6 at 0V when directly connected pins 9 and 11 are at 6V, IC1 pin 7 at 1.7V when directly connected IC2 pin 3 is at 0.19V (and there must be connection here because we have heard flanging), 8.2V at RT3 pins 2&3 when directly connected pins 5, 6 and 8 of IC4 have 8.7V, 2.8V at IC6 pin 8 (should be ground) etc. Even some of it may be the real problem, most probably you did just make errors when getting voltages..
 
 Setup VBias to those 5.2V and take new measurements at IC2, RT3, Q2 (identify E and C legs yet by some other connected part).

 Do new set of measurements at IC3 as well, there must be huge swing on pin 7 (rectangles, you must wait a while as you have probably slowest rate set, it's period should be around 6 seconds) and fluent up/down at pin 8 (triangles). For all pins with swing post lowest and highest value.

Better if I host a pdf somewhere next time.

 Whatever.

I swear I don't know why RT1 is going like this: it seems like it's in short. I fixed the eventual joints there, but it hasn't changed.

 There should be no DC voltage after C8 and C10, so values at RT1 pins seems correct.

Oh, and I almost forgot: the LED bypass doesn't even work. I soldered it right, following the classic True Bypass Scheme, but it doesn't lights up.

 Is this first pedal you are building?

 T.
Title: Re: EM3207 (v1.1) - MN3207 based EHX Electric Mistress (9V) clone
Post by: Thomeeque on July 27, 2012, 09:08:47 AM
Hi everybody ;)
I need your opinion 'cuz I want to add a wet level control to this pedal. do you think it's better to add the pot in series with the output mixing resistor as a variable resistor, as a voltage divider or put the entire effect circuit in parallel with the dry line using a line mixer?
Thanks in advance

 Depends on the control range and let's say total "fidelity" you want to achieve (original output mixer is complex passive circuitry, changing mixing resistor value influences even frequency characteristics, proper de-emphasis, output volume and impedance). If you are not sure, start with trying e.g. 100k pot instead of R18 and see (hear :)). If using external mixer remember that you should apply de-emphasis to all signals after IC1B output.

 Good luck, T.
Title: Re: EM3207 (v1.1) - MN3207 based EHX Electric Mistress (9V) clone
Post by: oldschoolanalog on July 27, 2012, 10:17:49 AM
@ ricbox: Just a thought, FWIW. Please consider the option of etching a correct board and starting over. This way you could build it and test the sections as you go. Also, any troubleshooting will be easier for all parties involved. Consider this a learning experience and move ahead.  :icon_cool:
@ Tomas: I feel your pain...  ;)
Title: Re: EM3207 (v1.1) - MN3207 based EHX Electric Mistress (9V) clone
Post by: Thomeeque on July 27, 2012, 10:56:20 AM
@ ricbox: Just a thought, FWIW. Please consider the option of etching a correct board and starting over. This way you could build it and test the sections as you go. Also, any troubleshooting will be easier for all parties involved. Consider this a learning experience and move ahead.  :icon_cool:

 On the other hand first EM3007 v1.1 *Mirror Edition* sounds prettty tempting :icon_mrgreen:

@ Tomas: I feel your pain...  ;)

 

 ;) Thanks, T.
Title: Re: EM3207 (v1.1) - MN3207 based EHX Electric Mistress (9V) clone
Post by: DLC86 on July 27, 2012, 08:41:03 PM
Depends on the control range and let's say total "fidelity" you want to achieve (original output mixer is complex passive circuitry, changing mixing resistor value influences even frequency characteristics, proper de-emphasis, output volume and impedance). If you are not sure, start with trying e.g. 100k pot instead of R18 and see (hear :)). If using external mixer remember that you should apply de-emphasis to all signals after IC1B output.

 Good luck, T.
Thank you, I'll give it a try as soon as I have 5 spare minutes... ;)
but I had another (maybe stupid) idea: what if I use the pot to change the gain on the transistor at Bbd output? Will this avoid those side effects?
Title: Re: EM3207 (v1.1) - MN3207 based EHX Electric Mistress (9V) clone
Post by: ricbox on July 28, 2012, 05:38:05 AM
Ok, so, I apologize for being such a pain in the ass, but I managed to get all the voltages. I know that

I was so into many different pcb, that I printed this in horizontal reverse, so I had to CAREFULLY invert all the pins on the ICs and double check every component.

 :icon_eek: You have.. You did.. WHOAAAAA!!! ... OK, it took a while, but my heartbeat is back and eye-ball's diameter goes back to normal :) But now I definitely MUST see it!! :icon_mrgreen:

Don't worry: I'm pretty sure the pins match the scheme.

 Well if you have flipped legs of all ICs to back without breaking them and the IC's top (side with labels) is now bottom, it should be OK. But you must rotate transistors as well plus pot's will have reversed function (if directly soldered to the PCB from the top).

The cause for the smoke was an incorrect position of the DC lug on the Voltage Supply.

 Well, I'm trying to find out what impact could this event have for the circuit itself which I still don't have enough info for ("an incorrect position of the DC lug on the Voltage Supply" could mean lot of things, I need to know what happened "electrically" - shortcut on DC jack, reversed polarity on EM3007's DC pins..), but we can forget about it for now.

It runs at 9V (8.97 to be precise, but come on)

 Feel free to be precise (at least two valid digits with proper rounding applied, e.g. 9.0V here).

Here's the list.

 OK, where to start.. First, IC pin numbering goes in anti-clockwise circle, e.g.:

 (http://thmq.mysteria.cz/diystompboxes.com/4049_4050_pinout.gif)

 So all your right-side IC pin numbers have to be flipped vertically. But OK, I'm able to decode, just for the next time (and maybe to clear some of you confusion if you have tried to map between schemo and layouts)..

 Second, at some point you did flip Q1 pins C and E (C is at VCC so it must be like 8.7V, 3.9V is good value for E).

 Third, I see that I was wrong with my theory that you are interchanging RT1 and RT2. Long story short adjust RT2 to get VBias = 5.2V (measure VBias at IC1 pin 7 - normally you should measure it at pin 3 of IC2 but you have some mess there). 5.2V is proper bias for MN3007 at VCC = 9V according to datasheet where it must work somehow, you may fine-tune it later. As you have VBias (and Vref) so low now, that's not surprise that you have distortion there (at 1.7V there's not much of swing and used op-amps may not act linear in this area as well).

 Fourth, many of your measured values are very hard to believe. E.g. IC6 pin 6 at 0V when directly connected pins 9 and 11 are at 6V, IC1 pin 7 at 1.7V when directly connected IC2 pin 3 is at 0.19V (and there must be connection here because we have heard flanging), 8.2V at RT3 pins 2&3 when directly connected pins 5, 6 and 8 of IC4 have 8.7V, 2.8V at IC6 pin 8 (should be ground) etc. Even some of it may be the real problem, most probably you did just make errors when getting voltages..
 
 Setup VBias to those 5.2V and take new measurements at IC2, RT3, Q2 (identify E and C legs yet by some other connected part).

 Do new set of measurements at IC3 as well, there must be huge swing on pin 7 (rectangles, you must wait a while as you have probably slowest rate set, it's period should be around 6 seconds) and fluent up/down at pin 8 (triangles). For all pins with swing post lowest and highest value.

Better if I host a pdf somewhere next time.

 Whatever.

I swear I don't know why RT1 is going like this: it seems like it's in short. I fixed the eventual joints there, but it hasn't changed.

 There should be no DC voltage after C8 and C10, so values at RT1 pins seems correct.

Oh, and I almost forgot: the LED bypass doesn't even work. I soldered it right, following the classic True Bypass Scheme, but it doesn't lights up.

 Is this first pedal you are building?

 T.

First of all, THANK YOU so much for being supportive. You don't expect it that much from the direct creator of a project, this is a nice surprise.

And no, it's not my first build: I previously made a BOSS CE-2 Clone, and I think you know well how hard it is to bias it. But I made it!
This one is giving me problems, particularly beacause I haven't understood well the different sections of the scheme. Not blaming your faults, you did a monstrous job with this pcb.

But I realize that projects like this need patience and constance, two things that I had when I built the CE-2, but I don't have right now. I'm really, not in the mood (women problems lol). I won't be asking for help anymore, I think I'm gonna give it up. Maybe I'll take another look at it someday.

Thanks again for your help.
Title: Re: EM3207 (v1.1) - MN3207 based EHX Electric Mistress (9V) clone
Post by: Thomeeque on July 30, 2012, 06:27:37 AM
Maybe I'll take another look at it someday.

 I strongly hope so..

but I had another (maybe stupid) idea: what if I use the pot to change the gain on the transistor at Bbd output? Will this avoid those side effects?

 That seems clever, unfortunately this pot would affect amount of feedback ("color") adjusted by the COLOR pot as well.

 Btw. feedback brings another complication maybe (depending on what exactly you are up to again): even "dry" signal path R16-C10 contain the feedback signal, so it's not completely dry (it's completely dry only when COLOR is at zero).

 T.
Title: Re: EM3207 (v1.1) - MN3207 based EHX Electric Mistress (9V) clone
Post by: DLC86 on July 30, 2012, 08:28:54 AM
That seems clever, unfortunately this pot would affect amount of feedback ("coor") adjusted by theCOLOR pot as well.

 Btw. feedback brings another complication maybe (depending on what exactly you are up to again): even "dry" signal path R16-C10 contain the feedback signal, so it's not completely dry (it's completely dry only when COLOR is at zero).
well, i figured it out looking at the schemo again..
Anyway yesterday I tried several solutions, firstly a 100k and a 250k lin pots in series with r18 and both worked only in the last quarter of turn, maybe it would have been needed a rev log taper. anyway I ended up with a 100k pot set as voltage divider (with lug 1 to ground) placed between 2 100nF caps before r18 and it works perfectly for my needs, now I can achieve those Wall tones where the mistress is set lower in the mix. The only issues are a very little interaction with the color pot and changes in the overall volume but it doesn't bother me since I have the old version of the PCB with the booster on the output.

Thanks for your help and for this great pedal once again.

P.s: If it's not clear what I did I can draw a little schematic
Title: Re: EM3207 (v1.1) - MN3207 based EHX Electric Mistress (9V) clone
Post by: Thomeeque on July 30, 2012, 09:15:00 AM
 Great, congrats! :)

anyway I ended up with a 100k pot set as voltage divider (with lug 1 to ground) placed between 2 100nF caps before r18

 If you mean like this:

 (http://thmq.mysteria.cz/em3207/build/EM3x07_wet_lvl_by_DLC86.gif)

 you could have wired pot there directly without those caps, there's no DC to be decoupled at this point.

 Maybe you could post some sound sample of your favourite setting compared to the same setting with "full" wet, so others have idea..?

 Cheers, T.
Title: Re: EM3207 (v1.1) - MN3207 based EHX Electric Mistress (9V) clone
Post by: DLC86 on July 30, 2012, 11:52:30 AM
Yes, exactly!
I've added those caps just because my electronics knowledge is almost totally empiric :'( : when I was working on the echobase (that has a similar arrangement in that section) i remember that the level pot was way more interacting with the feedback without the decoupling caps, so I thought it was the same here. Anyway I'll even try without those caps.
About the samples, I'll se If i can do'em tomorrow afternoon.  ;)
Cheers
Title: Re: EM3207 (v1.1) - MN3207 based EHX Electric Mistress (9V) clone
Post by: ricbox on July 31, 2012, 08:50:11 AM
So, I finally trimmed vbias to 5.2 and did a new set of voltages. Now I can hear the flanging, but still distorts, and if I turn the Color pot, it distorts more.

IC3, pin 7 and 8 are SWAPPED IN THE IMAGE (sorry)

(http://i49.tinypic.com/dy206b.jpg)



Title: Re: EM3207 (v1.1) - MN3207 based EHX Electric Mistress (9V) clone
Post by: oldschoolanalog on July 31, 2012, 09:09:46 AM
Okay, you are close. Realize Vbias might not be exactly 5.2V. It often varies slightly from chip to chip. Try adjusting Vbias in small increments while checking your signal for distortion. You are probably just a bit off.
Title: Re: EM3207 (v1.1) - MN3207 based EHX Electric Mistress (9V) clone
Post by: ricbox on July 31, 2012, 11:43:31 AM
Okay, you are close. Realize Vbias might not be exactly 5.2V. It often varies slightly from chip to chip. Try adjusting Vbias in small increments while checking your signal for distortion. You are probably just a bit off.
Listening again after trimming, it distorts just in the "feedback" trait. I mean, you can hear like a sea wave sound if you don't do anything. The "return to shore" is distorted, and it happens 1 sec later. It scratches.

I've recorded a clip to make you hear better.

http://soundcloud.com/riccardo-lomazzi/em3007-scratching
Title: Re: EM3207 (v1.1) - MN3207 based EHX Electric Mistress (9V) clone
Post by: DLC86 on July 31, 2012, 08:14:56 PM
http://soundcloud.com/dlc86/sample-mistress
here's a little sample i made to show the difference between wet level at 50% and on full. sorry for the poor quality but i recorded it with the pedalboard directly injected into the sound card.  :-X
sound isn't quite the same when i plug into my hiwatt  :-\ but I hope this will give you an idea anyway...
Title: Re: EM3207 (v1.1) - MN3207 based EHX Electric Mistress (9V) clone
Post by: 12Bass on August 01, 2012, 09:29:26 AM
http://soundcloud.com/dlc86/sample-mistress
here's a little sample i made to show the difference between wet level at 50% and on full. sorry for the poor quality but i recorded it with the pedalboard directly injected into the sound card.  :-X
sound isn't quite the same when i plug into my hiwatt  :-\ but I hope this will give you an idea anyway...
Glad you persevered.  There's definitely some flanging happening there, so that means the the circuit is working.  Seems like the flanger might have put your guitar a little out of tune... ;)

Here's some info on how to find the optimal bias and wet/dry mix (for A/DA, but will also work for the EM):http://www.diystompboxes.com/smfforum/index.php?topic=96605.msg839822#msg839822
Title: Re: EM3207 (v1.1) - MN3207 based EHX Electric Mistress (9V) clone
Post by: DLC86 on August 01, 2012, 09:52:44 AM
Seems like the flanger might have put your guitar a little out of tune... ;)
Shame on me!!  ;D I've recorded that sample really "on the run" and with my old 50€ strat which has 1year old strings on :icon_razz:
Thanks for the link, I'll give it a look as soon as I can

EDIT: mmm... maybe your message was for ricbox?
Title: Re: EM3207 (v1.1) - MN3207 based EHX Electric Mistress (9V) clone
Post by: 12Bass on August 01, 2012, 10:36:20 AM
EDIT: mmm... maybe your message was for ricbox?

Oops... sorry, it was.... didn't read closely enough.   :icon_redface:
Title: Re: EM3207 (v1.1) - MN3207 based EHX Electric Mistress (9V) clone
Post by: ricbox on August 02, 2012, 05:03:52 PM
EDIT: mmm... maybe your message was for ricbox?

Oops... sorry, it was.... didn't read closely enough.   :icon_redface:
Damn, that's a sign I really broke some balls heheh
Thanks for the link, but I think it will become useful when I'll figure out what's wrong with that swoosh. I mean, you can tell it's like a feedback swoosh, so there must be something wrong with some components.
Title: Re: EM3207 (v1.1) - MN3207 based EHX Electric Mistress (9V) clone
Post by: Thomeeque on August 06, 2012, 05:24:28 AM
http://soundcloud.com/dlc86/sample-mistress
here's a little sample i made to show the difference between wet level at 50% and on full. sorry for the poor quality but i recorded it with the pedalboard directly injected into the sound card.  :-X
sound isn't quite the same when i plug into my hiwatt  :-\ but I hope this will give you an idea anyway...

 Hi DLC86, thanks a lot for this demo, that is really interesting! Very delicate sound with those 50%, definitely to-be-considered feature for all us gilmourish! ;)

 Btw. hiwatt clone is on my TODO list, I just have to get right output transformer (for the reasonable price) which is not exactly easy here in Prague.

 T.
Title: Re: EM3207 (v1.1) - MN3207 based EHX Electric Mistress (9V) clone
Post by: Thomeeque on August 06, 2012, 05:43:16 AM
I've recorded a clip to make you hear better.

http://soundcloud.com/riccardo-lomazzi/em3007-scratching

 Definitely sick sound, not only distortion but sweep (modulation) as well. Is it still true, that RT3 adjustment has no influence? Did you doublecheck C17 value?

 Can you make those hi-res photos I have asked you already for? If you are too shy to show them here :D, send them to me via PM.

 Btw. if you want to, you may pack your build with some beer money and money for post back and send it to me, I could probably fix it easily if I have it in my hands (if yes send me PM to tune-up details).

 T.
Title: Re: EM3207 (v1.1) - MN3207 based EHX Electric Mistress (9V) clone
Post by: DLC86 on August 06, 2012, 09:08:13 AM
Hi DLC86, thanks a lot for this demo, that is really interesting! Very delicate sound with those 50%, definitely to-be-considered feature for all us gilmourish! ;)

 Btw. hiwatt clone is on my TODO list, I just have to get right output transformer (for the reasonable price) which is not exactly easy here in Prague.

 T.
Yes, it's a very useful feature, previously i kept lowering the color pot & trim to obtain that sound but it wasn't quite the same. now it's perfect for me.
For the hiwatt trannie you can check this site (http://beppetrasfo.altervista.org/), that's where i bought mine, he stopped his business but in that page he says he has the last set for a dr103 (PT+OT) for 118€. Maybe you can try to send him an email ;)
Title: Re: EM3207 (v1.1) - MN3207 based EHX Electric Mistress (9V) clone
Post by: Thomeeque on August 06, 2012, 09:39:23 AM
Maybe you can try to send him an email ;)

 I just did :) 118E would be nice price for set of both trannies! So thanks again! :) T.
Title: Re: EM3207 (v1.1) - MN3207 based EHX Electric Mistress (9V) clone
Post by: ricbox on August 06, 2012, 05:12:35 PM
I've recorded a clip to make you hear better.

http://soundcloud.com/riccardo-lomazzi/em3007-scratching

 Definitely sick sound, not only distortion but sweep (modulation) as well. Is it still true, that RT3 adjustment has no influence? Did you doublecheck C17 value?

 Can you make those hi-res photos I have asked you already for? If you are too shy to show them here :D, send them to me via PM.

 Btw. if you want to, you may pack your build with some beer money and money for post back and send it to me, I could probably fix it easily if I have it in my hands (if yes send me PM to tune-up details).

 T.

Doublechecked cap n. 17, it's a ceramic 22 pF with 1.01V passing through it ;-) .

I'm at my wits' end, and to celebrate it, let's put another clip online!
http://soundcloud.com/riccardo-lomazzi/em3007-plucking
 (http://soundcloud.com/riccardo-lomazzi/em3007-plucking)

Can you hear that "pluck" and the end of the wave? Its high volume makes it all strange to me.

Could I subtrack myself to public humiliation? Of course not! Ladies and gentleman, here's the ugly, clingy, mirrored version of the EM3007!

(http://i46.tinypic.com/6dzj8w.jpg)

(http://i48.tinypic.com/2j1oshw.jpg)

(http://i47.tinypic.com/117d5hu.jpg)
Title: Re: EM3207 (v1.1) - MN3207 based EHX Electric Mistress (9V) clone
Post by: Thomeeque on August 09, 2012, 10:14:21 AM
Could I subtrack myself to public humiliation? Of course not! Ladies and gentleman, here's the ugly, clingy, mirrored version of the EM3007!

 It's actually not that bad.

 Scratches on the PCB are removed bridges between the traces? Did you check by DMM that bridges are removed (visual check is sometimes not good enough)?

 Unfortunately you have gave us only one view of each area (I have asked for more angles), so I cannot check lot of the components and wiring. What I could check (most of the resistors and caps around LFO and clock, Q's orientation, pot wiring, mode switch wiring..) looks OK.

 Soundclip sounds like some DC problem, what power source are you using? Can you try different one? You have not answered my question about RT3 either, there could be another lead to plucking issue (clock freeze above some frequency - but it sounds quite different IIRC).

 About distortion one thing popped up in my head - you have mentioned that status LED does not work - is it still true? If yes maybe miswired LED hangs on the output and causes overdrive effect..?

