9V Electric Mistress retrofit with MN3007

[Scruffie]

Wow that's nice... weirdly i've found MN3207 harder to come by and more expensive in the U.K but maybe that's just me.

Still that looks like an awesome project, i've been looking for a small flanger to build and that looks pretty tight to me.

[Just1More]

What exactly do you plan to do? Complete build of original (SAD1024) version of EM9V (Markus W. layout?) + this retrofit? Or you have already SAD1024 version completed and you need only SAD1024 replacement?

Hi Tomeeque.  I'm planning on doing the EM9V (Markus W. layout) + this retrofit.  Your new project looks very cool.  Looks like a nice compact layout.  I've already got most of the parts for the other build and John Lyons is in the process of making up the boards for me so I'll probably just go ahead with that for now.

Thanks to both you and Dave for your work on this so far.

[Thomeeque]

flangers are blooming these days! Good to know!
Thomeeque, that board looks awesome!

^^whoa! Eagerly awaiting your results.

Wow that's nice... weirdly i've found MN3207 harder to come by and more expensive in the U.K but maybe that's just me.

Still that looks like an awesome project, i've been looking for a small flanger to build and that looks pretty tight to me.

 Thank you guys for the compliments and for your interest! I'll keep you updated..

weirdly i've found MN3207 harder to come by and more expensive in the U.K but maybe that's just me.

 Oh, I hope so, I did pick MN3207 as the cheapest and the most widely available BBD chip, it would be bummer if it started to vanish..

Hi Tomeeque.  I'm planning on doing the EM9V (Markus W. layout) + this retrofit.  Your new project looks very cool.  Looks like a nice compact layout.  I've already got most of the parts for the other build and John Lyons is in the process of making up the boards for me so I'll probably just go ahead with that for now.

Thanks to both you and Dave for your work on this so far.

 Sure, you're welcome Good luck and please let us know, when you're finished with the build - as this is still very "young" project (two builds so far?), every feedback is interesting!

 Btw. one request in advance (for every builder of this retrofit): when you'll get to measurements of the clock circuitry, note somewhere the highest clock frequency you've been able to dial (if you'll have chance to measure it of course) and let me/us know. AFAIK Dave was able to get slightly above 1MHz (1.08?) even when trying different parts, my EM3207 gets to 1.2MHz max. (again independently on used parts), maybe it's partly layout dependent..? It would be interesting to know..

 Cheers, T.

[Scruffie]

 Thank you guys for the compliments and for your interest! I'll keep you updated..

weirdly i've found MN3207 harder to come by and more expensive in the U.K but maybe that's just me.

 Oh, I hope so, I did pick MN3207 as the cheapest and the most widely available BBD chip, it would be bummer if it started to vanish..

I look forward to your updates! 

Yeah, it's probably more available so it makes sense to pick the 3207 especially with the V3207 still being in production by Cool Audio & the BL3207.

It's more that on ebay I can pick up 5 MN3007s for £5-6 but for MN3207s it seems to be about £10 (and there are alot less of them) but alot of the 3007s are probably fakes etc. it's probably just a case of location, I can easily get 3207s from Smallbear anyway.

[oldschoolanalog]

Nice compact design Tomas

...Dave was able to get slightly above 1MHz (1.08?) even when trying different parts, my EM3207 gets to 1.2MHz max. (again independently on used parts), maybe it's partly layout dependent..?

What value did you use for C19?  I used 10pF silver mica 1%. In the component layout pic the value shown is 47pF. I can't see the actual value of C19 on the board in your pic. If you used 10pF maybe the difference is in component tolerance(?).
FWIW/IMHO, a 1MHz clock is more than enough for this (EM) circuit. It was never intended to be clocked into A/DA territory.
What is needed is for somebody who owns an EH/EM (any flavour, 9V, "Deluxe", whatever) to step up and take some clock measurements. This is one commercial flanger I no longer have in my collection. If I had one I would have done this a long time ago. I've stepped up & opened up my A/DA, MXR, Ross, etc. to take readings for the sake of R&D. Time for somebody else to follow suit.
C'mon, somebody has to have an EH/EM; or access to one (friend, band member, whatever). Please?
@Tomas: Could you post a schematic "snippet" that shows the changes you made?
Thanks!

[Just1More]

Btw. one request in advance (for every builder of this retrofit): when you'll get to measurements of the clock circuitry, note somewhere the highest clock frequency you've been able to dial (if you'll have chance to measure it of course) and let me/us know. AFAIK Dave was able to get slightly above 1MHz (1.08?) even when trying different parts, my EM3207 gets to 1.2MHz max. (again independently on used parts), maybe it's partly layout dependent..? It would be interesting to know..

Will do.  [Patiently waiting for parts to arrive...]

[Thomeeque]

Nice compact design Tomas

 Thanks Dave!

...Dave was able to get slightly above 1MHz (1.08?) even when trying different parts, my EM3207 gets to 1.2MHz max. (again independently on used parts), maybe it's partly layout dependent..?

What value did you use for C19?  I used 10pF silver mica 1%. In the component layout pic the value shown is 47pF. I can't see the actual value of C19 on the board in your pic. If you used 10pF maybe the difference is in component tolerance(?).

 It's an ordinary 15pF ceramic disc now - but I've tried different 10 to 33pF caps (IIRC) with no influence at maximal possible clock achievable (even for 33pF I was able to dial 1.2MHz by clock trimmer - IIRC again, it's 4 months ).

==============================================
 I should probably state at this place that by working clock I mean whole clock generator circuitry up to BBD clock inputs working - LM311 stage is able to tick at higher frequencies, but 4013 is not able to process more than 1.2MHz (in my case - even when trying different 4013 brands/types) at outputs.
==============================================

FWIW/IMHO, a 1MHz clock is more than enough for this (EM) circuit. It was never intended to be clocked into A/DA territory.

 Yes, I agree (but some headroom for experiments would be nice, right? )

What is needed is for somebody who owns an EH/EM (any flavour, 9V, "Deluxe", whatever) to step up and take some clock measurements. This is one commercial flanger I no longer have in my collection. If I had one I would have done this a long time ago. I've stepped up & opened up my A/DA, MXR, Ross, etc. to take readings for the sake of R&D. Time for somebody else to follow suit.
C'mon, somebody has to have an EH/EM; or access to one (friend, band member, whatever). Please?

 Yes, please!

@Tomas: Could you post a schematic "snippet" that shows the changes you made?

 Anything you say, Dave!



600DPI version for printing

Thanks!

 You're welcome, thanks for feedback! T.

Btw. one request in advance ..

Will do.  [Patiently waiting for parts to arrive...]

 Thank you (in advance )! T.

[12Bass]

Great work!

Did you ever finish the schematic for the MN3007?  Suppose it could be drawn from the MN3207 version with a few changes....

[Thomeeque]

Great work!

Did you ever finish the schematic for the MN3007?  Suppose it could be drawn from the MN3207 version with a few changes....

 Thanks!

 I did never start actually , but it would be really easy - switch R9 & R10 values and pins 1 & 5 of IC2 and you're there, at least theoretically - but please note, this schemo is not final (what I don't like for 100% yet is LPF filtering at BBD's output and dry/wet mix ratio), even the changes should be minor already.

 T.

[Scruffie]

While we're here... just thought i'd bring this thread back up http://www.diystompboxes.com/smfforum/index.php?topic=46157.0

Perhaps we could combine Thomeeques MN3207 Electric Mistress with that and have the first simple, available chips, cheap TZF flanger project 

[Just1More]

The original project docs don't seem to have a layout showing part references.  The values are shown but this makes it hard to identify parts on the schematic when there are 4 resistors with the same value.