 T.
Title: Re: EM3207 (v1.1) - MN3207 based EHX Electric Mistress (9V) clone
Post by: Thomeeque on August 09, 2012, 10:19:31 AM
..wrong button..
Title: Re: EM3207 (v1.1) - MN3207 based EHX Electric Mistress (9V) clone
Post by: ricbox on August 17, 2012, 04:23:10 AM
Could I subtrack myself to public humiliation? Of course not! Ladies and gentleman, here's the ugly, clingy, mirrored version of the EM3007!

 It's actually not that bad.

 Scratches on the PCB are removed bridges between the traces? Did you check by DMM that bridges are removed (visual check is sometimes not good enough)?

 Unfortunately you have gave us only one view of each area (I have asked for more angles), so I cannot check lot of the components and wiring. What I could check (most of the resistors and caps around LFO and clock, Q's orientation, pot wiring, mode switch wiring..) looks OK.

 Soundclip sounds like some DC problem, what power source are you using? Can you try different one? You have not answered my question about RT3 either, there could be another lead to plucking issue (clock freeze above some frequency - but it sounds quite different IIRC).

 About distortion one thing popped up in my head - you have mentioned that status LED does not work - is it still true? If yes maybe miswired LED hangs on the output and causes overdrive effect..?

 T.

Ok, so, changing the Led's wiring made it work, but the sound's still popping like before.
About RT3, sorry for oversighting the question, if I turn the wheel to the max or to the min,  it starts whistling and my ears begin to explode.

The power source is a Regulated Universal Voltage Adapter by HQ Power, working at MAX 500mA and outputs values between 1,5 and 12 Vdc. Power is 6VA. It whistles a bit, but it works nonetheless.
The first smoke was totally a polarity problem.

I began to wonder, could it be the Diodes? I'm currently measuring 0.35V on D1, oscillating 0,00-0,42 on D2 and 8.03 on Zener D3 (yeah, it's a 15V).

I think we're close to the solution, apart from this popping problem it's a really fun pedal, do you know how much I searched it at good price to play a Rush song with a decent sound? And then I found this thread...I will surely reward you all with some Rush covers (yeeee)

..wrong button..
I hope you're not referring to the SPDT.
Title: Re: EM3207 (v1.1) - MN3207 based EHX Electric Mistress (9V) clone
Post by: ricbox on August 19, 2012, 04:55:56 AM
I forgot about RT3: it pretty much works like it should do (at least I think), but the pops are always there when I turn the trimpot.
Title: Re: EM3207 (v1.1) - MN3207 based EHX Electric Mistress (9V) clone
Post by: juanjuin on September 03, 2012, 11:37:13 AM
hello mr T
i have done build EM3207, but i have some question for you mr t
1. i put the pot offboard and the cable is about 10 cm, is that make my pedal didn't flanging?
2. i still understand about RT1, RT2, RT3, can you tell me with clock analogy?
3. i have put rt2 to the max the my pedal sound is distort like noise, and very little sound, is that wrong?

please mr T answer me, and sorry for my bad english. i'm Indonesian, sorry for my bad english.
thankyou
-juan-
Title: Re: EM3207 (v1.1) - MN3207 based EHX Electric Mistress (9V) clone
Post by: Thomeeque on September 11, 2012, 06:40:43 AM
hello mr T
i have done build EM3207, but i have some question for you mr t
1. i put the pot offboard and the cable is about 10 cm, is that make my pedal didn't flanging?

 Hello juan, no, this may introduce some (ticking) noise issues but it may not cause anything fatal, there must be some other problem.

 Read this post (http://www.diystompboxes.com/smfforum/index.php?topic=91981.msg830595#msg830595) (Reply #245), try to align your unit first.

2. i still understand about RT1, RT2, RT3, can you tell me with clock analogy?

 RT1 = FEEDBACK trim, it's there to fine-tune COLOR pot range
 RT2 = BIAS trim, sets proper bias voltage at the BBD chip
 RT3 = CLOCK trim, it's there to fine-tune range of the clock frequency sweep

 If you want more details start by learning how FLANGER effect works, how BBD works etc., use google..

3. i have put rt2 to the max the my pedal sound is distort like noise, and very little sound, is that wrong?

 No, it's OK, you have moved bias voltage to the area where nothing can work properly..

please mr T answer me, and sorry for my bad english. i'm Indonesian, sorry for my bad english.
thankyou
-juan-

 No problem mr. J ;), good luck, T.
Title: Re: EM3207 (v1.1) - MN3207 based EHX Electric Mistress (9V) clone
Post by: juanjuin on September 14, 2012, 01:01:43 PM
it works mr T thankyou so much
but flanging sound is very small, i still can hear small flange
then i replace R5 with 10k but still small
for information i put RT1 half, RT2 4/10 (11 o'clock), and RT3 to the max
what should i do mr t?
sorry for my bad english
-juan-
Title: Re: EM3207 (v1.1) - MN3207 based EHX Electric Mistress (9V) clone
Post by: Oneoff1 on February 10, 2013, 08:11:16 PM
hi all! :)
i finished the EM3207 but unfortunately it's not working. what actually happens is that R36 (47ohm) is on fire even when i use 9v battery.
 i checked all my connections chips and caps positions and if the board has any shorts ... nothing to be found.
any ideas?
Title: Re: EM3207 (v1.1) - MN3207 based EHX Electric Mistress (9V) clone
Post by: DLC86 on February 10, 2013, 08:26:42 PM
Check the zener diode orientation ;)
Title: Re: EM3207 (v1.1) - MN3207 based EHX Electric Mistress (9V) clone
Post by: Oneoff1 on February 11, 2013, 06:29:25 PM
hi, thank's but the zener was the first thing i checked...
 it's got to do something within the PSU area but i cant find any flaw here
Title: Re: EM3207 (v1.1) - MN3207 based EHX Electric Mistress (9V) clone
Post by: Dave W on February 11, 2013, 11:00:17 PM
V's please.
Title: Re: EM3207 (v1.1) - MN3207 based EHX Electric Mistress (9V) clone
Post by: Oneoff1 on February 11, 2013, 11:43:38 PM
V's please.

can you please explain what do you mean?
Title: Re: EM3207 (v1.1) - MN3207 based EHX Electric Mistress (9V) clone
Post by: armdnrdy on February 12, 2013, 12:08:15 AM
He means voltages.

Voltage readings from the pins of the op amps and transistors. Pins to ground if you don't know that!  ;)
Title: Re: EM3207 (v1.1) - MN3207 based EHX Electric Mistress (9V) clone
Post by: Thomeeque on February 12, 2013, 04:42:16 AM
 Guys, when some part is burning it's not exactly good time for taking measurements on all IC's and Q's pins ;)

 Only voltages I'd maybe advice to quickly measure would be voltages on both pins of R36 (against GND), this can tell us more about character of shortage causing R36 to burn.

 D3 (zener diode) cannot cause the problem, R35 would be burning, not R36. Shortage is somewhere after R36, which is VDD supply rail.

 First pull out IC3 (LM324) and check if it changes situation - if yes, use new one. If not left IC3 out until issue is fixed and check rest of the VDD path (bridges on PCB, C20, RT2, jumpers.. follow schematic), there must be something.

 Good luck, T.

 PS: If you want other set of eyes to help, make sharp photos of the PCB (both sides) and let us look.
Title: Re: EM3207 (v1.1) - MN3207 based EHX Electric Mistress (9V) clone
Post by: Oneoff1 on February 12, 2013, 10:53:09 AM
Thomeeque, thanks a lot for the reply!
i will check everything again thoroughly and i'll post some pictures if nothing is found.
Title: Re: EM3207 (v1.1) - MN3207 based EHX Electric Mistress (9V) clone
Post by: Oneoff1 on February 13, 2013, 11:14:21 PM
OK guys! i got it !  -it was a nasty little bridge on the PCB,  a flaw in my etching , i got it and i cant believe i did because it was so tiny...

BUT unfortunately i cant get the flanger to work properly. :icon_sad:
i can hear the output as is , no influence on the sound. it distorts when i put up the input gain but it's probably normal...

i don't think that there is a clock in my circuit whatever i do with RT2. and the SW_mode isn't effecting anything .
i started with the bias setting and set that exactly as Thomeeque explained before. V bias (at pin 3 of the bbd chip) = 0.42 +0.54*Vcc
which is 0.42+0.54*9.08 = 5.32V
i tried to replace the BBD chip twice but without any difference.
i guess i have no effect because the clock is not present?

one thing to say is that i didn't connect anything yet to pads 10 and 11 (CC) should I?
Title: Re: EM3207 (v1.1) - MN3207 based EHX Electric Mistress (9V) clone
Post by: Thomeeque on February 14, 2013, 11:48:46 AM
OK guys! i got it !  -it was a nasty little bridge on the PCB,  a flaw in my etching , i got it and i cant believe i did because it was so tiny...

 Great, congrats :)

BUT unfortunately i cant get the flanger to work properly. :icon_sad:
i can hear the output as is , no influence on the sound. it distorts when i put up the input gain but it's probably normal...

 At this point (no fire :)) following DEBUGGING - What to do when it doesn't work (http://www.diystompboxes.com/smfforum/index.php?topic=29816.0) instructions is most effective way how to let us help you..

i don't think that there is a clock in my circuit whatever i do with RT2. and the SW_mode isn't effecting anything .

 To check clock+BBD build audio-probe and check BBD output.
 To check clock measure DC voltage at BBD's clock inputs CP1 and CP2, normal DMM in DC mode should see there cca half of VCC.

i started with the bias setting and set that exactly as Thomeeque explained before. V bias (at pin 3 of the bbd chip) = 0.42 +0.54*Vcc
which is 0.42+0.54*9.08 = 5.32V

 Well done :)

one thing to say is that i didn't connect anything yet to pads 10 and 11 (CC) should I?

 No, it is for delay range mod, leave mods until basic circuit works.

 T.
Title: Re: EM3207 (v1.1) - MN3207 based EHX Electric Mistress (9V) clone
Post by: Oneoff1 on February 14, 2013, 06:44:07 PM
thank's a lot !
i'll try to debug and measure according to the instructions... very useful!
Title: Re: EM3207 (v1.1) - MN3207 based EHX Electric Mistress (9V) clone
Post by: Oneoff1 on February 16, 2013, 11:37:54 PM
ok I got the flanger working !  ;D
there was something wrong with the 324 so i tried another chip ... and after setting RT2 and fiddling  with C17 a bit with another cap in parallel i got a beautiful 'airplane' kind of effect !
now , the only problem is that the rate knob is not effecting the rate . i got a steady slow rate . mmm.  :icon_confused:
after checking the schematics again i noticed that the middle pad of the rate pot is not connected to anything???
is it just me or there is something strange with it?
Title: Re: EM3207 (v1.1) - MN3207 based EHX Electric Mistress (9V) clone
Post by: Thomeeque on February 17, 2013, 04:38:28 AM
ok I got the flanger working !  ;D
there was something wrong with the 324 so i tried another chip ... and after setting RT2 and fiddling  with C17 a bit with another cap in parallel i got a beautiful 'airplane' kind of effect !

 Great! So what capacity you have at C17 now?

now , the only problem is that the rate knob is not effecting the rate . i got a steady slow rate . mmm.  :icon_confused:
after checking the schematics again i noticed that the middle pad of the rate pot is not connected to anything???
is it just me or there is something strange with it?

 You have somehow missed build note 7.. ::)

 T.
Title: Re: EM3207 (v1.1) - MN3207 based EHX Electric Mistress (9V) clone
Post by: Oneoff1 on February 17, 2013, 12:06:09 PM
Quote
You have somehow missed build note 7..
that's right! i thought that if i'm using the REV LOG potentiometer i should leave this pad as is...
now all is good  :) i have a great flanging effect.
i still don't know how exactly to set up RT3 to the "right" set up , something there is not linear and kind of confusing as the trimmer starts to effect the clock in a certain area and then it get to have a 'intermittent' effect on the range pot. i'm not sure how to describe it
what should be the right setup with RT3? what should be the resistance there?

Quote
Great! So what capacity you have at C17 now?
Ok, so because i'm using this effect as a part in my DIY modular synthesizer i want to give it some more options.
so i decided to have a 6 position switch with different capacitors this can be useful for making a subtle flange
with strings or a total chaos with a drum machine for instance. i found out that when i'm touching the leads of C17  i'm
changing the range in different ways so maybe i'll add a touch pad to that section...
i'm also going to try to add some vactrols to the circuit in order to have CV control over the pots.
i guess that the experiments can be endless with that circuit...

the caps i'm using for C17:
1nf (the more 'standard' effect)
1.1nf
2.2nf
3nf
10 nf
27nf (meteor crush effect :)
and i'm still trying more values...


BTW i found out that when using the NJM4558D i got a nicer sound . i also found differences between different 3207 ic's.

Thank's a lot for this great project!!


Title: Re: EM3207 (v1.1) - MN3207 based EHX Electric Mistress (9V) clone
Post by: Thomeeque on February 18, 2013, 09:34:11 AM
i still don't know how exactly to set up RT3 to the "right" set up..

 RT3 is there for fine-tuning sweep range, there is some factory alignment procedure, see this post (http://www.diystompboxes.com/smfforum/index.php?topic=91981.msg830595#msg830595) again, but you can simply dial range you like and be happy with it - it is yet more complicated in your case, bacause original factory alignment procedure expects one specific C17 value (47pF probably) and you have many.

Ok, so because i'm using this effect as a part in my DIY modular synthesizer i want to give it some more options.
...
Thank's a lot for this great project!!

 1nF to 27nF? It's pretty far from original 47pF :) It would be nice if you would create some demo of the way you use it, as it seems unique and interesting in more aspects.

 Btw. consider this simple "odd/even" mod (http://www.diystompboxes.com/smfforum/index.php?topic=91981.msg809258#msg809258), there are links to demo where you can hear it, I think you may like it :)

BTW i found out that when using the NJM4558D i got a nicer sound . i also found differences between different 3207 ic's.

 Yep, could be.

 T.
Title: Re: EM3207 (v1.1) - MN3207 based EHX Electric Mistress (9V) clone
Post by: Oneoff1 on February 18, 2013, 03:38:00 PM
Quote
there is some factory alignment procedure
i went back to that post but i cant find it... should i look in the IC spec sheet?

Quote
1nF to 27nF? It's pretty far from original 47pF
yes, i cant get any effect with 22pf installed alone,but when i add 47pf in parallel i get it. i have nicer results with 1000pf...
strange ha? i probably made a mistake somewhere or set the clock trimmer way off but whatever i tried with PR3 the results with C17 (22pf) alone are the same- no flanging effect.

Also when experimenting with small values (in the 22pf -100pf area) caps in parallel to C17
i get some noise / clipping sound (depends on the position of PR3) when the effect sweeps to it's 'peak' . that can't be avoided
no matter what i do withe the trimmers. this, for example isn't happening with 1000pf cap installed...

i'm lucky that i like noise sometimes :)

Quote
It would be nice if you would create some demo of the way you use it, as it seems unique and interesting in more aspects.
sure , i will post a demo when ill finish (and solder everything together). right now it's a mess...

also , thank's for the odd/even mod info,
i appreciate your replies and help!


Title: Re: EM3207 (v1.1) - MN3207 based EHX Electric Mistress (9V) clone
Post by: Thomeeque on February 20, 2013, 10:06:48 AM
Quote
there is some factory alignment procedure
i went back to that post but i cant find it... should i look in the IC spec sheet?

 Post contains link to the web page dedicated to all possible EM's alignment procedures..

yes, i cant get any effect with 22pf installed alone,but when i add 47pf in parallel i get it. i have nicer results with 1000pf...

 Frequency range of EM's clock is limited (going beyond this limit freezes clock which leads to audible pops when limit is crossed), that is correct behavior.

 On the other hand if you were not able to adjust RT3 even with C17=22pF to the position, where full sweep range worked, you still have something fishy there.

 Btw. I do not recommend 22pF as C17 anymore (since I know that clock frequency is not doubled this way properly and natural sweep gets cripled), use 47pF there.

 T.
Title: Re: EM3207 (v1.1) - MN3207 based EHX Electric Mistress (9V) clone
Post by: carfranca on June 30, 2013, 12:40:34 AM
Wow! Excellent pedal! Congratulations Tomas. I had similar problems to the user ricbox and decided checking all tracks. Before, I reviewed all components. Disassembled and remade the circuit carefully. The problem persisted. Then, using a magnifying glass I reviewed all the tracks and bingo! There was a short track by a thin layer of copper. Problem solved! My EM3207 is 'flanging'...  :icon_biggrin:
Title: Re: EM3207 (v1.1) - MN3207 based EHX Electric Mistress (9V) clone
Post by: Thomeeque on July 04, 2013, 09:41:00 AM
 Thanks and congratulations to successful debugging, I'm glad you like the result :)
Title: Re: EM3207 (v1.1) - MN3207 based EHX Electric Mistress (9V) clone
Post by: DrAlx on July 23, 2013, 02:19:41 AM
I have done a stripboard layout for the EM3207 and built it.  It worked first time  :)
I am pleased with the result and the layout is only slightly larger in area than Thomeeque's PCB.

To make the layout compact, I swapped the order of some series components in a couple of places
 (e.g. I swapped the order of RT3 and R33).

Here are links to the design (the strips run vertically)

1) Component-side view.  Using the same labels as Thomeeque's v1.1 PDF.
http://www.imageshack.com/i/j8cs0wj

2) Component-side view.  Showing the values.
http://www.imageshack.com/i/nqhb58j

3) Component-side view, with "x-ray" through to the strips below.
http://www.imageshack.com/i/1fcvt5j

4) Strip-side view (mirror image of other views) showing where to make breaks (dark horizontal lines) in strips, and where to join
adjacent strips with blobs of solder (the ellipses).
Tip: Make all the breaks in the strips BEFORE soldering all components,
       and join adjacent strips with solder AFTER soldering all components.
http://www.imageshack.com/i/0hzxt0j

Note that the colors of the strips in 4) don't always match the colors in 3).  
That's not an error, it's just the coloring algorithm I used in the program that produced the pictures.

I will link to photos of my build later.
Title: Re: EM3207 (v1.1) - MN3207 based EHX Electric Mistress (9V) clone
Post by: DrAlx on July 23, 2013, 01:44:24 PM
One other thing I should mention is that my stripboard layout uses the opamps on IC1 and IC3 in different order to what is shown in Tomas' schematic and PCB.
This was to make a more compact layout.  That means the pin-outs in my build are a permutation of those in the Tomas' schematic.
In Tomas' schematic, the IC3 opamps are used in this order (IC3A, IC3B, IC3C, IC3D) but my stripboard layout uses them in reverse order (IC3D, IC3C, IC3B, IC3A).
Similarly for IC1.  

Here is my EM3207 stripboard build in a 1590BB. The range and rate pots haven't arrived yet, so I am using 2 fixed resistors for the moment (far right of pic):

(http://imageshack.com/a/img12/2091/h22m.jpg)


Title: Re: EM3207 (v1.1) - MN3207 based EHX Electric Mistress (9V) clone
Post by: DrAlx on July 24, 2013, 05:10:39 PM
And the messy solder back ...
(http://imageshack.com/a/img819/3629/yj41.jpg)
Title: Re: EM3207 (v1.1) - MN3207 based EHX Electric Mistress (9V) clone
Post by: DrAlx on July 24, 2013, 06:48:55 PM
And here's what it sounds like with those 2 resistors replacing the rate and range pots (roughly 50% on each).
First minute is with the filter matrix on (nice bell sounds from the harmonics  :)
Second minute with the sweep on.
It's a crazy tuning on the guitar (bottom E string tuned down to B)

https://soundcloud.com/alex-lawrow/em3207_flanger_demo (https://soundcloud.com/alex-lawrow/em3207_flanger_demo)

A  BIG THANK YOU to Tomas for making this cool circuit available to everyone.
Title: Re: EM3207 (v1.1) - MN3207 based EHX Electric Mistress (9V) clone
Post by: Scruffie on July 26, 2013, 08:07:01 PM
Great Vero layout! Don't use it anymore my self but sure a lot of guys are going to appreciate that.

Nice build too  :)
Title: Re: EM3207 (v1.1) - MN3207 based EHX Electric Mistress (9V) clone
Post by: DrAlx on July 27, 2013, 07:22:36 AM
Apologies. There is a mistake in image (4) of my original post with the stripboard design.
That's the image of the strip-side of the board, showing where to put the breaks and solder blobs.
In the process of taking a screenshot, I must have clicked on the program window and accidentally removed a strip break.
That's what caused the colors to mismatch, not my coloring algorithm as I first thought.

I have corrected this now and put the whole set of diagrams in a single 1600x1400 image here...

http://imageshack.com/a/img855/4543/mw48.jpg


Title: Re: EM3207 (v1.1) - MN3207 based EHX Electric Mistress (9V) clone
Post by: DrAlx on August 01, 2013, 07:07:54 AM
My pots finally arrived from Banzai so I finished my build and reset the trim-pots.
I previously set RT3 to zero to give quickest clock, and it was flanging but sounding quite phaser-like.
I have now set RT3 to give a maximum delay of 13 ms in filter matrix mode (which is larger than the
7.69 ms delay measured by Thomeeque on the vintage EM in filter-matrix mode) but I like the result.
I don't have an oscilloscope so I set RT3 as follows. I hope the method is useful to other people who want to set RT3 but don't have a scope.

1) Use filter-matrix mode with Range pot at maximum value (longest delay) and Color pot to maximum (maximum feedback).
2) Start with RT3 around 20% from zero.  Set RT1 so it is just short of causing self oscillation.
3) Make a short loud slap on the guitar neck.  The pedal should produce a sound that is similar to the sound
you get when you hold a ruler on the edge of a table and "twang it".  RT3 sets the pitch of the twang.   RT1 sets the decay of the twang.   It must not decay too quickly or you will have difficulty determining the pitch. The idea is to trim RT3 until the pitch of the twang matches a reference pitch.
4) I wanted a maximum flanger delay time of 13 ms, which corresponds to a twang with pitch of 1/0.013 = 77 Hz.
   You can use an online tone generator (http://onlinetonegenerator.com/) to give you a reference pitch.
   What I did instead was take a digital delay pedal with a delay of 13 ms and lots of repeats,
   and used that to produce a reference twang sound. I then toggled between the delay pedal and the EM3207, tweaking RT3 until the twang sounds had the same pitch.
5) Once RT3 is set, move RT1 away from the self-oscillation point until clock noise is acceptably low.  I like twangs to sound metallic but too metallic.

I recorded samples of the tweaked pedal here. 
This is the guitar into the EM3207 and then straight into a BR600 recorder with only a little reverb added and nothing else.

http://soundcloud.com/alex-lawrow/em3207-flanger-after-trimming
Title: Re: EM3207 (v1.1) - MN3207 based EHX Electric Mistress (9V) clone
Post by: DrAlx on August 01, 2013, 01:11:19 PM
Thomeeque, I have a question for you about component values.

I know that the BBD output needs a LPF with a cutoff frequency that is less than 1/2 the clock frequency
in order to avoid aliasing effects.  I have read that in practice the LPF cutoff frequency should be
even lower (less than 1/3 of the clock frequency).  See link to book extract at very bottom of this message.
Presumably that is because real world filters don't have a rectangular cutoff.

For the EM3207 I see there is an LPF on the BBD output formed by the parallel combination of
of (R12,R13,R14) = 2.23k and C7 = 680pF.  
I calculate the 3dB point for that RC filter to be about 100 kHz
which is 1/2 the 3207's maximum supported clock frequency of 200 kHz.
A clock frequency of 200 kHz gives the minimum supported BBD delay of 2.56 ms.

My question is this:  Shouldn't the LPF filter cutoff be determined by the minimum clock frequency
that is encountered during a sweep rather than the maximum clock frequency?
For example, let's say that at the bottom of the flange sweep the BBD delay is 10.24ms.
The clock is only running at 50kHz at that point, not 200kHz, so for that part of the sweep the BBD
requires an LPF with a much lower cutoff of 25 kHz, not 100 kHz.  Am I missing something here, or is there
some other reason why that bit of the circuit is using a 100kHz cutoff?

I increased C7 to 2.7nF to lower the LPF cutoff, and it does noticeably reduce the clock noise at the bottom of the sweep
but it also makes the flange feedback a little less strong, so RT1 needed tweaking to increase feedback level.
The strange thing is that I prefer the default C7 value of 680 pF, because there is a bit more treble in the sound
despite the louder clock noise.  So maybe aliasing effects contribute to the sound in a good way?

Here's the link to the BBD book extract:

http://books.google.co.uk/books?id=9_tkus_y8BQC&pg=PA194&lpg=PA194&dq=MN3207+clock+cancel&source=bl&ots=QyiGHC0Z7W&sig=pxqOY3-vjj8qvlzdRfBw_GV4XuE&hl=en&sa=X&ei=3Xf3UY3uFeHD7AbLvoEw&redir_esc=y#v=onepage&q=MN3207%20clock%20cancel&f=false


Title: Re: EM3207 (v1.1) - MN3207 based EHX Electric Mistress (9V) clone
Post by: Hemmel on August 01, 2013, 01:45:56 PM

http://imageshack.com/a/img855/4543/mw48.jpg


Hi DrAlx,

This looks very interesting to me cuz my brother is bugging me for an Electric Mistress. I was looking at your layouts and I'm wondering what are numbers 5 through 11 on the bottom-right layout ? You've identified 1-4 and 12,13 from bottom-left to bottom-right layouts, but not the other numbers....
Could you clarify please ?
Thanks !!!
Title: Re: EM3207 (v1.1) - MN3207 based EHX Electric Mistress (9V) clone
Post by: DrAlx on August 01, 2013, 02:52:56 PM
Thomeeque kindly produced a pdf document with detailed build instructions on page 1 of the thread.
Here's the link to his pdf:

http://thmq.mysteria.cz/em3207/build/EM3207_v1.1_Build_Instructions.pdf

My stripboard layout has the exact same component numbering and pad numbering as that document.
The only component value that is not up-to-date in that PDF is  C17.
Thomeeque recently posted than he now recommends 47pF instead of 22pF, so that's what I used.

(The 5,6,7,8,9) are the PAD numbers in Thomeeque's schematic.
They are to a double-pole double-throw (DPDT) switch that lets you toggle between flanger mode and filter-matrix mode.
The DPDT switch is wired like this

  6--O  O--7
  8--O  O--9
  5--O  O--6

10 and 11 are not needed.  If you want to experiment with different C17 values you can use them to place an extra cap there.
I didn't bother using them in by build.  I only marked them in my layout for sake of completeness.
Title: Re: EM3207 (v1.1) - MN3207 based EHX Electric Mistress (9V) clone
Post by: Hemmel on August 01, 2013, 03:06:07 PM
Oh yeah... that's me, whenever I see a thread that's 18 pages long I'm usually lazy and don't read it all before replying...  :-[

Thanks for clearing that up.

Now I need to find that MN3207 chip (neither Small Bear nor Tayda seem to have it)
Title: Re: EM3207 (v1.1) - MN3207 based EHX Electric Mistress (9V) clone
Post by: Scruffie on August 01, 2013, 03:07:11 PM
Oh yeah... that's me, whenever I see a thread that's 18 pages long I'm usually lazy and don't read it all before replying...  :-[

Thanks for clearing that up.

Now I need to find that MN3207 chip (neither Small Bear nor Tayda seem to have it)
Use a V3207 or BL3207, Smallbear has both, just different branded modern reproductions.
Title: Re: EM3207 (v1.1) - MN3207 based EHX Electric Mistress (9V) clone
Post by: Hemmel on August 01, 2013, 03:34:25 PM
Thanks Scruffie ! I tried googling for "MN3207 equivalent" but didn't find any  ???

Now if I put a 22pF on C17, then use pads 10 and 11 to connect a SPDT switch to add either a 22pF or a 47pF, wouldn't this provide a choice between 22, 44 and 69pF (more or less) ? I'm guessing I'd need an ON-OFF-ON SPDT ?

Here's what I mean :

(http://img22.imageshack.us/img22/825/h04p.png) (http://imageshack.us/photo/my-images/22/h04p.png/)

Would this be right ?
Title: Re: EM3207 (v1.1) - MN3207 based EHX Electric Mistress (9V) clone
Post by: DrAlx on August 01, 2013, 05:41:16 PM
Thanks Scruffie ! I tried googling for "MN3207 equivalent" but didn't find any  ???

Now if I put a 22pF on C17, then use pads 10 and 11 to connect a SPDT switch to add either a 22pF or a 47pF, wouldn't this provide a choice between 22, 44 and 69pF (more or less) ? I'm guessing I'd need an ON-OFF-ON SPDT ?

Here's what I mean :

(http://img22.imageshack.us/img22/825/h04p.png) (http://imageshack.us/photo/my-images/22/h04p.png/)

Would this be right ?

Yes. That's correct.  If you don't mind ordering from overseas, Banzai Music in Germany have both MN3207 and BL3207.  That's where I ordered all the ICs,  but their delivery costs may be too high for you.  It wasn't too much of an overhead for me because I'm in the UK and I ordered other parts at the same time (other ICs, the enclosure, 9mm alpha pots, and most of the foil caps).
Title: Re: EM3207 (v1.1) - MN3207 based EHX Electric Mistress (9V) clone
Post by: DrAlx on August 01, 2013, 06:55:10 PM
Hemmel, I have just uploaded version 2 of my stripboard layout.
It's pretty much the same layout but I moved some components to make things a little less cramped.
It will make for a slightly easier build.  The improved layout is here...

http://imageshack.com/a/img35/8502/xeaj.jpg

Title: Re: EM3207 (v1.1) - MN3207 based EHX Electric Mistress (9V) clone
Post by: Hemmel on August 02, 2013, 02:00:12 PM
Thanks DrAlx !

BTW, I'm trying to figure how I could setup that switch on C17 so that once boxed, instead of the switch going 69pF - 22pF - 44pF from left to right, it could go 22 - 44 - 69 (or 69 - 44 - 22).
If this setup needs another kind of switch it's ok since I haven't bought any yet.

Any ideas ?
Title: Re: EM3207 (v1.1) - MN3207 based EHX Electric Mistress (9V) clone
Post by: DrAlx on August 02, 2013, 06:32:44 PM
Thanks DrAlx !

BTW, I'm trying to figure how I could setup that switch on C17 so that once boxed, instead of the switch going 69pF - 22pF - 44pF from left to right, it could go 22 - 44 - 69 (or 69 - 44 - 22).
If this setup needs another kind of switch it's ok since I haven't bought any yet.

Any ideas ?

I thought I found a way to wire the switch so that one throw would add capacitance in parallel to increase overall capacitance and the other throw would add capacitance in series to lower overall capacitance but my calculations were wrong.

To be honest I am not sure of the benefit of having the cap switchable since
you may need to retrim one of the pots when you switched caps.
As Thomeeque says, 22 pF isn't recommended because the effect won't sweep properly.
The original idea was to use that low value to overclock the delay chip, but there is a fundamental limitation to the
speed that you can clock that chip. Overclocking will cause it not shift charge effectively between buckets.
As I understand it, that would cause the signal to get weaker as it goes through the delay line, and also smear itself out
to some extent because charge it not transferred fully between buckets..


Title: Re: EM3207 (v1.1) - MN3207 based EHX Electric Mistress (9V) clone
Post by: DrAlx on August 18, 2013, 04:20:53 PM
I'm working on a vero layout to try and fit a TZF flanger into a 1590BB (using the EM3207 as a starting point).  While going over my vero layout for the EM3207, I realized I got the values for RT2 and RT3 the wrong way around in my layout and build.  They can still be trimmed OK of course.  In any case, i have put a corrected layout (with switch wiring and alignment procedure) in a single image here...

http://www.imageshack.com/i/5njet6j

BTW, has anyone tried Thomas's TZF add-on for the EM3207, and if so were there any heterodyning issues ?
Title: Re: EM3207 (v1.1) - MN3207 based EHX Electric Mistress (9V) clone
Post by: Hemmel on August 18, 2013, 04:24:29 PM
I get "lost image" from that link ...
Title: Re: EM3207 (v1.1) - MN3207 based EHX Electric Mistress (9V) clone
Post by: Scruffie on August 18, 2013, 06:35:32 PM
I'm working on a vero layout to try and fit a TZF flanger into a 1590BB (using the EM3207 as a starting point).  While going over my vero layout for the EM3207, I realized I got the values for RT2 and RT3 the wrong way around in my layout and build.  They can still be trimmed OK of course.  In any case, i have put a corrected layout (with switch wiring and alignment procedure) in a single image here...

http://www.imageshack.com/i/5njet6j

BTW, has anyone tried Thomas's TZF add-on for the EM3207, and if so were there any heterodyning issues ?
Yes, No (although that is not necessarily gunna be the same for each build) and it didn't work that well.

I think the EM is too 'light' on the flange for it, i'd go with an MXR-117 to try it.
Title: Re: EM3207 (v1.1) - MN3207 based EHX Electric Mistress (9V) clone
Post by: DrAlx on August 18, 2013, 09:09:52 PM
I get "lost image" from that link ...
Strange. Try this instead...

http://imageshack.com/a/img203/7361/jet6.jpg
Title: Re: EM3207 (v1.1) - MN3207 based EHX Electric Mistress (9V) clone
Post by: DrAlx on August 18, 2013, 09:47:34 PM
I'm working on a vero layout to try and fit a TZF flanger into a 1590BB (using the EM3207 as a starting point).  While going over my vero layout for the EM3207, I realized I got the values for RT2 and RT3 the wrong way around in my layout and build.  They can still be trimmed OK of course.  In any case, i have put a corrected layout (with switch wiring and alignment procedure) in a single image here...

http://www.imageshack.com/i/5njet6j

BTW, has anyone tried Thomas's TZF add-on for the EM3207, and if so were there any heterodyning issues ?
Yes, No (although that is not necessarily gunna be the same for each build) and it didn't work that well.

I think the EM is too 'light' on the flange for it, i'd go with an MXR-117 to try it.

Thanks for the info Scruffie. I am wondering what you mean my 'light'.  Are you talking about having a maximum delay time that is too small, or something else?
I was going to tweak quite a few other things (i.e. put identical LPFs in both delay paths).  I'm thinking the 2 paths ought to be as similar as possible apart from the different delays.
I am wondering if one path is heavily filtered (as in the separate TZF add-on) but the other one isn't (as in the regular EM) then phases at the zero point might not all cancel properly.
Maybe the effect is too small to make any difference.  If range of delays is a problem then I'll have to go back to the drawing board on this.
Title: Re: EM3207 (v1.1) - MN3207 based EHX Electric Mistress (9V) clone
Post by: Scruffie on August 19, 2013, 04:06:46 PM
I'm working on a vero layout to try and fit a TZF flanger into a 1590BB (using the EM3207 as a starting point).  While going over my vero layout for the EM3207, I realized I got the values for RT2 and RT3 the wrong way around in my layout and build.  They can still be trimmed OK of course.  In any case, i have put a corrected layout (with switch wiring and alignment procedure) in a single image here...

http://www.imageshack.com/i/5njet6j

BTW, has anyone tried Thomas's TZF add-on for the EM3207, and if so were there any heterodyning issues ?
Yes, No (although that is not necessarily gunna be the same for each build) and it didn't work that well.

I think the EM is too 'light' on the flange for it, i'd go with an MXR-117 to try it.

Thanks for the info Scruffie. I am wondering what you mean my 'light'.  Are you talking about having a maximum delay time that is too small, or something else?
I was going to tweak quite a few other things (i.e. put identical LPFs in both delay paths).  I'm thinking the 2 paths ought to be as similar as possible apart from the different delays.
I am wondering if one path is heavily filtered (as in the separate TZF add-on) but the other one isn't (as in the regular EM) then phases at the zero point might not all cancel properly.
Maybe the effect is too small to make any difference.  If range of delays is a problem then I'll have to go back to the drawing board on this.

I mean in general sound, this isn't as 'Jetty' as some flangers, more musical chorusey. My opinion anyway and that such a flanger might help with the harmonics needed to get pleasing through zero flanging...

Putting the zero add on out of phase might help the sound a bit perhaps?
Title: Re: EM3207 (v1.1) - MN3207 based EHX Electric Mistress (9V) clone
Post by: Hemmel on August 26, 2013, 01:44:27 PM
DrAlx's stripboard template asks for 27*23, however the only stripboards I found have 20 strips max. Does anyone know where I could get bigger stripboards ?
Title: Re: EM3207 (v1.1) - MN3207 based EHX Electric Mistress (9V) clone
Post by: DrAlx on August 27, 2013, 04:24:51 PM
DrAlx's stripboard template asks for 27*23, however the only stripboards I found have 20 strips max. Does anyone know where I could get bigger stripboards ?

27 holes is 2.7 inches.   So search with inches in the size     i.e. use a search term like

    Stripboard 4''

You get lots of hits on amazon.  e.g.

http://www.amazon.com/Prototype-Stripboard-2400hole-Phenolic-Pitch/dp/B008CI1Z6U/ref=sr_1_10?ie=UTF8&qid=1377634912&sr=8-10&keywords=stripboard+4%27%27

and even eBay.  e.g. from Canada ...

http://www.ebay.co.uk/itm/Phenolic-Stripboard-4-x8-101-205-mm-3200Hole-Prototype-PCB-Veroboard-/151030620176?pt=LH_DefaultDomain_2&hash=item232a206010
Title: Re: EM3207 (v1.1) - MN3207 based EHX Electric Mistress (9V) clone
Post by: DrAlx on October 06, 2013, 06:06:05 AM
I finally built my veroboard TZF.  It is based on Thomeeque's EM3207 and TZF mod with some differences.

1) The BBDs are biased locally (i.e. with separate bias to the audio op-amps).
2) A 2 pole active LPF before the BBDs.
3) 3 pole active LPFs after each BBD.  The filter characteristics are different to Thomeques.  I have ~15 kHz cutoff.
4) A DPDT switch to give the option of additive/subtractive flanging.
5) A DPDT centre-zero switch to give regular flanging / TZF flanging / or plain vibrato.
6) Regardless of flanging mode, the 2 signal paths always go through LPFs, so the 2 signal paths are balanced.

I don't have an oscilloscope and haven't checked for unity gain yet so I may tweak things further.
It should just about fit a 1590BB if I file down the input/output jack sockets a little bit.

From the pics you'll see I used adhesive copper foil as a ground plane.  There is a clear layer of adhesive-backed plastic on top of it to provide electrical insulation from the bare wires on the top, and to prevent accidental connections to component legs..
I will post the whole project instructions and the procedure for making the ground plane at some point in a new thread.  In the mean time, here is a soundclip showing the subtractive and additive TZF.  There's just a fuzz box before the flanger.

soundcloud.com/alex-lawrow/my-through-zero-flanger

and some pics

http://imageshack.com/a/img801/2586/yjo4.jpg
http://imageshack.com/a/img855/9305/otz6.jpg
http://imageshack.com/a/img856/6966/3tni.jpg
http://imageshack.com/a/img203/6876/1pv5.jpg

Title: Re: EM3207 (v1.1) - MN3207 based EHX Electric Mistress (9V) clone
Post by: StephenGiles on October 06, 2013, 07:35:58 AM
Great stuff!
Title: Re: EM3207 (v1.1) - MN3207 based EHX Electric Mistress (9V) clone
Post by: GodSaveMetal on October 06, 2013, 05:48:48 PM
I finally built my veroboard TZF.  It is based on Thomeeque's EM3207 and TZF mod with some differences.

1) The BBDs are biased locally (i.e. with separate bias to the audio op-amps).
2) A 2 pole active LPF before the BBDs.
3) 3 pole active LPFs after each BBD.  The filter characteristics are different to Thomeques.  I have ~15 kHz cutoff.
4) A DPDT switch to give the option of additive/subtractive flanging.
5) A DPDT centre-zero switch to give regular flanging / TZF flanging / or plain vibrato.
6) Regardless of flanging mode, the 2 signal paths always go through LPFs, so the 2 signal paths are balanced.

I don't have an oscilloscope and haven't checked for unity gain yet so I may tweak things further.
It should just about fit a 1590BB if I file down the input/output jack sockets a little bit.

From the pics you'll see I used adhesive copper foil as a ground plane.  There is a clear layer of adhesive-backed plastic on top of it to provide electrical insulation from the bare wires on the top, and to prevent accidental connections to component legs..
I will post the whole project instructions and the procedure for making the ground plane at some point in a new thread.  In the mean time, here is a soundclip showing the subtractive and additive TZF.  There's just a fuzz box before the flanger.

soundcloud.com/alex-lawrow/my-through-zero-flanger

and some pics

http://imageshack.com/a/img801/2586/yjo4.jpg
http://imageshack.com/a/img855/9305/otz6.jpg
http://imageshack.com/a/img856/6966/3tni.jpg
http://imageshack.com/a/img203/6876/1pv5.jpg



PLEASE POST HERE MAN AN INSTRUTIVE HOW TO MAKE THAT!!!!!!!!!!!!

I STAY TUNED!!!!!!!!!!
Title: Re: EM3207 (v1.1) - MN3207 based EHX Electric Mistress (9V) clone
Post by: DrAlx on October 07, 2013, 06:45:07 PM
I have just done an Instructable for my method of applying a ground plane to strip-board.
I'm quite new to this whole forum thing so I don't know the best place to share this info.
Here's the link.

http://www.instructables.com/id/Method-of-applying-a-copper-ground-plane-to-strip-/
Title: Re: EM3207 (v1.1) - MN3207 based EHX Electric Mistress (9V) clone
Post by: GodSaveMetal on October 08, 2013, 12:46:11 AM
I have just done an Instructable for my method of applying a ground plane to strip-board.
I'm quite new to this whole forum thing so I don't know the best place to share this info.
Here's the link.

http://www.instructables.com/id/Method-of-applying-a-copper-ground-plane-to-strip-/


Excelent man; fine details and TIPS, and please the layout of that  ??? you post here  ??? please man your layout and all to make one!  :icon_wink:
Title: Re: EM3207 (v1.1) - MN3207 based EHX Electric Mistress (9V) clone
Post by: DrAlx on October 11, 2013, 09:56:17 PM
I have put a link to my veroboard TZF build instructions in a new thread.
Please use that thread for discussion and comments

http://www.diystompboxes.com/smfforum/index.php?topic=104694.0
Title: Re: EM3207 (v1.1) - MN3207 based EHX Electric Mistress (9V) clone
Post by: peterg on December 16, 2013, 04:08:28 PM
Can someone post a verified schematic for the MN3207 based EHX Electric Mistress (9V) clone?
Title: Re: EM3207 (v1.1) - MN3207 based EHX Electric Mistress (9V) clone
Post by: Dave W on December 17, 2013, 05:23:24 PM
Can someone post a verified schematic for the MN3207 based EHX Electric Mistress (9V) clone?
page 1, post 1 of this thread. its all there…  ;)
Title: Re: EM3207 (v1.1) - MN3207 based EHX Electric Mistress (9V) clone
Post by: DrAlx on March 23, 2014, 10:18:55 PM
Here is how you can improve the sweep ratio of the EM3207 Electric Mistress if it is poor (this is quite likely as I explain below !!!).

Note that changing the clock capacitor or adjusting the clock trim-pot cannot fix a poor sweep ratio.  You need to do what I describe here.
The following modification let me achieve a sweep ratio of about 20:1  (delay range of 0.66 ms to 13.3 ms) compared to the very poor 4:1 ratio I had before.
Note that you should not confuse the range in "filter-matrix" mode with the dynamic "sweep" range.  
They are not the same and in fact the following modification will not change the behavior of filter-matrix mode at all.

Here's the modification:   Replace R24 (30k) and R26 (10k) by a single 100k multi-turn (precision) trim-pot.
Pins 1 and 2 of the trim-pot should replace R24, and pins 2 and 3 should replace R26.

This effectively gives us the ability to trim the ratio of R24 to R26.
To maximize the sweep range, follow this procedure:

=======================================
First tune "filter-matrix" mode as follows:

In filter-matrix mode, put the "Rate" pot at minimum (to avoid LFO supply wobble) and put the "Range" pot at maximum.
Then adjust the clock-trim pot to give a BBD delay of 10 ms. (Each BBD clock line should have a period of about 19.5 ms).
The end result of this (for my build) was that filter matrix BBD delay can go from 1.3 ms to 10 ms.  (A ratio of 7.5 : 1).
Note that this ratio in filter-matrix mode will not change much with the clock trim, and should always be around the 7:1 area.
The main point of tuning filter-matrix mode first, is to make sure the clock is not set too fast.
We need to allow it to run slow to achieve a big range in sweep mode.

Now go to "sweep" mode and tune it as follows:

1) Put the "Rate" pot at minimum (i.e. slowest sweep).  This is important because you need to minimize the effect of C15 (which decreases the triangle wave amplitude for fast sweeps).
2) Put the "Range" pot at maximum.
3) Trim the newly added pot so that the sweep goes as high as possible without breaking up or "popping" at the top.
4) Put the "Range" pot at minimum and confirm the sweep still does not break up or pop at the top.  If it does, then trim further.
(The whole point is that there should be no popping, regardless of how the "Range" pot is set).
5) That's it.

=======================================

Explanation:

The LFO design of the EM3207 has a sweep ratio that is VERY sensitive to component tolerances (even using 1% resistors) and supply voltage.  I found this out first hand after building two of them and noticing one had poorer sweep ratio than the other, and that it could not be fixed by the clock trim.

I did a Monte Carlo analysis of the original EM3207 (without my trim-pot mod) using a 9V LFO supply voltage, and random +/- 1% errors on the 7 fixed LFO resistors.  I found significant variation in the maximum sweep ratio.  Things are worse if you run the LFO off a 10V supply rather than 9V (which is what the resistor values were designed for), and the analysis shows it is then possible to have an unlucky combination of resistor errors that cause the sweep to "pop" at the top, and it will not be possible to trim this out with the clock trimmer.  This happened in 10% of cases when running at 10V.  (You will be able to trim it out using the mod described here of course).

Title: Re: EM3207 (v1.1) - MN3207 based EHX Electric Mistress (9V) clone
Post by: DrAlx on March 24, 2014, 10:17:47 AM
My Monte Carlo analysis and thinking was badly flawed :-[.
The modification works but the explanation is complete rubbish.  I was wrong about the effect of tolerances being as extreme as I first thought, and the "popping" on 10V supply.  :-[ :-[
I failed to account for the range pot and how it is wired up and that was a mistake.
I have reworked things and finally managed to get an analysis that matches what I observed in practice :)
Here's an editable spread sheet with correct results.  You need to scroll to the very top.
Basically I calculate the ratio of max and min control voltages applied to the comparator.

http://1drv.ms/1fbfI0h

Edit the resistor values in red, and Excel will generate 999 other random variations and look at the distribution of sweep ratios.
The results are in green.

It seems that the sweep ratio for the 9V Electric Mistress is actually quite small by design (in the range of 3:1 to 4:1).
It is nothing to do with a BBD limitation, it is just the nature of the LFO.  So there was nothing wrong with my builds afterall. :)
I can't comment on the really old 18V versions of the EM, as that had different LFO.

For some reason I was expecting the range to be more like the 7:1 range in filter matrix mode, or even larger. When I saw one build had sweep ratio of 3:1 rather than 4:1 (which I still think is a big difference) I tried to see if I could fix it.
In any case, it shows that with a slight tweak, you can take the LFO for the EM and use it to produce pretty large flanger sweeps.
Title: Re: MN3007 (v1.1)
Post by: kowe90 on April 28, 2014, 03:08:41 PM
Hi
i finished the electric mistress based on mn3007 v1.1 layout, the pedal "work" i get dry signal but i don't have any effect, any pot affect the signal.
I use a 15v 5w zener, i have checked all the components and solder but i can't found the error.
i don't know how to make it work properly, i need help!!!! :)
thanks
Title: Re: MN3007 (v1.1)
Post by: Govmnt_Lacky on April 29, 2014, 07:15:24 AM
Hi
i finished the electric mistress based on mn3007 v1.1 layout, the pedal "work" i get dry signal but i don't have any effect, any pot affect the signal.
I use a 15v 5w zener, i have checked all the components and solder but i can't found the error.
i don't know how to make it work properly, i need help!!!! :)
thanks

Go here and repost:

http://www.diystompboxes.com/smfforum/index.php?topic=29816.0
Title: Re: EM3207 (v1.1) - MN3207 based EHX Electric Mistress (9V) clone
Post by: Dave W on April 29, 2014, 12:44:06 PM
help is here but we need a lot more info. for now, get your schematic and check all the Vs. the correct Vs are posted somewhere here (do a search). then get an audio probe, signal source (a guitar will do but a signal generator is preferred) & an amp and go to it. also…. remember this has to be biased properly.
no effect at all is usually an easy fix. its the intermittent problems that are a PITA.
there are a bunch of us who have developed and successfully built this and it is one of the easier flangers to build and "get right". read the 3007 retrofit thread. any info you need is probably all in there.
 8)  8)  8)
Title: Re: MN3007 (v1.1)
Post by: DrAlx on April 29, 2014, 08:45:44 PM
Hi
i finished the electric mistress based on mn3007 v1.1 layout, the pedal "work" i get dry signal but i don't have any effect, any pot affect the signal.
I use a 15v 5w zener, i have checked all the components and solder but i can't found the error.
i don't know how to make it work properly, i need help!!!! :)
thanks

I haven't found an "MN3007 v1.1" layout, only the "MN3207 v.1.1" layout.
I'm sorry if this is  a stupid question, but did you rework Thomeeque's MN3207 layout for the MN3007,
or did you simply try and substitute the MN3007 for the MN3207 and increase the supply voltage to 15V?
Title: EM3007 v 1.1 link
Post by: Dave W on April 29, 2014, 10:06:14 PM
here ya' go….
http://www.diystompboxes.com/smfforum/index.php?topic=91981.msg798618#msg798618
reply #81
Title: Re: MN3007 (v1.1)
Post by: kowe90 on May 01, 2014, 12:35:39 PM
hi
it works right now, i need to adjust it but it works :)
the best sound at 15v, at 9v it is a little bit noisy.
Thank for your support
Title: Re: MN3007 (v1.1)
Post by: Govmnt_Lacky on May 01, 2014, 12:39:20 PM
hi
it works right now, i need to adjust it but it works :)
the best sound at 15v, at 9v it is a little bit noisy.
Thank for your support

It is ALWAYS good to share the details of the repair so others can learn.  ;)
Title: Re: MN3007 (v1.1)
Post by: kowe90 on May 02, 2014, 08:51:35 AM
hi
it works right now, i need to adjust it but it works :)
the best sound at 15v, at 9v it is a little bit noisy.
Thank for your support

It is ALWAYS good to share the details of the repair so others can learn.  ;)
Bad solder  :icon_redface: and the pin 2 of the 1M pot is not connected in this layout, i see other schematic with this pin connected to the first pin
Title: Re: EM3207 (v1.1) - MN3207 based EHX Electric Mistress (9V) clone
Post by: armdnrdy on May 02, 2014, 01:44:26 PM
Here is how you can improve the sweep ratio of the EM3207 Electric Mistress if it is poor (this is quite likely as I explain below !!!).

Here's the modification:   Replace R24 (30k) and R26 (10k) by a single 100k multi-turn (precision) trim-pot.
Pins 1 and 2 of the trim-pot should replace R24, and pins 2 and 3 should replace R26.

This effectively gives us the ability to trim the ratio of R24 to R26.


Question for DrAlx:

I'm working on a "version 5" build using an original R5106 that I came across.

I would like to implement your increased sweep mod, but I'm having a bit of trouble interpreting your description as to the placement of the 100K trimmer.

I worked on a drawing to replace the 30K and the 10K (version 5 = 11K) resistors with the 100K trimmer as described, (Pins 1 and 2 of the trim-pot should replace R24, and pins 2 and 3 should replace R26.) but this configuration makes a direct connection between the two op amp outputs with no resistance between them.

I worked up two other options...can you clue me in to the correct way to connect the trimmer?

Thanks....

LFO 1:
(https://dl.dropboxusercontent.com/u/53299166/DIYstompboxes/LFO%201.jpg)

LFO 2:
(https://dl.dropboxusercontent.com/u/53299166/DIYstompboxes/LFO%202.jpg)
Title: Re: EM3207 (v1.1) - MN3207 based EHX Electric Mistress (9V) clone
Post by: DrAlx on May 06, 2014, 02:14:05 PM
Here is how you can improve the sweep ratio of the EM3207 Electric Mistress if it is poor (this is quite likely as I explain below !!!).

Here's the modification:   Replace R24 (30k) and R26 (10k) by a single 100k multi-turn (precision) trim-pot.
Pins 1 and 2 of the trim-pot should replace R24, and pins 2 and 3 should replace R26.

This effectively gives us the ability to trim the ratio of R24 to R26.


Question for DrAlx:

I'm working on a "version 5" build using an original R5106 that I came across.

I would like to implement your increased sweep mod, but I'm having a bit of trouble interpreting your description as to the placement of the 100K trimmer.

I worked on a drawing to replace the 30K and the 10K (version 5 = 11K) resistors with the 100K trimmer as described, (Pins 1 and 2 of the trim-pot should replace R24, and pins 2 and 3 should replace R26.) but this configuration makes a direct connection between the two op amp outputs with no resistance between them.

Looking at this schematic below from the Electric Mistress Mystery Page, the mod would involve removing the fixed 30k and the 11k resistors and using a 100k pot as follows.

The left pin of the pot goes to pin1 of the LM324.
The right pin of the pot goes to pin 8 of the LM324.
The middle pin of the pot goes to pin 3 of the LM324

Your first LFO pic is almost right (but the middle pin of the pot should go to pin 3 only).
One thing to point out is that I would use an internal trim-pot for this mod rather than a pot.
The reason being that if you try and generate too big a triangle wave, then the comparator part of the circuit that generates the clock will stop at the top of the sweep.
This will give an audible pop and then silence at the top part of the sweep (a "drop-out").

If I were going to expose this mod as an extra control pot on the front of the effects box (called "RATIO" or something),
then instead of connecting the left pin of this new RATIO pot directly to pin 1 of the LM324, I would make that connection through an extra resistor.  
That will stop the sweep from trying to go too high and causing a drop-out.
I couldn't tell you what resistor to use, and I would probably use an extra trim pot for it (adjustable from 0 to 100k say).
I'd set the trim pot at zero and gradually increase it until the SWEEP RATIO pot stopped giving "drop outs" at the top of the sweep.

(http://www.metzgerralf.de/elekt/stomp/mistress/images/deluxe-electric-mistress-v5-schematic.gif)


Title: Re: EM3207 (v1.1) - MN3207 based EHX Electric Mistress (9V) clone
Post by: armdnrdy on May 06, 2014, 02:33:28 PM
Thanks for taking the time to clarify and explain.

I just could not wrap my head around the proper connections!

I plan to use a trimmer (TR5) as you suggested in your original post about this mod.

Thanks again.
Title: Re: EM3207 (v1.1) - MN3207 based EHX Electric Mistress (9V) clone
Post by: digital-91 on June 04, 2014, 11:02:09 AM
Hi Tomas and guys in this thread.

I could build my EM3207 successfully.
I love this sound much !

Many informations and instructions in this thread helped me a lot.
I would like to say thank you all and report some photos of my build.

<photos>

I made PCB pattern for myself, because I wanted more thick PCB lines and some additional pads.
But, it is almost same as PDF's layout.
(http://cdn-ak.f.st-hatena.com/images/fotolife/d/digital-91/20140511/20140511211125.jpg)

completed PCB.
(http://cdn-ak.f.st-hatena.com/images/fotolife/d/digital-91/20140523/20140523232445.jpg)

I used 1590N1 case. It is a little bit bigger than 1590B size.
(http://cdn-ak.f.st-hatena.com/images/fotolife/d/digital-91/20140604/20140604012023.jpg)

finished my EM3207. Both mode (flanger and filter matrix) works well.
(http://cdn-ak.f.st-hatena.com/images/fotolife/d/digital-91/20140604/20140604224151.jpg)


<differences>

Basically, I followed PDF(v1.1) instruction, but I made some differences from PDF.


<alignment>

I don't have an osiloscope, so I adjusted three trimpots like this.

I'm not sure that I could tune it fine.
But I think I could get my best EM3207 sound.

Thanks  :)
Title: Re: EM3207 (v1.1) - MN3207 based EHX Electric Mistress (9V) clone
Post by: GodSaveMetal on June 04, 2014, 03:36:32 PM
Hi Tomas and guys in this thread.

I could build my EM3207 successfully.
I love this sound much !

Many informations and instructions in this thread helped me a lot.
I would like to say thank you all and report some photos of my build.

<photos>

I made PCB pattern for myself, because I wanted more thick PCB lines and some additional pads.
But, it is almost same as PDF's layout.
(http://cdn-ak.f.st-hatena.com/images/fotolife/d/digital-91/20140511/20140511211125.jpg)

completed PCB.
(http://cdn-ak.f.st-hatena.com/images/fotolife/d/digital-91/20140523/20140523232445.jpg)

I used 1590N1 case. It is a little bit bigger than 1590B size.
(http://cdn-ak.f.st-hatena.com/images/fotolife/d/digital-91/20140604/20140604012023.jpg)

finished my EM3207. Both mode (flanger and filter matrix) works well.
(http://cdn-ak.f.st-hatena.com/images/fotolife/d/digital-91/20140604/20140604224151.jpg)


<differences>

Basically, I followed PDF(v1.1) instruction, but I made some differences from PDF.
  • D3 -> 10V/1W (couldn't obtain 10V/5W zener)
  • RT3 -> 30K (couldn't obtain 22K trimpot)
  • R18 -> 12k (for better wet/dry balance)
  • C17 -> 47pF (clock cap. changed from 22pF)
  • I added additional switch for changing clock cap value with using PAD CC(PAD 10 and 11).


<alignment>

I don't have an osiloscope, so I adjusted three trimpots like this.
  • 1. Adjusting RT2(100k, BIAS) by a circuit tester.
    voltage pin3 of MN3207 should be 0.42 + 0.54*VCC (V)
  • 2. Adjusting RT3(22k, CLOCK) by my ear.
    I believe I could get my best sound.
  • 3. Adjusting RT1(10k, FEEDBACK) by my ear.
    I set the trim before oscillation when the COLOR pot MAX.

I'm not sure that I could tune it fine.
But I think I could get my best EM3207 sound.

Thanks  :)

Please man post your LAY, PCB an connections, all you have, I love that pads!!!!! please man!!!
Title: Re: EM3207 (v1.1) - MN3207 based EHX Electric Mistress (9V) clone
Post by: digital-91 on June 05, 2014, 08:39:30 AM
Hi, Roberto.

OK, I'll share my PCB pattern here.

First of all, I create my PCB layout with referring to EM3207_v1.1_Build_Instructions.pdf.
Thanks Tomas.

PCB pattern file is here. em3207_pcb_pattern.xps. It is zipped.
https://anonfiles.com/file/5da23578c14c7fd217e1beb0c3effbaa (https://anonfiles.com/file/5da23578c14c7fd217e1beb0c3effbaa)

There are 12 short jumpers. see red lines.
(http://cdn-ak.f.st-hatena.com/images/fotolife/d/digital-91/20140512/20140512235204.png)

I did it like this.
(http://cdn-ak.f.st-hatena.com/images/fotolife/d/digital-91/20140512/20140512235227.jpg)

And parts layout is here.
(http://cdn-ak.f.st-hatena.com/images/fotolife/d/digital-91/20140512/20140512235316.png)

There are 3 long jumpers. see red lines.
(http://cdn-ak.f.st-hatena.com/images/fotolife/d/digital-91/20140513/20140513234452.png)

I did it like this.
(http://cdn-ak.f.st-hatena.com/images/fotolife/d/digital-91/20140513/20140513234538.jpg)


I hope this help.
Thanks.
Title: Re: EM3207 (v1.1) - MN3207 based EHX Electric Mistress (9V) clone
Post by: GodSaveMetal on June 05, 2014, 07:27:21 PM
Please man the lay or your PCB pattern not compatible!! would you post in other format or photo format or PDF?; thanks for your help!
Title: Re: EM3207 (v1.1) - MN3207 based EHX Electric Mistress (9V) clone
Post by: digital-91 on June 06, 2014, 07:26:34 AM
Hi,

If you are using windows pc, you can view .xps format without difficulties.
But, I transformed it to pdf format.

Follow this link to download.
http://www.filedropper.com/em3207pcbpattern (http://www.filedropper.com/em3207pcbpattern)

Click "Download This File", file name is em3207_pcb_pattern.zip.
This zip file contains .xps and .pdf both.

 ;)
Title: Re: EM3207 (v1.1) - MN3207 based EHX Electric Mistress (9V) clone
Post by: GodSaveMetal on June 06, 2014, 05:16:23 PM
Great!!!!! THANKS man I see the PATTERN in PDF archive.
Title: Re: EM3207 (v1.1) - MN3207 based EHX Electric Mistress (9V) clone
Post by: armdnrdy on June 07, 2014, 10:54:02 AM
Hi,

If you are using windows pc, you can view .xps format without difficulties.
But, I transformed it to pdf format.

Follow this link to download.
http://www.filedropper.com/em3207pcbpattern (http://www.filedropper.com/em3207pcbpattern)

Click "Download This File", file name is em3207_pcb_pattern.zip.
This zip file contains .xps and .pdf both.


 ;)


Comes up as broken link.
Title: Re: EM3207 (v1.1) - MN3207 based EHX Electric Mistress (9V) clone
Post by: digital-91 on June 08, 2014, 08:25:31 AM
>Comes up as broken link.

Now, I checked the link, though, it was still alive.
Can't you see that link ?
Title: Re: EM3207 (v1.1) - MN3207 based EHX Electric Mistress (9V) clone
Post by: armdnrdy on June 08, 2014, 09:28:06 AM

Follow this link to download.
http://www.filedropper.com/em3207pcbpattern (http://www.filedropper.com/em3207pcbpattern)


Yes I can see it...but when I click on the link it takes me to a broken link page.
Title: Re: EM3207 (v1.1) - MN3207 based EHX Electric Mistress (9V) clone
Post by: digital-91 on June 08, 2014, 12:00:06 PM
>Yes I can see it...but when I click on the link it takes me to a broken link page.

I uploaded again, em3207_pcb_plus_a.zip.
https://anonfiles.com/file/39522015fb69bdb7a7457d8ab045cf71

 :D
Title: Re: EM3207 (v1.1) - MN3207 based EHX Electric Mistress (9V) clone
Post by: GodSaveMetal on June 10, 2014, 04:54:33 PM
<differences>

Basically, I followed PDF(v1.1) instruction, but I made some differences from PDF.
  • D3 -> 10V/1W (couldn't obtain 10V/5W zener)
  • RT3 -> 30K (couldn't obtain 22K trimpot)
  • R18 -> 12k (for better wet/dry balance)
  • C17 -> 47pF (clock cap. changed from 22pF)
  • I added additional switch for changing clock cap value with using PAD CC(PAD 10 and 11).


<alignment>

I don't have an osiloscope, so I adjusted three trimpots like this.
  • 1. Adjusting RT2(100k, BIAS) by a circuit tester.
    voltage pin3 of MN3207 should be 0.42 + 0.54*VCC (V)
  • 2. Adjusting RT3(22k, CLOCK) by my ear.
    I believe I could get my best sound.
  • 3. Adjusting RT1(10k, FEEDBACK) by my ear.
    I set the trim before oscillation when the COLOR pot MAX.

I'm not sure that I could tune it fine.
But I think I could get my best EM3207 sound.

Thanks  :)

You say that C17 have to change to a value of 47pF, and add a toggle switch to change that values; what values you use? and how you connected it to the pads 10 and 11?

Thanks man!!!
Title: Re: EM3207 (v1.1) - MN3207 based EHX Electric Mistress (9V) clone
Post by: digital-91 on June 11, 2014, 08:05:32 AM
Hi,

You say that C17 have to change to a value of 47pF, and add a toggle switch to change that values; what values you use? and how you connected it to the pads 10 and 11?

Thanks man!!!

See this photo, first.
(http://cdn-ak.f.st-hatena.com/images/fotolife/d/digital-91/20140611/20140611213333.png)

I changed C17 from 22pF to 47pF because I read this comment.
http://www.diystompboxes.com/smfforum/index.php?topic=91981.msg896276#msg896276 (http://www.diystompboxes.com/smfforum/index.php?topic=91981.msg896276#msg896276)

And I'm using a SPDT (on-off-on) switch and 22pF and 47pF capacitors, and

This additional SPDT switch and 2 caps mod is optional,
EM3207 works fine without this mod, you know.

I hope you enjoy this.

 :)
Title: Re: EM3207 (v1.1) - MN3207 based EHX Electric Mistress (9V) clone
Post by: GodSaveMetal on June 11, 2014, 03:25:05 PM
Great digital-91, thanks man !!!!!!!!!!!!!!!!!!
Title: Re: EM3207 (v1.1) - MN3207 based EHX Electric Mistress (9V) clone
Post by: armdnrdy on June 11, 2014, 03:45:32 PM
>Yes I can see it...but when I click on the link it takes me to a broken link page.

I uploaded again, em3207_pcb_plus_a.zip.
https://anonfiles.com/file/39522015fb69bdb7a7457d8ab045cf71

 :D

Got it now! Thank you!
Title: Re: EM3207 (v1.1) - MN3207 based EHX Electric Mistress (9V) clone
Post by: digital-91 on June 13, 2014, 12:48:48 PM
Hi, Roberto and Larry,

I put photos and PCB pattern jpg here.
http://sutonpu.hatenablog.jp/entry/2014/06/11/211409 (http://sutonpu.hatenablog.jp/entry/2014/06/11/211409)

Yes, I finally succeeded in transforming from .xps to .jpg. :-)
I takes a long time to find out the way ...

good luck.
Title: Re: EM3207 (v1.1) - MN3207 based EHX Electric Mistress (9V) clone
Post by: armdnrdy on June 13, 2014, 01:19:03 PM
Thank you!
Title: Re: EM3207 (v1.1) - MN3207 based EHX Electric Mistress (9V) clone
Post by: GodSaveMetal on June 13, 2014, 03:26:53 PM
THANKS MAN!!! GREAT!!!!!!!!!!!! :icon_mrgreen:
Title: Re: EM3207 (v1.1) - MN3207 based EHX Electric Mistress (9V) clone
Post by: lrgaraujo on February 16, 2015, 03:53:37 PM
Thanks a lot! That's a nice sounding one!
Title: Re: EM3207 (v1.1) - MN3207 based EHX Electric Mistress (9V) clone
Post by: Thomeeque on February 16, 2015, 05:27:08 PM
..and the pin 2 of the 1M pot is not connected in this layout, i see other schematic with this pin connected to the first pin

 Yeah, Build instructions, Build Note #7 ::)

 Hey guys, nice to see this thread still alive and kicking, cool stuff, thanks for pics and samples - still enjoying them (and special thanks to Dave for pointing people to the right places :icon_mrgreen:)

 Cheers, T.
Title: Re: EM3207 (v1.1) - MN3207 based EHX Electric Mistress (9V) clone
Post by: DrAlx on March 04, 2015, 11:51:47 AM
I've been looking through the earlier part of this thread, in particular the behaviour of the VCO when trying to achieve high clock rates. Thomeeque gave these measurements showing that for small CVs and delays, the linearity between CV and BBD delay is lost.  This can be seen as a flattening of the straight lines at the far left.  I think I can explain what causes this.

(http://thmq.mysteria.cz/em3207/build/EM3x07_clock_on_CC.gif) (http://thmq.mysteria.cz/em3207/build/EM3x07_clock_on_CC.gif)

I set the CV to a few volts, and used a scope to measure how the clock capacitor voltage changes while charging.  The graph of  capacitor voltage versus time sort of has two sections. A short section at the very start of the charge process where the cap is being charged at high rate, and a much longer section for the rest of the charge process where it is being charged at a slower rate. 
Low CV thresholds correspond to stopping the charge process in the first section where the charge rate is fast, and this gives the flattened CV to delay characteristic on the left of the above picture. Higher CV thresholds correspond to stopping the charge process in the second section where the charge rate is lower and governed purely by the transistor current source.  So what causes the high initial charge rate?

I believe the rapid initial charging is due to the reverse current through the discharge diode D2 as it switches itself off.  As D2 goes into reverse bias, it takes time for the diode to remove charge carriers and create the depletion region and the associated reverse current through D2 charges up the clock cap.  Simulation seems to back this up.  There are a few ways of mitigating the effect of this reverse diode current:

1) Increase the supply voltage. Scaling up voltages and currents everywhere makes the effect of diode reverse current less noticeable overall.  Decreasing the supply voltage makes the non-linearity more noticeable.

2) Increase the value of the pullup resistor R34 at the comparator output.  This makes the diode dump its charge onto the capacitor over a longer time period.  The  gradients of the two charge sections mentioned above then become more closely matched, but the "knee" between them moves to a higher voltage. Its just a guess, but maybe this explains why the original 9V EM uses a larger pullup resistor than the 15V Deluxe EM (10k rather than 3k3). Unfortunately, increasing R34 makes it harder to drive the 4013 quickly.

3) Use a bigger clock capacitor.  This makes the unwanted charge from D2 produces a smaller voltage increase on the cap.  This is evident in the graphs above.  The curves flatten out at lower CVs as the clock cap increases in value.  Note that changing the charge current using the trim pot RT3 only changes the gradient of the large linear portion of the graph.  There is little effect on the location of the "knee" i.e. the voltage at which the curve flattens out.

4) Keep the CV away from the non-linear region. In other words, work out the limitations of the VCO and design an LFO section to match it.
 

It's interesting that the type of measures taken to speed up the VCO cause the non-linearity to get worse. e.g. lowering the pullup resistor or using a smaller clock cap.

Although the EM3207 schematic shows a 22pF timing cap, Thomeeque later recommended 47pF on this thread and I would agree based on the above graphs and explanation.  It is better to use 47pF and higher charging current (by adjusting clock trimmer) than to use 22pF and lower charging current.  Funnily enough, the Madbean Current Lover and Hartmann Flanger (both clones of the 9V EM) use a 22pF timing cap rather than 47pF.  So you can probably just about get away with 22pF so long as the CV doesn't reach the non-linear bit of the charging curve.

So why not use an even bigger cap and charging current? I think there is a limit as to how big you can make them.  If you scale both up by a factor of 10, then the capacitor will have to discharge 10 times as much charge, and this becomes harder to do because the comparator realises the cap voltage has dropped and shuts off the diode before the capacitor can "fully" discharge.  (Note that the capacitor never fully discharges anyway because of the voltage drop across D2).


I see there is a design earlier in this thread for a faster VCO which claims to match the aim of doubling the Deluxe EM clock rate while keeping a linear characteristic. Has anyone (other than the designer) built and tested the VCO in the following link ... ?

http://www.diystompboxes.com/smfforum/index.php?topic=91981.msg803653#msg803653

It uses 22pF and a low value pull-up resistor.  So the nonlinearity in the CV to delay characteristic should be worse, but the CV appears to be kept deliberately high (1.6V to 6V) so I am thinking it stays away from the non-linear part of the characteristic. 
I'm asking 'cos I'm toying with the idea of a Deluxe EM clone using the 3207 but running on 9V instead of 15V.
 
Title: Re: EM3207 (v1.1) - MN3207 based EHX Electric Mistress (9V) clone
Post by: Thomeeque on April 03, 2015, 06:57:34 AM
 Hey Dr. Alx, that is impressive piece of serious R&D, thanks a lot for sharing! I did not continue on any deeper research on expanding clock range later. I was partly discouraged by gain loss in MN3207 at higher clocks and partly by the fact, that I have liked effect at default (limited) clock range, I am Gilmour type of the flanger user (setting it to get just subtle effect :)). Plus later I have installed my EM3207 prototype into friend's multi-fx unit and that was it. But recently I have bought one LM319 IC to at least try the Ralf's clock.. Did you get somewhere meanwhile?
Title: Re: EM3207 (v1.1) - MN3207 based EHX Electric Mistress (9V) clone
Post by: Thomeeque on April 03, 2015, 01:59:41 PM
.
Title: Re: EM3207 (v1.1) - MN3207 based EHX Electric Mistress (9V) clone
Post by: DrAlx on April 04, 2015, 07:22:11 AM
Hey Dr. Alx, that is impressive piece of serious R&D, thanks a lot for sharing! I did not continue on any deeper research on expanding clock range later. I was partly discouraged by gain loss in MN3207 at higher clocks and partly by the fact, that I have liked effect at default (limited) clock range, I am Gilmour type of the flanger user (setting it to get just subtle effect :)). Plus later I have installed my EM3207 prototype into friend's multi-fx unit and that was it. But recently I have bought one LM319 IC to at least try the Ralf's clock.. Did you get somewhere meanwhile?
Thanks Thomeeque.  I ordered a LM319 last week for the same reason.  That's as far as I've got.
Title: Re: EM3207 (v1.1) - MN3207 based EHX Electric Mistress (9V) clone
Post by: elflicho87 on February 05, 2016, 12:06:58 PM
Hi everybody,

First of all, a HUGE thanks to Tomas for sharing his great work here, and for giving support to other builders all over the forum.

I've just finished building my EM3207, and I'm glad to say that it works. I'll upload some pics later when calibration process is over (and when all the parts I ordered for the project arrive home grrrrr...)

Just one quick question for you diyers: I sadly do not own an oscilloscope, so I'd like to know if there are some advices about the clock trimmer calibration. I've managed to set the bias (with the formula and by ear) and the feedback (before oscillation starts) trimmers. Now on the clock trimmer: any suggestion? The pedal already sounds good but I'd like to get the best out of it, you know...

Thank you!
nic
Title: Re: EM3207 (v1.1) - MN3207 based EHX Electric Mistress (9V) clone
Post by: DrAlx on February 06, 2016, 05:03:21 PM
Hi everybody,

First of all, a HUGE thanks to Tomas for sharing his great work here, and for giving support to other builders all over the forum.

I've just finished building my EM3207, and I'm glad to say that it works. I'll upload some pics later when calibration process is over (and when all the parts I ordered for the project arrive home grrrrr...)

Just one quick question for you diyers: I sadly do not own an oscilloscope, so I'd like to know if there are some advices about the clock trimmer calibration. I've managed to set the bias (with the formula and by ear) and the feedback (before oscillation starts) trimmers. Now on the clock trimmer: any suggestion? The pedal already sounds good but I'd like to get the best out of it, you know...

Thank you!
nic
You don't need a scope. Just ears and an in-tune guitar.  Here is how I always do it. Use maximum color (regen) and maximum range in filter matrix mode. When clock trim is correctly calibtated that should give a delay of about 8ms. A delay of 8 ms corresponds to a frequency of 1000/8 = 125 Hz.  That is approximately the low B on the guitar's A string. So what you do is smack the strings over the pickups and listen to the metallic sound coming from the effect.  It should sound a bit like "twanging" a ruler on a desk. Adjusting the clock trimmer will change the pitch of that sound, and you try to make the pitch the same as the B (i.e. A string second fret).
Title: Re: EM3207 (v1.1) - MN3207 based EHX Electric Mistress (9V) clone
Post by: DrAlx on February 07, 2016, 02:56:59 PM
Here's what I was trying to describe above.

https://soundcloud.com/alex-lawrow/bbd-clock-trimming (https://soundcloud.com/alex-lawrow/bbd-clock-trimming)

Actually according the Electric Mistress Mystery page, the max range delay is more like 7 ms, which if 1000/7 = 142 Hz.
So the note would be between C# and D.  So instead of tuning to the "B" on the 2nd fret, tune a couple of frets further up.

Title: Re: EM3207 (v1.1) - MN3207 based EHX Electric Mistress (9V) clone
Post by: elflicho87 on February 08, 2016, 02:46:33 PM
Thank you very much Alex

I've just finished the process as you described it. Boxed it up and played a bit.
Sound good to me!

Again thanks to Tomas for all the work here and Alex for the reply and the link to the audio file!

cheers
nic
Title: Re: EM3207 (v1.1) - MN3207 based EHX Electric Mistress (9V) clone
Post by: PRR on February 09, 2016, 02:08:24 AM
I will not re-read all 20+ pages.

Are we looking at this fragment?

(http://oi67.tinypic.com/161nfw9.jpg)

I make it out as about 30uA of current in Q2, for an oscillator which goes over 1MHz.

That seems very thin to me.

Likewise, 22 even 47pFd sounds a lot like stray parasitic capacitance.

For Mhz operation I would dart-board mA of current. This gets C up near 500pFd-1000pFd, a good step up from the universal parasitics.

Actually getting 30X the current just means 30X reduction in R31 R32 R33 RT3. Hmmm, than makes RT3 733 ohms, an odd value. You show control voltage as high as 9V but also <4V. We could let the V across RT3 be maybe 2V or 4V (instead of 0.45V?) and get a more practical RT3 value. Details.

The next question is: can we re-set a mA of charge current fast enough? You would think a LM311 and a 1N4148 would dump current faster than a MHz. But I recall from synthesizer design that reset times can be disappointing. And LM311 has about 20 Ohms to-ground resistance for low output voltages. I recall using 2-transistor switches instead of a diode, to get really-swift reset.
Title: Re: EM3207 (v1.1) - MN3207 based EHX Electric Mistress (9V) clone
Post by: DrAlx on February 09, 2016, 07:11:58 AM
Yes it's that circuit fragment (and the 4013 that it then drives).

The circuit fragment (with 47pF clock cap) is from the original 9V Electric mistress (which used a 512 stage BBD).  This build takes that circuit but uses a 1024 stage BBD as a substitute.
So the requirement was to make the circuit fragment shown take the same control voltage range as the original pedal, but produce double the clock rate.  The original thinking was to use 22pF rather than 47pF but that stopped the CV -> Delay characteristic from being linear for small delays.  To cut a long story short, it turned out to be better to keep the original 47pF and just adjust RT3 to scale up the charging current by a factor of about 2. That achieved what was desired to get this 9V Electric Mitress clone working "to spec" against CV.  (Lowest delay when configured is not much less than 1ms.)


Now it so happens that the same circuit fragment is used in the 15V Deluxe Electric Mistress which has a wider range of CVs (due to larger supply) and that pedal can get much lower delays.  So if you want to clone a Deluxe EM but use a 1024 stage BBD instead of 512, the circuit fragment needs to run much quicker than was necessary for 9V build.  So the question was how quick could things be pushed while still making sure that the full range of delays were achievable with no loss of linearity in CV -> delay characteristic.  (Probably a pointless exercise due to BBD signal loss when overclocked but kind of interesting anyway).

The posts on the earlier part of the thread looked at a few things like trying quicker comparators, lower pull-up resistor on the comparator output to better drive the following 4013.
What I saw posted as a solution (which apparently worked but I never got round to doing a test build) used a quicker comparator and a shift in the range of CV voltages (to avoid the non-linearity that occurs at low CVs).  So I am guessing it could work but would involve messing around with the CV stage of the original DEM circuit too.

What you say about dumping charge more quickly using two transistor switches instead of a diode is interesting.  Any chance you could post a pic of what you mean Paul?
Title: Re: EM3207 (v1.1) - MN3207 based EHX Electric Mistress (9V) clone
Post by: Thomeeque on February 12, 2016, 04:48:49 AM
Again thanks to Tomas for all the work here..

 Always pleasure, congratulations to the successful build! :)

What you say about dumping charge more quickly using two transistor switches instead of a diode is interesting.  Any chance you could post a pic of what you mean Paul?

 Yes, please! :)

 Cheers, T.
Title: Re: EM3207 (v1.1) - MN3207 based EHX Electric Mistress (9V) clone
Post by: RickL on March 16, 2016, 03:32:04 PM
I've just finished building one of these and it works... for about 4 seconds. Then the delayed sound starts to distort and eventually fades away to nothing. If I short the battery terminals or remove the battery for a couple of seconds the delayed sound fades back in again for a few seconds, then fades out again. I'm getting signal into the input of the 3207 but nothing out of Out 1 or Out 2 when the signal fades.

I'm measuring about 9.4 V at Vdd (pin 5), about 8 V at Vgg (pin 4) and 0 V at ground (pin 1) of the 3207. These voltages stay constant. When I short the supply Out 1 and Out 2 slowly climb from 0 V to about 8 V then stay there. I'm getting clock signals at CP1 and CP2 that change speed with the Rate pot.

I've tried replacing the 3207 with the same results.

Suggestions? I get similar symptoms from an old EHX EchoFlanger and if I can fix this I may be able to fix the EchoFlanger.
Title: Re: EM3207 (v1.1) - MN3207 based EHX Electric Mistress (9V) clone
Post by: Scruffie on March 16, 2016, 04:40:37 PM
First off, similar issue doesn't mean the same problem, but i'm pretty familiar with the echoflanger circuit if you want some help with that.

Second, sounds like it's either the BBD bias or the output pulldown, check the resistor to ground from pins 7 & 8 of the 3207 is properly connected and check the v.ref electrolytic orientation and soldering.

Which exact schematic are you using?
Title: Re: EM3207 (v1.1) - MN3207 based EHX Electric Mistress (9V) clone
Post by: RickL on March 16, 2016, 05:37:17 PM
I'm using the schematic and layout here: http://thmq.mysteria.cz/em3207/build/EM3207_v1.1_Build_Instructions.pdf

R14 isn't connected directly from ground to pins 7 & 8, but I assume it is the pulldown resistor. I'll check it. The bias is Vgg isn't it (pin 4). I'm getting a solid 8 volts there that doesn't change as the voltage climbs on pins 7 & 8.
Title: Re: EM3207 (v1.1) - MN3207 based EHX Electric Mistress (9V) clone
Post by: Scruffie on March 16, 2016, 05:45:09 PM
No the bias is pin 3 of the BBD which is fed from IC1B and set through RT2, the electrolytic I referred to is C12.
Title: Re: EM3207 (v1.1) - MN3207 based EHX Electric Mistress (9V) clone
Post by: Lothric on June 25, 2016, 09:17:44 AM
Hello everyone, I know it might be stupid question, but I have some issues getting my hands on tantal caps. Can I use standard electrolytic caps instead? (missing 33uF, 1uf...) the closest values I have are  22uF 2,2uf tantals.
Title: Re: EM3207 (v1.1) - MN3207 based EHX Electric Mistress (9V) clone
Post by: DrAlx on June 29, 2016, 12:55:25 PM
Hello everyone, I know it might be stupid question, but I have some issues getting my hands on tantal caps. Can I use standard electrolytic caps instead? (missing 33uF, 1uf...) the closest values I have are  22uF 2,2uf tantals.
Electrolytics are fine.
Title: Re: EM3207 (v1.1) - MN3207 based EHX Electric Mistress (9V) clone
Post by: Lothric on September 26, 2016, 03:11:13 PM
Big Thanks to Thomas for this project. Finally I have build this thing! still have to debug few things tomorrow because I have a ticking noise from clock, will change c17 to 47pF and use filter caps on the IC's see how it goes... once again big thanks to everyone involved into this project
Title: Re: EM3207 (v1.1) - MN3207 based EHX Electric Mistress (9V) clone
Post by: Lothric on September 27, 2016, 03:25:19 PM
found problem, ground loop !!!, extra caps didnt help at all so at the end I didn't put them at all, used shielded wires on the input and output (grounded everything to the output jack which is connected to enclosure the input jack is isolated from the enclosure). very very nice flanger. Thanx again to everyone involved here specially Tomas  8)
Title: Re: EM3207 (v1.1) - MN3207 based EHX Electric Mistress (9V) clone
Post by: shoggoth2 on October 18, 2016, 08:07:33 PM
Just built one of these, it sounds fantastic.  I used a "bare box" style enclosure, which is very tight, so there's a daughterboard hidden underneath with most of the clock circuit on it.  I had the PCB's made up at Gold Phoenix (I did a big batch of different PCB's in a multipanel project, so overall a very good value compared to just getting a single board made up).

It's mostly the original schematic Thomeeque put together, plus some extra filtering here and there for reasons of paranoia, 47pf for the clock cap at C17, and the "sweep ratio" trimpot mod that DrAlx came up with.

Only problem I have is some popping on activation, I'm thinking it's a result of the "true bypass" 3pdt switch.  Pounding it on and off several times before turning the amp on helps.

Here's the guts:

(http://i234.photobucket.com/albums/ee257/LookingForCruiser/IMG_0782_zpsx4hn9znn.jpg)

Here's the enclosure - I screwed up the top waterslide decal, a combination of letting it sit in the water too long so it didn't have enough glue, and reassembling it so many times that I marred the surface pretty badly.  I'll do the next one better.

(http://i234.photobucket.com/albums/ee257/LookingForCruiser/IMG_0783_zpsphpelczs.jpg)
Title: Re: EM3207 (v1.1) - MN3207 based EHX Electric Mistress (9V) clone
Post by: D.C. on November 25, 2016, 05:13:44 PM
Only problem I have is some popping on activation, I'm thinking it's a result of the "true bypass" 3pdt switch.  Pounding it on and off several times before turning the amp on helps.

I've heard that that's often a function of the choice of output capacitor. Did you change any component values near the output?

I wonder if anyone else has had popping issues. 22 pages of posts is a lot to go through, though...
Title: Re: EM3207 (v1.1) - MN3207 based EHX Electric Mistress (9V) clone
Post by: DrAlx on November 28, 2016, 03:20:56 AM
Quote
Only problem I have is some popping on activation, I'm thinking it's a result of the "true bypass" 3pdt switch.

Have you wired the switch to turn the power to the board on and off? If so then change things so that the board is powered the whole time, and let the switch only handle the audio connections.
Title: Re: EM3207 (v1.1) - MN3207 based EHX Electric Mistress (9V) clone
Post by: DrAlx on February 20, 2017, 05:25:48 PM
I will not re-read all 20+ pages.

Are we looking at this fragment?

(http://oi67.tinypic.com/161nfw9.jpg)

I make it out as about 30uA of current in Q2, for an oscillator which goes over 1MHz.

That seems very thin to me.

Likewise, 22 even 47pFd sounds a lot like stray parasitic capacitance.

For Mhz operation I would dart-board mA of current. This gets C up near 500pFd-1000pFd, a good step up from the universal parasitics.

Actually getting 30X the current just means 30X reduction in R31 R32 R33 RT3. Hmmm, than makes RT3 733 ohms, an odd value. You show control voltage as high as 9V but also <4V. We could let the V across RT3 be maybe 2V or 4V (instead of 0.45V?) and get a more practical RT3 value. Details.

The next question is: can we re-set a mA of charge current fast enough? You would think a LM311 and a 1N4148 would dump current faster than a MHz. But I recall from synthesizer design that reset times can be disappointing. And LM311 has about 20 Ohms to-ground resistance for low output voltages. I recall using 2-transistor switches instead of a diode, to get really-swift reset.

So one year later I finally come back to this.  Paul's right as usual  ;)  I tried the following set of component changes

62k ==> 3k3
1M2 ==> 22k
3k9 ==> 2k7 (and no clock trimmer)
47p ==> 470p
10k pull-up resistor on the comparator ==> 1k

This was just plugging things into breadboard with messy wires everywhere.

The CV range that managed to trigger the CD4013 OK was from 0.995V to 6.94V.
This gave really good CV to delay characteristic (as far as my handheld scope could measure) with corresponding delay times from 0.32 ms to 9.73 ms.  Graph here...

https://1drv.ms/x/s!AvrH61utWEtEhSZ-54HeAD0DV-PZ (https://1drv.ms/x/s!AvrH61utWEtEhSZ-54HeAD0DV-PZ)

And when I looked at the capacitor waveform as it charged it was properly triangular.  The initial fast charging due to diode reverse current wasn't evident as it was with 47pF clock cap.

Title: Re: EM3207 (v1.1) - MN3207 based EHX Electric Mistress (9V) clone
Post by: DrAlx on March 08, 2017, 03:38:07 PM
I've built an original 18V EM with SAD1024 using the schematic on the Electric Mistress Mystery page.  Even allowing for the volume drop, there is a noticeable difference in sound compared to the EM3207.  I know the EM3207 is a clone of the 9V EM and that there are differences in the audio path compared to the 18V EM.  I like the sound of the EM3207 but I prefer the sound of 18V EM so I wanted to see if I could modify the EM3207 to achieve that sound.  I think I now understand why the original EM sounds like it does, and will describe how the EM3207 can be modified to make it sound much closer to both the original 9V and 18V versions.

Here is how the relevant section of the EM3207 compares to the 18V version.  I've highlighted the key differences in component values.

(http://i1368.photobucket.com/albums/ag185/DrAlx/EM3207_1_zps6lo0pvfi.png) (http://i1368.photobucket.com/albums/ag185/DrAlx/EM3207_1_zps6lo0pvfi.png)

(http://i1368.photobucket.com/albums/ag185/DrAlx/EM3207_2_zpsvkrdwbgu.png) (http://i1368.photobucket.com/albums/ag185/DrAlx/EM3207_2_zpsvkrdwbgu.png)

The 18V EM uses smaller cap values for C8 and C10 and this reduces frequency content in the lower midrange (a couple of hundred Hz).  That's higher than the frequency of the low open strings on the guitar, and those strings are indeed quieter than the high strings on the 18V version. 

So I changed C8 and C10 to 47 nF.  The side effect of reducing the low-mids like this is that there is a noticeable volume drop overall.  This reduction of low mids is one of the main contributions to the volume drop in the 18V EM.  So the next thing I did was increase R9 in the pre-emphasis section from 5k6 to 6k8 (as in the 18V EM).  This increases the overall gain and recovers most of the volume drop lost to reduced low-mids.  Increasing R9 didn't give me any problems with headroom or clipping.

In the end, I ended up changing all cap and resistor values in the audio path to match the 18V EM values (i.e. all the values in red on the above diagram apart from R14 and C7 on the BBD output).  These changes made the EM3207 sound more like the 18V EM but I could tell that something still did not sound the same.   This was when I decided to take measurements given that I had already made the necessary component value changes to make the two circuits "match".  I only have a handheld scope that is not lab quality but it is still better than making subjective comparisons based on my ears.

I started by measuring what I'll call "BBD gain" for the two circuits.  To be more precise, for each circuit I measured 20log10(Vout/Vin) where Vin is the pk-pk voltage measured at the BBD input, and Vout is the pk-pk voltage measured at the smoothing cap C7.  I took measurements in filter matrix mode with no feedback, using 7 different clock rates covering the whole sweep range (using doubled clock rates for EM3207 of course), and using 21 audio frequencies from 100 Hz to 11 kHz.  The following graph shows the measured BBD gain.

(http://i1368.photobucket.com/albums/ag185/DrAlx/Graph1_zpsvzhjbxmg.png) (http://i1368.photobucket.com/albums/ag185/DrAlx/Graph1_zpsvzhjbxmg.png)

The EM3207 shows a mainly flat BBD gain of roughly 2 dB, in agreement with the MN3207 datasheet.
The 18V EM shows a significant roll-off in BBD gain in the audio band.

If we subtract one curve from the other ("18V EM BBD Gain" minus "EM3207 BBD Gain") we get the following curve that gives the relative BBD gain between the two circuits.  The point of doing this is to use the EM3207 BBD gain as a baseline for comparison, effectively subtracting out any drop in BBD gain that is common to both circuits.

(http://i1368.photobucket.com/albums/ag185/DrAlx/Graph2_zpsnqorruug.png) (http://i1368.photobucket.com/albums/ag185/DrAlx/Graph2_zpsnqorruug.png)

This last graph shows that the BBD gain in the 18V EM has suffered a sort of "shelving" effect. In other words, there is a roll-off in gain that flattens out at low and high audio frequencies.  The reason for this is that the 18V EM does not just have a 10k resistor on its BBD output.  It has the rest of the mixing circuit hanging off it too.  This means that for high audio frequencies there is not 10k on the BBD output but a much lower impedance instead.  Lower impedance on the BBD output means lower BBD gain.
 
In the EM3207 circuit, Q1 shields the BBD output from the rest of the mixing circuit and so prevents the roll-off in BBD gain.  This makes the EM3207 a more "pure" flanger but on the other hand it stops it emulating a key part of the original circuit's tone.  (Note that the original 9V EM by EHX will also have a roll-off in BBD gain but it will be "shelved" differently to the 18V EM because it has "trim resistors" in series with the drain-source resistance of the BBD output.)

I believe Thomeeque included Q1 because the outputs of the MN3207 have much higher drain-source impedance than the SAD1024.  Something like 4k5 compared to 1k for the SAD1024.  So the MN3207 chip needs 47k for R14 in order to give similar gain to the SAD1024 with 10k.  Including Q1 allows all the other caps and resistors in the mixing/feedback circuitry to use the values of the original EM circuit.  The other option would have been to leave out Q1 entirely and instead rework the mixing/feedback circuitry by scaling up resistor values by a factor of 4.7 and scaling down cap values by the same factor (just as Thomeeque did for the components on the BBD output). I am not sure why that approach was not taken.  I could be missing something ???   The overall output impedance would go up by doing that, but that could be corrected with an output buffer.

Anyway I was too lazy to change out any more components, and wanted to see if there was a simple modification that would give the EM3207 a roll-off in BBD gain matching that of the 18V EM.  I worked out I could get a good approximation to the shelving effect by putting (15k + 6n8) across the 47k resistor at the BBD output of the EM3207 as follows.

(http://i1368.photobucket.com/albums/ag185/DrAlx/EM3207_3_zpslu4hyg0x.png) (http://i1368.photobucket.com/albums/ag185/DrAlx/EM3207_3_zpslu4hyg0x.png)

Note: A similar sort of trick could be used to mimic the BBD gain roll-off seen in the original 9V EM, although I didn't calculate the values needed for that as I don't have a working reference circuit of the 9V EM from which to take measurements.

I took another set of measurements after my "shelving" modification, and the following graph shows what happened to the relative BBD gain.

(http://i1368.photobucket.com/albums/ag185/DrAlx/Graph3_zps2af34mam.png) (http://i1368.photobucket.com/albums/ag185/DrAlx/Graph3_zps2af34mam.png)

The relative BBD gain between the two circuits is now pretty flat across the audio bandwidth and varies by less than +/-0.2 dB. Overall the EM3207 still has a BBD gain that is about 0.5 dB higher than the 18V EM.  That could be fixed in several ways (e.g. by reworking the R and C values of the things hanging off the BBD output pins) but I didn't want to change any more values and think I will live with the 0.5 dB difference in BBD gain in my build.
 
Summary of overall result with the above modifications ...

1) The circuit now sounds much more like an original 18V EM.  Maybe I'm cork-sniffing but I think the difference is significant.  You would think that throwing away high frequencies in the wet path would make things sound less clear but I found the opposite to be true.  My EM3207 now has the same sort of watery clarity as the original 18V EM. That could be related to point 3 below though.

2) The EM3207 ends up with a small volume drop. It is not as bad as the original 18V EM though because of the boost at the input.

3) Noise is noticeably lower after the mods :)  Connecting/disconnecting the "shelving" mod at the BBD output makes this obvious.  Maybe that explains the improvement in clarity.  For the same overall volume, there's less noise present, especially in the high frequencies because those get to the output more through the less noisy "dry" path than through the noisy "wet" one.  I'd say the noise reduction alone makes the shelving mod worthwhile.

3) Feedback/Color pot is less harsh after the "shelving" mod.


What I've learnt from all of this is that the original EM (probably my favorite pedal) sounds the way it does mainly because of all the signal that it throws away.  It reduces low-mids during mixing, and it reduces highs in the wet path due to the "shelving" in BBD gain.  (The sweep giving linearly increasing delay is also important).

Based on what I've learnt above, my plan is to do a clone of the 18V EM but using MN3207 chip running at 9V.   My aim is to make it a  "sound-alike" and "control-alike" rather a straight copy of the circuit.  So basically I am going to rip out the LFO/VCO used in the 18V EM (which is horribly noisy) and replace it with something along the lines of the LFO/VCO of the 9V EM but with better VCO values and different filter matrix switching and range pot behaviour.
I think I can reduce the part count a bit too.
One other thing that I will do is redo the BBD gain measurements for the EM3207 but without the clock buffers.  I know the circuit will work without the buffers but getting a quantitative measurement of how much they affect the BBD gain (if at all) will be useful.
Title: Re: EM3207 (v1.1) - MN3207 based EHX Electric Mistress (9V) clone
Post by: Cozybuilder on March 08, 2017, 11:42:26 PM
Alex- Very impressive amount of work you've done on this, great write-up, can't wait to try it out.
Title: Re: EM3207 (v1.1) - MN3207 based EHX Electric Mistress (9V) clone
Post by: 12Bass on March 08, 2017, 11:49:39 PM
Nice work, DrAlx!

It seems that a large part of what makes the EM unique is the coloration to the wet path.  Some audio samples would be great. 

With my SAD1024 A/DA build I took things in another direction - increasing the bandwidth of the delay path - which makes it more "hi-fi" sounding, especially when flanging high frequency content.  This increased noise somewhat, but I prefer the overall tone.  I also altered the gain staging slightly to try to maximize the SNR through the wet path.  Raising the HPF on the feedback path also helps to clean things up as regeneration increases.
Title: Re: EM3207 (v1.1) - MN3207 based EHX Electric Mistress (9V) clone
Post by: DrAlx on March 09, 2017, 05:20:18 PM
I got back from work today and had another listen.  The change in tone is all from the C8 and  C10 change which makes sense since that affects the midrange.
The shelving mod doesn't change the tone but does make it less noisy and hence clearer. 
(I was listening with headphones so could here the change easily).
I was playing one handed and making/breaking a connection to the shelving mod with the other hand I could hear some of the hiss disappearing.  The actual guitar sounded the same though. I was just playing clean. No distortion.
The other effect from the shelving mod is to do with how it affects color/feedback. You can feedback more before the thing oscillates.
Title: Re: EM3207 (v1.1) - MN3207 based EHX Electric Mistress (9V) clone
Post by: DrAlx on March 30, 2017, 07:37:34 PM
While taking measurements to investigate the effect of clock buffers (something I'll post on another thread) I found I was
getting a different shelving effect on my original 18V EM compared to the measurements I had taken before.
I figured out that I had changed the setting of the feedback trimpot RT1 on the original EM and this had altered things.
So the hack I mention above (of adding 6n8 + 15k) only approximates one particular setting of RT1.
I had a think about dropping Q1 and scaling resistor and cap values instead, but decided against it to avoid degrading noise performance.

I now think a better way to clone the shelving behaviour of the original circuit is to give the smoothing cap C7 a value of 3n3 as in the original 18V EM, but move the cap to the other side of Q1 and separate it from Q1 with a resistor.  The value of this resistor should be chosen to equal 10k in parallel with the drain-source impedance of a BBD output on a SAD1024.   i.e. the impedance seen by the C7 to the left should be the same as in the original circuit.

(http://i1368.photobucket.com/albums/ag185/DrAlx/EM3207_4_zpsmlhsunrl.png) (http://i1368.photobucket.com/albums/ag185/DrAlx/EM3207_4_zpsmlhsunrl.png)

This makes the shelving effect the same as the original 18V EM for all settings of RT1.
The other advantage of this approach is that the BBD gain can be independently trimmed to match an SAD1024 by tweaking R14, and no other cap or resistor values would need to be changed.
Title: Re: EM3207 (v1.1) - MN3207 based EHX Electric Mistress (9V) clone
Post by: G.esp on August 15, 2017, 06:04:38 AM
I'm planning to build this one. I read that there are some fixes to improve sound, someone has a new schematic with all these fixes?
Title: Re: EM3207 (v1.1) - MN3207 based EHX Electric Mistress (9V) clone
Post by: DrAlx on August 16, 2017, 08:00:26 AM
Shared here.
https://1drv.ms/i/s!AvrH61utWEtEiAbzPDPv5UK-geVK
The "Rds || 10k" comes to a value of about 1.1k to 1.2k based on my measurements on an actual SAD1024.



Title: Re: EM3207 (v1.1) - MN3207 based EHX Electric Mistress (9V) clone
Post by: daz061 on August 28, 2017, 05:37:39 AM
so does anybody sell a prefabbed board for this project
Title: Re: EM3207 (v1.1) - MN3207 based EHX Electric Mistress (9V) clone
Post by: AS74 on December 11, 2017, 06:40:37 AM
Has anybody made the effect with DrAlx last changes?  Opinions will be appreciated as I am currently populating the pcb.

Thank you.
Title: Re: EM3207 (v1.1) - MN3207 based EHX Electric Mistress (9V) clone
Post by: NFX on December 11, 2017, 08:48:35 AM
I would also like to know, so have you etched your own board or had 1 made for you AS74?
Title: Re: EM3207 (v1.1) - MN3207 based EHX Electric Mistress (9V) clone
Post by: AS74 on December 11, 2017, 07:21:13 PM
Etched my own board.

Thanks to Tomas.
Title: Re: EM3207 (v1.1) - MN3207 based EHX Electric Mistress (9V) clone
Post by: Tompski on November 08, 2018, 09:47:25 AM
Hello
Sorry to ressurect an old thread,

I have a version of this that uses the Madbean Current Lover circuit using MN3007, I have an original V2 Electric Mistress, and the modern pedal seems to be much thinner and occupy a higher frequency range in the top end, before I start swapping out capacitors has anyone got a list of possible mods that make the pedal sound more like an original V2? I think the originals sound warmer, thicker and more organic.

I can follow instructions and have good tidy soldering skills but a lot of the technical talk on here goes over my head.

Any help in getting this circuit to sound more like an original would be greatly appreciated.

thanks

Tompski
Title: Re: EM3207 (v1.1) - MN3207 based EHX Electric Mistress (9V) clone
Post by: Govmnt_Lacky on November 08, 2018, 11:50:24 AM
Hello
Sorry to ressurect an old thread,

I have a version of this that uses the Madbean Current Lover circuit using MN3007, I have an original V2 Electric Mistress, and the modern pedal seems to be much thinner and occupy a higher frequency range in the top end, before I start swapping out capacitors has anyone got a list of possible mods that make the pedal sound more like an original V2? I think the originals sound warmer, thicker and more organic.

I can follow instructions and have good tidy soldering skills but a lot of the technical talk on here goes over my head.

Any help in getting this circuit to sound more like an original would be greatly appreciated.

thanks

Tompski

The only mod you could do to make them sound identical (both sound like the V2) would be to rebuild the Current Lover to use the SAD1024 chip  :o

Sorry to say but, you will never get the same sound from it with an MN-series BBD as you would with a Reticon SAD-series.
Title: Re: EM3207 (v1.1) - MN3207 based EHX Electric Mistress (9V) clone
Post by: Tompski on November 08, 2018, 12:12:59 PM
Why?

Howard Davis who designed the Deluxe EM said the warmth and fullness of that pedal was just as much to do with the circuit as the SAD1024.
Title: Re: EM3207 (v1.1) - MN3207 based EHX Electric Mistress (9V) clone
Post by: 12Bass on November 08, 2018, 02:29:26 PM
The only mod you could do to make them sound identical (both sound like the V2) would be to rebuild the Current Lover to use the SAD1024 chip  :o

Sorry to say but, you will never get the same sound from it with an MN-series BBD as you would with a Reticon SAD-series.
I'm also curious to know why that would be. 

From what I gather, the SAD1024 has better high frequency response than the MN3007, so I'd expect it to be a little brighter rather than warmer, assuming the before and after filtering stayed the same.  There could be a bit of improvement in fidelity if the Reticon BBD were used in parallel-multiplex, but I'm not sure if that's used in the original Mistress. 
Title: Re: EM3207 (v1.1) - MN3207 based EHX Electric Mistress (9V) clone
Post by: ElectricDruid on November 08, 2018, 05:09:25 PM
The only mod you could do to make them sound identical (both sound like the V2) would be to rebuild the Current Lover to use the SAD1024 chip  :o

Sorry to say but, you will never get the same sound from it with an MN-series BBD as you would with a Reticon SAD-series.

Evidence? Otherwise it's just somebody's opinion I read on an internetz forum somewhere ;)

There *are* significant difference between the two chips, one of the most notable being the clock input capacitance, which is 7pF on the SAD1024 and 700pF on the MN3207. That means you can get some shorter delays from the SAD1024.
Is that what you're claiming here? That the sweep range on the original gets to the short end that the MN3207 can't reach?

Some numbers on it would be nice to enable us to tie this to facts. Enlighten me.

Title: Re: EM3207 (v1.1) - MN3207 based EHX Electric Mistress (9V) clone
Post by: Tompski on November 08, 2018, 06:09:36 PM
I asked someone who knows a thing or two about pedals and circuits to compare the Current Lover ( I am using a MN3007 not MN3207) to the circuit diagram of a V2 original and this was his reply

 - One thing that jumps out is that it looks like the Current lover has a make up gain stage at the end after the mixer (IC7_A) which provides the provision for the volume control. The EHX V2 not only just has a passive mixer output with no make up gain but it also has a low pass filter (470ohm / 47n) right at the output. So that would make it substantially warmer sounding than the Roxanne. Plus, the V2 would have a higher output impedance loading the amp or next pedal which would also contribute to a warmer tone.

If you want to keep to make-up gain stage at the end I would suggest tuning it to have a warmer output. You could also of course eliminate that final make up gain and have it output passively like the V2.

http://www.metzgerralf.de/elekt/stomp/mistress/images/1976-electric-mistress-v2-schematic.gif

http://www.madbeanpedals.com/projects/_folders/FilterMod/pdf/CurrentLover_2015.pdf?fbclid=IwAR1XVWp8KIj4cwfWdlziBsNNJ9EQ01n7hyNQM9n3VFTzuxC3V1R4QNMrSxk
Title: Re: EM3207 (v1.1) - MN3207 based EHX Electric Mistress (9V) clone
Post by: Scruffie on November 08, 2018, 06:56:12 PM
The V2 lacks the input filter of the 9V the current lover is built on (the 1nF cap parallel to the 5k6, although this removes a lot of the aliasing noise in the V2 but it can be reduced to brighten things up a bit) the output filter is different to the 9V (470R vs 510R Edit: Seems the Current Lover used the V2 470R not the 9V 510R) it has a different delay range (20KHz minimum instead of 35KHz, which is 40 vs 70 for the MN3007 which will alter the sound a lot) and a different sweep shape (the LM311 VCO adds a 'lag' to the sweep).

That may not sound like much but it changes the sound quite a lot.

The MN3007 over SAD1024 shouldn't be a huge factor, while true it inherently rolls off a bit more highs than a SAD1024 it's not a night and day difference and you'd be hard pressed to notice it in a mistress, it will have less noise (although sometimes a little noise can be a good thing, I think reduction in noise is part of the reason some say the panasonic chips can sound "sterile") than either electric mistress due to running at twice the clock frequency (plus improved S/N) as the SAD1024 in the mistress doesn't make use of parallel multiplexing and the gain is fairly linear at the clock frequencies the mistress runs which is usually the issue when switching from SAD1024 to MN3007 as the MN3007 drops off gain at higher clock frequencies resulting in a less than 50/50 mix which reduces depth of flanging.

There's also running the pedal on 9V as opposed to the 12-13.5V the V2 provides and yes, the output boost has an effect on things too (although it's certainly useful on the mistress) but I suspect your biggest problem might be the clock frequency, a different delay range gives a very different sound.

Edit: That 220n/10k pair on the output boost input is cutting some bass, might be worth increasing the value of the cap to 1uF.
Title: Re: EM3207 (v1.1) - MN3207 based EHX Electric Mistress (9V) clone
Post by: Govmnt_Lacky on November 09, 2018, 05:25:57 PM
Evidence? Otherwise it's just somebody's opinion I read on an internetz forum somewhere ;)

There *are* significant difference between the two chips, one of the most notable being the clock input capacitance, which is 7pF on the SAD1024 and 700pF on the MN3207. That means you can get some shorter delays from the SAD1024.
Is that what you're claiming here? That the sweep range on the original gets to the short end that the MN3207 can't reach?

Some numbers on it would be nice to enable us to tie this to facts. Enlighten me.

Much of it is my opinion based on multiple builds with either chip however, what Scruffie says pretty much covers it. Most importantly (to me) being the flange depth difference.
Title: Re: EM3207 (v1.1) - MN3207 based EHX Electric Mistress (9V) clone
Post by: ElectricDruid on November 09, 2018, 06:59:55 PM
Thanks both. That was indeed enlightening.
Title: Re: EM3207 (v1.1) - MN3207 based EHX Electric Mistress (9V) clone
Post by: Tompski on November 09, 2018, 07:06:36 PM
What about my friend’s suggestion in my quote?
Title: Re: EM3207 (v1.1) - MN3207 based EHX Electric Mistress (9V) clone
Post by: Scruffie on November 09, 2018, 07:25:47 PM
What about my friend’s suggestion in my quote?
Try my suggestion about the output boost cap first (you could also increase the resistor but you'll need a larger volume trimmer) that bass cut could be your problem.

High output impedance isn't exactly desirable and unless the mistress is last in the chain or has nothing buffered after it, it wont always have the desired effect.
Title: Re: EM3207 (v1.1) - MN3207 based EHX Electric Mistress (9V) clone
Post by: 12Bass on November 11, 2018, 06:31:29 AM
... the SAD1024 in the mistress doesn't make use of parallel multiplexing and the gain is fairly linear at the clock frequencies the mistress runs which is usually the issue when switching from SAD1024 to MN3007 as the MN3007 drops off gain at higher clock frequencies resulting in a less than 50/50 mix which reduces depth of flanging.

That makes sense.  In my A/DA build I added a trimpot at the output of the SAD1024 in order to tweak the mix; it's set so that the deepest comb filtering occurs in the mid/high part of the sweep where the effect is most dramatic (measured with a spectrum analyzer).  BTW, I've found that the SAD1024's gain also drops off at high clock frequencies, and varies somewhat throughout the range, though perhaps not as much at the Panasonic BBDs (haven't made a comparison).
Title: Re: EM3207 (v1.1) - MN3207 based EHX Electric Mistress (9V) clone
Post by: Scruffie on November 11, 2018, 09:24:58 AM
... the SAD1024 in the mistress doesn't make use of parallel multiplexing and the gain is fairly linear at the clock frequencies the mistress runs which is usually the issue when switching from SAD1024 to MN3007 as the MN3007 drops off gain at higher clock frequencies resulting in a less than 50/50 mix which reduces depth of flanging.
BTW, I've found that the SAD1024's gain also drops off at high clock frequencies, and varies somewhat throughout the range, though perhaps not as much at the Panasonic BBDs (haven't made a comparison).
That's interesting, I'm trusting the datasheets to be accurate here (and the Panasonic ones have been in my experience and even a little conservative in some areas) the SAD1024 claims linear response up to nearly 1MHz but I already knew it overstated its abilities a little bit with its claim of a 340mS max delay time... I'm sure it sounds wonderful with 750Hz filtering.
Title: Re: EM3207 (v1.1) - MN3207 based EHX Electric Mistress (9V) clone
Post by: 12Bass on November 11, 2018, 10:18:34 AM
That's interesting, I'm trusting the datasheets to be accurate here (and the Panasonic ones have been in my experience and even a little conservative in some areas) the SAD1024 claims linear response up to nearly 1MHz but I already knew it overstated its abilities a little bit with its claim of a 340mS max delay time... I'm sure it sounds wonderful with 750Hz filtering.

LOL

IIRC, I measured a 2dB loss at 1MHz along with a slight gain (and noise) increase at the longest delay times (with A/DA clone).  It may well be more linear than the Panasonic chips.  Gain aside, IMO, the SAD1024 has excellent audio fidelity at high clock rates in parallel-multiplex... the delay path is super clear sounding! 
Title: Re: EM3207 (v1.1) - MN3207 based EHX Electric Mistress (9V) clone
Post by: JC103 on December 26, 2018, 12:24:31 PM
A few quick notes from my experiences in 2018:

I have 2 older MB Current Lovers running with MN3007 chips, both biased for 12V operation. I have an even older Ross Flanger with the 18V Mistress BBD. I have played the new and "improved" MB Current Lover designed only for the MN3007. You can hear the 18V Mistress tone in the Ross, I believe it is the chip's high frequency character that defines the sound that we love from the V2 era Mistress. The newer version of the CL does not sound very good to me. I think the opamp makeup gain on the output is part of the problem. I prefer the older CL version with the transistor make up gain. Thinking out loud... both MN3007 versions of the CL only use a single BBD, where as the V2 Mistress uses both halves of its BBD. I have experimented using my CL's in stereo as well as summing to mono. I think it sounds better/more authentic with two BBD lines, but the high frequency response is still not quite right when compared to vintage units. Would love to figure out a work around in the future considering that the Reticons are unobtanium.
Title: Re: EM3207 (v1.1) - MN3207 based EHX Electric Mistress (9V) clone
Post by: pelut5 on November 30, 2019, 07:32:56 AM
Here's what I was trying to describe above.

https://soundcloud.com/alex-lawrow/bbd-clock-trimming (https://soundcloud.com/alex-lawrow/bbd-clock-trimming)

Actually according the Electric Mistress Mystery page, the max range delay is more like 7 ms, which if 1000/7 = 142 Hz.
So the note would be between C# and D.  So instead of tuning to the "B" on the 2nd fret, tune a couple of frets further up.

Thanks a lot.
I've adjusted the internal trimmers (as you explain) of my DEM V2 and now it sounds perfect !!!
Best regards.
Title: Re: EM3207 (v1.1) - MN3207 based EHX Electric Mistress (9V) clone
Post by: DrAlx on January 21, 2020, 07:46:33 PM
A few years ago I made a lengthy post (page 22 of this thread) looking at how the frequency response of the wet path (i.e. BBD onwards) in the EM3207 compared to an original EM using an SAD1024.

I found that the frequency response in the "wet path" of an original EM drops off more strongly than in the EM3207.
This can explained by the presence of the transistor buffer Q1 at the BBD output in the EM3207, and the lack of such a buffer in the original EM.

I believe Thomeeque put in Q1 because the EM3207 has (47k || 680nF) on its BBD output rather than (10k || 3nF) as in the original EM.  The buffering effect of Q1 causes more highs to feed into the path that follows (i.e. C8 onwards).
That is not what happens in the original EM.  The highs in the original EM wet path get shelved off (i.e. lowered with increasing audio frequency).

I suggested some mods for the EM3207 to make the circuits a closer match (e.g. by adding extra components before/after Q1) but I have now found what I think is a far simpler and better way of doing this.

I asked myself why Thomeeque used the values he did on the output of the BBD in the first place, instead of using 10k like the original EM ?  There is nothing in the MN3207 datasheet saying that a resistor of about 47k is necessary.  The example circuit in the datasheet shows (100k || 100k) on the BBD outputs, so maybe 47k was chosen based purely on that circuit?

Anyway, I got out my old EM3207 build to try something and guess what?
You can change the parts on the BBD output to match the original EM and drop the Q1 buffer completely!!!
The maximum BBD gain of the EM3207 is then slightly reduced by doing this (about 1dB), and this is actually a good thing if you want a closer match to the SAD1024.
Note that maximum gain of the MN3207 is slightly over 2dB (according to datasheet and my measurements on the pre-modded EM3207), while SAD1024 with 10k BBD output resistor has gain of about 1dB.

So to summarise. If you make the changes mentioned here, you'll have a closer match to the SAD1024 based circuit, and lower noise than the original EM3207 too (since the shelving effect in the wet path once Q1 is removed reduces hiss).
Title: Re: EM3207 (v1.1) - MN3207 based EHX Electric Mistress (9V) clone
Post by: DrAlx on January 22, 2020, 07:36:07 AM
Correction:  I just compared the result of the above mods and Q1 removal against an SAD1024 based EM, and my EM3207 now sounds too thin and trebly by comparison.
I can't tell if I messed up while modding things (its built on vero with solder all over the place) or if I have overlooked something.
So I don't recommend making the mod until I've got to the bottom of that.
Title: Re: EM3207 (v1.1) - MN3207 based EHX Electric Mistress (9V) clone
Post by: Scruffie on January 26, 2020, 09:12:50 AM
Impedance.
Title: Re: EM3207 (v1.1) - MN3207 based EHX Electric Mistress (9V) clone
Post by: DrAlx on January 26, 2020, 09:48:15 PM
The problem was with my "original" EM build. I had added an extra cap on the input that was dulling the sound. 

I am in the process of taking lots of measurements of 3207 against an SAD1024 clocked at half the rate and looking at BBD gain dependence on BBD output load impedance.

If all you have is 10k || 3n3 on the BBD output (and no other parts) then I found I was getting identical BBD gain for both chips across the whole audio band for practically the full clock range.  Only when 3207 was at 400kHz (using 4050 clock buffer) was I getting slight gain loss of 0.8 dB at highest audio frequencies, and the audio below 1600Hz still had same gain on both chips.

Biggest difference between the 2 chips when used in the EM circuit is that the 3207 does not have as high gain as the SAD1024 once you lower the load on the BBD output. e.g. using 3k3 || 3n3 on BBD outputs makes the 3207 between 2.3dB and 2.8dB weaker than the SAD1024.

If you look at the full network hanging off the BBD output in the original EM you see the impedance drop from 10k at DC to around 2k at 10kHz.  That impacts the 3207 more than the SAD1024.  I think the drain-source impedance of the BBD output is about 1k for the SAD1024 and and 3k3 for the 3207.

So the changes I mention above (strip Q1 and use same network as original EM) will have the effect of losing too many highs in the BBD path (3 dB more than an original EM by the time you get to 10kHz), while not making the changes will do the opposite and the BBD gain will be about 3dB larger then an original EM circuit for the high frequencies.



Title: Re: EM3207 (v1.1) - MN3207 based EHX Electric Mistress (9V) clone
Post by: rankot on January 27, 2020, 02:46:14 AM
Is this the schematic you're talking about?

(https://i.postimg.cc/vxzbJ2kV/EM3207-v1-1-schematic-1280.gif) (https://postimg.cc/vxzbJ2kV)
Title: Re: EM3207 (v1.1) - MN3207 based EHX Electric Mistress (9V) clone
Post by: DrAlx on January 27, 2020, 03:12:39 AM
Yes, but with some R and C changes made to the audio path so that it matches this ...
http://www.metzgerralf.de/elekt/stomp/mistress/images/1976-electric-mistress-v2-schematic.gif.
Title: Re: EM3207 (v1.1) - MN3207 based EHX Electric Mistress (9V) clone
Post by: DrAlx on January 27, 2020, 07:05:48 PM
 Removed post. Posted before completed typing....
Title: Re: EM3207 (v1.1) - MN3207 based EHX Electric Mistress (9V) clone
Post by: DrAlx on January 27, 2020, 08:04:14 PM
OK I have now done a thorough test of the BL3207 vs SAD1024 in the V2 Electric Mistress Circuit.
Based on my measurements, my suggestion to drop Q1 and just use the default V2 circuit values works really well.
I measured less than 1dB difference between the two chips across almost all audio frequencies and clock frequencies in the range of interest.  There is one difference though that I will mention right at the end.

I made the following test setup to rule out any differences down to part tolerances.

1) I used a CD4047 chip to generate a reference clock.
    I tested with 4 clock frequencies that span most of the range used by the BL3207:  50 kHz, 100 kHz, 200kHz, 400 kHz.

2) The CD4047 drives a CD4050B clock buffer for the BL3207.  The 4050 gives a bit more gain than the CD4049B or CD4049UBE chips at high clock frequencies (I did tests for this before).

3) The buffered clock from the CD4050B also clocks a CD4013. The CD4013 therefore provides a clock for the SAD1024 that is exactly half the clock rate of the BL3207.

4) Both BBDs have their bias set independently and optimised for the highest clock frequency.
SAD1024 and its clock (CD4013) were powered from a 12V supply.
BL3207 and all other chips in the test were powered from a 9V supply.

5) Each BBD has its 2 outputs tied together, so there is effectively a single output test point on each BBD.

6) The test audio signal is a sine wave and the same signal goes to both BBD inputs.  I tried audio frequencies from 100 Hz to 20kHz.

7) I made a single test load based on the parts on the BBD output in the V2 EM.
I assumed the color trimmer has a fixed value of 3k9 and that the color pot was turned to minimum.
So the test load is this:

 10k || 3n3 || (47n + (3k9 + 10k || [470 + 47n]) ||  (10k + [470 + 47n] || [13k + 47n]))

I built this as a standalone network.  For any given audio signal and clock frequency I just attach that load between ground and the BBD output I want to measure, and read the pk-pk voltage at the BBD output.  It's quick and easy to switch the load from one BBD to the other and get comparison of voltages.

I was shocked at how good the agreement was.  Following table shows BL3207 BBD gain relative to SAD1024 gain (dB) for the 4 test clock rates.  Negative values mean SAD1024 was stronger output.

Values are typically less than 1 dB different, showing that best way to get EM3207 to match original EM is to leave out Q1 completely and just use the same component values as the original EM.

Audio (Hz)   50kHz   100kHz   200kHz   400kHz
100   0.35   0.35   0.00   0.00
200   0.35   0.35   0.35   0.00
400   0.00   0.00   0.00   0.37
800   -0.41   0.00   0.00   0.00
1000   0.00   0.00   0.00   -0.45
2000   -0.51   -0.26   -0.26   0.00
4000   -0.58   0.55   -0.30   0.00
6000   -0.31   -0.56   -0.31   -0.65
8000   -0.31   -0.95   -0.31   -0.98
10000   0.00   -1.29   -0.67   -0.67
12000   0.00   -1.33   -0.67   -1.02
14000   0.00   -1.33   -1.07   -1.07
16000   -0.69   -0.37   -1.07   -1.07
18000   -0.76   -0.37   -1.11   -1.51
20000   -1.11   -1.07   -1.51   -1.16

EDIT:  When I first posted the table I got some signs wrong.  Have corrected it now.

So what's the big difference between the BBDs if the gains match so well?
Well based on my experience of taking the measurements using a DSO, when the clock rates get low and the audio frequency gets high, the output waveform on the BL3207 looks much nicer than the one from the SAD1024.  e.g. the BL3207 output still resembles a sine wave while the SAD1024 is outputing a mess!!!  That made taking some of the SAD1024 measurements hard.
The messy waveform is partly down to the lower clock rate and lack of balance trimmer, but I think there might be something else going on.  I noticed that when the BL3207 output eventually starts to distort, the output sine wave looked kind of triangular (i.e. pointy tops and bottoms, and you could still sort of see the sine wave).
When the SAD1024 output started to distort, the output wave looked kind of square (i.e. "flat tops and bottoms").  Now I know that both the triangle and square harmonic series consist of odd harmonics but in different ratios, so maybe the difference in these chips is in the distortion.  I wonder if the "clarity" people are hearing in the SAD1024 is actually down to the harmonic content coming from the distorted waveform?
Title: Re: EM3207 (v1.1) - MN3207 based EHX Electric Mistress (9V) clone
Post by: rankot on January 28, 2020, 01:18:40 AM
Did you have time to adjust schematic to your findings and do a hearing comparison with both?
Title: Re: EM3207 (v1.1) - MN3207 based EHX Electric Mistress (9V) clone
Post by: DrAlx on January 28, 2020, 03:26:56 AM
No, and the whole point of going through the above process and getting the numbers was to avoid a subjective comparison.

The EM3207 still has other differences in the audio path (e.g. input section with gain boost), and the LFO sweeps differently to the V2 (range is different and waveform is rounded off so it less triangular), making it hard to set up two circuits the exact same way.

EDIT: If you make these changes to Thomeeque's schematic


the result will be similar to V6 EM, but with boost at input.

http://www.metzgerralf.de/elekt/stomp/mistress/images/1981-electric-mistress-v6-schematic.gif
Title: Re: EM3207 (v1.1) - MN3207 based EHX Electric Mistress (9V) clone
Post by: rankot on January 28, 2020, 04:07:02 AM
No, and the whole point of going through the above process and getting the numbers was to avoid a subjective comparison.

The EM3207 still has other differences in the audio path (e.g. input section with gain boost), and the LFO sweeps differently to the V2 (range is different and waveform is rounded off so it less triangular), making it hard to set up two circuits the exact same way.

EDIT: If you make these changes to Thomeeque's schematic

  • Change (R12, R13, R14, C7) from (4k7, 4k7, 47k, 680nF) to (470, 470, 10k, 3n3).
  • Remove Q1 and R15 completely.
  • Connect the top of C7 directly into C8.

the result will be similar to V6 EM, but with boost at input.

http://www.metzgerralf.de/elekt/stomp/mistress/images/1981-electric-mistress-v6-schematic.gif

Great, thanks! I will certainly try that. I have bought a PCB for 3207 version from another board member, and was just thinking to populate it few days ago, but decided to wait when I saw this post.  :)
Title: Re: EM3207 (v1.1) - MN3207 based EHX Electric Mistress (9V) clone
Post by: PRR on January 28, 2020, 08:08:41 PM
> Posted before completed typing....

The (https://www.diystompboxes.com/smfforum/Themes/DIYTheme2/images/icons/modify_inline.gif) Modify button below (and above) your post allow you to finish-off an incomplete post.

There is some time-limit, but usually long enough to correct an "ooops".
Title: Re: EM3207 (v1.1) - MN3207 based EHX Electric Mistress (9V) clone
Post by: 12Bass on January 28, 2020, 08:49:39 PM
So what's the big difference between the BBDs if the gains match so well?
Well based on my experience of taking the measurements using a DSO, when the clock rates get low and the audio frequency gets high, the output waveform on the BL3207 looks much nicer than the one from the SAD1024.  e.g. the BL3207 output still resembles a sine wave while the SAD1024 is outputing a mess!!!  That made taking some of the SAD1024 measurements hard.
The messy waveform is partly down to the lower clock rate and lack of balance trimmer, but I think there might be something else going on.  I noticed that when the BL3207 output eventually starts to distort, the output sine wave looked kind of triangular (i.e. pointy tops and bottoms, and you could still sort of see the sine wave).
When the SAD1024 output started to distort, the output wave looked kind of square (i.e. "flat tops and bottoms").  Now I know that both the triangle and square harmonic series consist of odd harmonics but in different ratios, so maybe the difference in these chips is in the distortion.  I wonder if the "clarity" people are hearing in the SAD1024 is actually down to the harmonic content coming from the distorted waveform?
Is it possible that the SAD1024 exhibits a greater optimal bias voltage shift in order to retain a low distortion output?  I noticed that optimal bias changed somewhat depending on frequency with my SAD1024 A/DA flanger.  I set it to be best at the "sweet spot" in the sweep, which is somewhere around 1ms IIRC (not sure of the clock frequency).  I definitely noticed the gain went down a bit at the highest clock rates.  But its delay path sounded surprisingly high fidelity (not distorted).  Perhaps try optimizing the bias for somewhere nearer the middle of the range.  Note that I use past tense because my friend's son knocked it off of my amp a few months ago and I think that the SAD1024 may have died as a result and I haven't had the heart to troubleshoot beyond confirming that the clean path still works and the delay path is dead.
Title: Re: EM3207 (v1.1) - MN3207 based EHX Electric Mistress (9V) clone
Post by: DrAlx on January 29, 2020, 03:00:31 AM
The max clock in my test corresponds to 1.28 ms and I set bias for that.
You would not hear the distorted waveforms I was seeing as what you would call a distorted sound because only the highest audio frequencies (above several kHz) see the effect, and only at the lowest end of the sweep. So all additional harmonic content in the distortion would be above 10kHz.
Title: Re: EM3207 (v1.1) - MN3207 based EHX Electric Mistress (9V) clone
Post by: 12Bass on January 29, 2020, 07:25:38 AM
The max clock in my test corresponds to 1.28 ms and I set bias for that.
You would not hear the distorted waveforms I was seeing as what you would call a distorted sound because only the highest audio frequencies (above several kHz) see the effect, and only at the lowest end of the sweep. So all additional harmonic content in the distortion would be above 10kHz.
When I was listening, I used full range music with lots of high frequency content and listened with AKG K702s.  My flanger also has considerably relaxed filtering before and after the BBD which works very well (very open/clear sounding) at higher clock rates but aliasing becomes an issue as the delay time increases.  That's not much of a problem for me because my favorite flanging sounds are probably in the 0.5ms - 4ms range.  Delay path fidelity was surprisingly high (close to bypassed sound) at high clock rates.  15ms sounded more "grungy" and low-fi and the BBD gain was noticeably higher as well.  Didn't look at the waveform on a scope, however.  Would still suggest optimizing the SAD1024 bias for a lower clock rate and see how that affects the output waveform.
Title: Re: EM3207 (v1.1) - MN3207 based EHX Electric Mistress (9V) clone
Post by: DrAlx on January 29, 2020, 08:06:56 PM
I repeated the comparison test but this time set bias levels for both BBDs with clock at lowest frequency (25kHz on SAD1024, 50kHz on BL3207).
Setting optimum bias level for lowest clock frequency meant I was starting to see clipped outputs on both BBDs when testing with the fastest clocks, so I had to lower the signal level when that happened to keep the output waves looking nice and measurable.

Another change I made to each BBD was to add a 1k trimpot between BBD outputs to minimise clock glitches.  I set those trimmers at the start of the test when the clock was at bottom of range.

End result (table below) was that I had even better agreement between chips than in the first test.
Not sure if that was because of trimmers or different bias set up.

Audio (Hz)50kHz100kHz200kHz400kHz
1000.000.000.000.38
2000.000.000.000.38
4000.380.000.380.00
8000.000.000.00-0.45
10000.000.000.000.00
20000.000.00 0.00-0.28
40000.000.00-0.33-0.43
60000.000.00-0.35-0.45
80000.000.00-0.37-0.71
100000.00-0.09-0.37-0.74
120000.000.00-0.39-0.76
140000.000.00-0.40-0.78
16000-0.400.00-0.43-0.80
18000-1.340.00-0.450.00
20000-1.59-1.27-0.88-0.86

So leaving out Q1 in this circuit gives a favourable comparison between chips (less than 1dB difference in wet path for most frequencies) at both ends of the bias range.  Probably is good for all other bias levels in between too.
Most people can't hear a 1 dB change in volume (I know I can't). 
Try this... https://www.audiocheck.net/blindtests_level.php?lvl=1

That's why I think any audible difference (if there is any) must be coming from extra harmonic content. 
Once sampling rate gets too low or audio frequency gets too high, sine wave input gives following "knobbly sine wave" output from BL3207 ... (sorry for bad quality pics). 

https://1drv.ms/u/s!AvrH61utWEtEi3TYLtqa1xsT9sxz?e=8xT6Rv

while the SAD1024 with 1/2 the sample rate outputs something that does not really look much like a sine wave ...

https://1drv.ms/u/s!AvrH61utWEtEi3O-leEl9cKYEeic?e=eL6BDm

Boxier shape has stronger harmonic content than triangular shape.  In fact I am not even sure it's fair to talk about "BBD gain" of a signal once the output waveform looks different to the input waveform.

Running SAD1024 in parallel mux will no doubt make the SAD1024 output look like the BL3207.
Title: Re: EM3207 (v1.1) - MN3207 based EHX Electric Mistress (9V) clone
Post by: rankot on January 30, 2020, 04:07:27 AM
Boxier shape has stronger harmonic content than triangular shape.  In fact I am not even sure it's fair to talk about "BBD gain" of a signal once the output waveform looks different to the input waveform.
Running SAD1024 in parallel mux will no doubt make the SAD1024 output look like the BL3207.

To me, it just seems to be the sampling rate difference. Did you try to run 3207 at 25kHz?
Title: Re: EM3207 (v1.1) - MN3207 based EHX Electric Mistress (9V) clone
Post by: DrAlx on January 30, 2020, 07:55:20 AM
Yes, SAD1024 waveform is clearly undersampling the audio.
I have not checked the BL3207 at low rate yet but I'm sure it will do the same thing.

EDIT: I just realised a better comparitive test is to measure signal at the output of my test load (i.e. what corresponds to the "mix point" in the EM) rather than at the BBD output.  I'd probably see waveforms that look closer to sine waves if I did that.

Title: Re: EM3207 (v1.1) - MN3207 based EHX Electric Mistress (9V) clone
Post by: rankot on January 30, 2020, 02:51:05 PM
However, could you try to test 3207 running at 25kHz?
Title: Re: EM3207 (v1.1) - MN3207 based EHX Electric Mistress (9V) clone
Post by: DrAlx on January 30, 2020, 03:59:37 PM
Tested it.  BL3207 does same thing at 25 kHz as SAD1024 at 50kHz.

Measuring at "mix point" makes the messy waveforms look much more like sine waves (step artefacts are gone) but because the signal is also weaker there it is harder to take good measurements with my simple scope. As far as I can tell, pk-pk voltages from the two BBDs are in just as good agreement as when they were measured at the BBD output (as they should be).

Since the steps in the waveform don't reach the circuit output (the 470 + 47n at the final mix point kills them) it means what I was thinking about harmonics making a difference could not possibly be correct.
Therefore based on my measurements, I can't see how using an SAD1024 vs a BL3207 in this circuit could make a significant difference to the sound, unless there is something I cannot measure (e.g. the noise levels), or if I measured things badly.

Feedback (the color pot) could have an effect since any differences in gain between chips would be amplified.  e.g. the same color pot setting might cause one chip to oscillate but not the other.

In any case, if you want the EM3207 to be a more authentic sounding clone of the original, make the changes I mentioned above and remove Q1.   Without my changes, the wet path will be stronger than an original EM for all frequencies, getting up to over 3.5 dB stronger by 10 kHz as in this picture...

http://photobucket.com/albums/ag185/DrAlx/Graph1_zpsvzhjbxmg.png

That increased BBD gain for high audio frequencies (which is not in the original EMs) has the effect of making the hiss level on the pedal louder too.
Title: Re: EM3207 (v1.1) - MN3207 based EHX Electric Mistress (9V) clone
Post by: DrAlx on January 31, 2020, 03:51:02 AM
Also forgot to mention two other resistor changes when you drop Q1.
Change R16 and R18 in Thomeeque's schematic to 13k and 8k2 so that it matches the V6 that the EM3207 is aiming to copy...

http://www.metzgerralf.de/elekt/stomp/mistress/images/1981-electric-mistress-v6-schematic.gif

So the full set of changes is:


   
   
Title: Re: EM3207 (v1.1) - MN3207 based EHX Electric Mistress (9V) clone
Post by: Stasss on February 03, 2020, 02:44:58 AM
I'm planning to build this one.
 C8=47nFor82nF?
Title: Re: EM3207 (v1.1) - MN3207 based EHX Electric Mistress (9V) clone
Post by: DrAlx on February 03, 2020, 09:56:19 AM
Leave it at 82n so it matches the audio path of the V6 Electric Mistress in the link.

All my tests used a test load based on the V2 EM circuit (which has some different R and C values) but that is not significant.
I would get the same good agreement between BBDs if I had used a test load based on the V6 circuit.
I only used a V2 test load because I wanted to make sure my new measurements agreed with measurements I carried out a couple of years ago using the V2 audio path.

Title: Re: EM3207 (v1.1) - MN3207 based EHX Electric Mistress (9V) clone
Post by: Ben N on February 03, 2020, 04:05:40 PM
Is there a "current" (get it?) source of boards?
Title: Re: EM3207 (v1.1) - MN3207 based EHX Electric Mistress (9V) clone
Post by: DrAlx on February 04, 2020, 02:48:18 AM
I have not tested a 3007 chip. The data sheet for the 3007 chip shows 0dB insertion gain compared to the 2dB insertion gain of the 3207. I take that gain to refer to the case when load resistance is very high (e.g. over 47k).

Part of the reason I got good comparison between 3207 and SAD1024 was that 10k load on the 3207 chip lowered the BBD gain so that it matched the SAD1024 with 10k load.  That was a lucky find that I did not expect.  I suspect that 10k load on a 3007 chip would give BBD gain that is 2dB lower than the SAD1024. If that's the case then the circuit mods I describe would make a 3007 based EM clone worse (i.e. wet path too weak by 2dB).

BTW, I did not mention this but when comparing 3207 vs SAD1024 with large input voltage (so I could set bias levels) I found that they had similar clipped wave forms at both ends of the clock range.  In other words max input signal level before distortion was similar between chips in this circuit config.
Title: Re: EM3207 (v1.1) - MN3207 based EHX Electric Mistress (9V) clone
Post by: Stasss on February 10, 2020, 02:24:23 AM
Thanks a lot DrAlx!
 This is very close to the original! Great sounding flanger. I have only one thing to say: It would be great to add a ¨depth¨ control  to have more control. If there is any idea please publish it here.
Title: Re: EM3207 (v1.1) - MN3207 based EHX Electric Mistress (9V) clone
Post by: Amitay3333 on October 16, 2020, 10:01:24 AM
Hii guys, I want to make a *Deluxe* Mistress V4-V5 reissue clone the one with the RD5106A in it, is it possible to fit MN3007 instead?
I searched a lot and didn't find a V4-V5 Deluxe clone maybe someone can help me in here.
The Reissue uses 12v...



Regards and healthiness
Amitay Kehaty.
 
Title: Re: EM3207 (v1.1) - MN3207 based EHX Electric Mistress (9V) clone
Post by: Ben N on October 18, 2020, 08:04:20 AM
אחלה! זה המקום, אחי, כאן תמצא את המומחים.
Title: Re: EM3207 (v1.1) - MN3207 based EHX Electric Mistress (9V) clone
Post by: Thomeeque on October 19, 2020, 03:29:47 AM
You can try to check EM3007 (https://www.diystompboxes.com/smfforum/index.php?topic=91981.msg798618#msg798618) project - it was my attempt to retrofit 9V EM with MN3007. Circuitry of modern DEM with RD5106A is almost identical with 9V EM and it was one of the resources I used. Besides modifications connected with different BBD being used (network around MN3007 chip and 4049 clock signal booster) there will be only minor differences. EM3007 can be powered by up to 15 volts (MN3007 limit). Please note, I have never built EM3007 myself and it was a long time since I tackled this topic. But I did quick search now and I've found this post:

Just a thought, but have you tried running it at 12V? I have an EM3007 clone that really doesn't like being on 9V. Noise, squealing, which forced a rather short sweep, in my case. Feeding it 12V solved everything for me.

 So it seems like strungout successfully built/verified it.

 Good luck, T.
Title: Re: EM3207 (v1.1) - MN3207 based EHX Electric Mistress (9V) clone
Post by: Mark Hammer on December 09, 2020, 03:33:00 PM
Finally discovered a solder bridge that had been preventing the circuit working, all these years, and fired it up.  Simply wonderful.

One thing I will note, in case it hasn't been mentioned yet, is that anyone wanting CW to produce faster sweep rates should use a C-taper 1M pot.

At present, I don't have much use for the Filter Matrix mode, but I may consider use of an envelope follower and LDR in parallel with the Range control to get envelope-swept flanging.  That's down the road, though.  My hunch is that Filter-Matrix mode was originally intended to be used with the EHX Hot Foot controller to get "manual" flanging.

Another point to mention is the importance of the 22k clock trimmer.  Critical in nailing the kind of tone you want.

Finally, I connected a 47pf cap in parallel with the 22pf clock cap and found I could get a very nice Leslie-like gurgle.  Since  increasing the delay range has a tendency to make things a little more boing-ey, one is well advised to turn the Range control way down to make sounds more palatable.

A belated big thanks to thomeeque for a terrific circuit and layout.  I have a couple of big-box Deluxe Electric Mistresses sitting here that a friend asked me to fix.  I'll have to see how the 3207-based circuit fares against a Reticon-based unit.  I'm not expecting miracles, but you never know.
Title: Re: EM3207 (v1.1) - MN3207 based EHX Electric Mistress (9V) clone
Post by: Mark Hammer on December 10, 2020, 03:51:41 PM
Didn't get around to the DEMs yet, but I have a vintage TC  Stereo Chorus/Flanger, and I far prefer the Thomeeque circuit to the TC.
Title: Re: EM3207 (v1.1) - MN3207 based EHX Electric Mistress (9V) clone
Post by: jyka on February 04, 2021, 12:46:58 PM
Hello :)

Is thit possible to cancel the switch to keep the flange position ?

Jyka
Title: Re: EM3207 (v1.1) - MN3207 based EHX Electric Mistress (9V) clone
Post by: MisterMocha on July 20, 2021, 09:20:42 AM
I recently finished a PCB design that functions as a drop-in replacement for the SAD1024 in vintage EM flangers. The replacement uses two MN3009s in series to match the 512 stages used in the original EMs (it's weird that they basically use half of the SAD1024). The PCB also has a built in Mosfet driver as a clock buffer and some additional circuitry to match the output impedance of the SAD1024.

I tweaked the sound by building a V2 EM circuit on a breadboard and switching between an original SAD1024 and my replacement circuit.

Some renders from Kicad:
(https://i.postimg.cc/YLwY167R/V4.png) (https://postimg.cc/YLwY167R)

(https://i.postimg.cc/XBcFxr7b/V4wonk.png) (https://postimg.cc/XBcFxr7b)

The bare sets of 8 pads are for the MN3009s

I found this thread a while ago and it really inspired me to take on this project so I thought the folks here might be interested in the work that I've done on the topic