I've retraced and redrawn the layout for the MN3007 retrofit which I think is correct.  I based the retrofit board connections on the photos from oldschoolanalog's build since I haven't built this myself yet (not far away now though).

Can someone who has already built this please check what I've done and let me know if you see any mistakes: Electric Mistress MN3007 retrofit layout (click the image to see full size).  Hopefully this will make it a bit easier for others to pick up and run with.  I'll try to do an updated schematic soon as well.

Thanks

[DLC86]

First thing: Hi everybody, this is my first post! I registered today, but if I started reading this forum a few years ago and I've learnt lots of things from you...

to Just1More: I checked your layout and it seems ok to me, I just haven't found where you read about leaving out R20 & R21
    Then a question: why didn't you use oldschoolanalog's components values for the retrofit?

to Thomeeque: why don't you make a PCB layout for the 3207 retrofit?  

     Thanks everyone  

[Just1More]

First thing: Hi everybody, this is my first post! I registered today, but if I started reading this forum a few years ago and I've learnt lots of things from you...

to Just1More: I checked your layout and it seems ok to me, I just haven't found where you read about leaving out R20 & R21
    Then a question: why didn't you use oldschoolanalog's components values for the retrofit?
...

Hi DLC86.  Thanks for checking the layout and welcome to the forum.

Right back in the very first post Thomeeque shows a segment of the Tonepad schematic.  R20 (on Markus' schematic) is replaced with a jumper and R21 is left out entirely.  Oldschoolanalog has a good summary of other changed/deleted values in this post.

Why did I use oldschoolanalog's component values?  No real reason - as good a place to start as anywhere.  I haven't had the time to build this yet and I'm still waiting on some parts to arrive.  I might be able to comment further on the values once that's done.

[Thomeeque]

I've retraced and redrawn the layout for the MN3007 retrofit which I think is correct.  I based the retrofit board connections on the photos from oldschoolanalog's build since I haven't built this myself yet (not far away now though).

Can someone who has already built this please check what I've done and let me know if you see any mistakes: Electric Mistress MN3007 retrofit layout (click the image to see full size).  Hopefully this will make it a bit easier for others to pick up and run with.  I'll try to do an updated schematic soon as well.

Thanks

 Hi John!

 Impressive work! However I cannot check it properly (I did not build it ), I have just one small note - as I advice in the first post, I would not feed it from SAD socket - even Dave proved that it is nothing crucial actually, I would still advice to feed it this way as it should minimize risk of unwanted interferences between retrofit and rest of the circuit via feeding tracks.

 Good luck, T.

to Thomeeque: why don't you make a PCB layout for the 3207 retrofit?  

 I've saved this task for *YOU* T.

[Just1More]

Hi John!

 Impressive work! However I cannot check it properly (I did not build it ), I have just one small note - as I advice in the first post, I would not feed it from SAD socket - even Dave proved that it is nothing crucial actually, I would still advice to feed it this way as it should minimize risk of unwanted interferences between retrofit and rest of the circuit via feeding tracks.

 Good luck, T.

Thanks Tomas.  I'll factor in your suggestions as I eventually get around to building it.

Other than comparing the PCB layout against the schematic I can't take much credit.  I've collected a set of component libraries for Inkscape that have been contributed by other members at various times.  I'm pretty artistically challenged - but I'm ok at recycling and reusing stuff 

[mongo]

 I know this is maybe slightly off topic but I have a non working original EM, and before trying to make this mod I'd like to bring it back to life!

 just to be sure, what would be the proper Zener diode in this unit?  some schems I've seen call for a 1n961B, other call for something different. Please, Any advice?

 My EM is a non deluxe 18v unit.

 THANKS IN ADVANCE!

 Andy

 (sorry if I hijacked the thread, if anyone has any advice please respond in PM)

[DLC86]

Right back in the very first post Thomeeque shows a segment of the Tonepad schematic.  R20 (on Markus' schematic) is replaced with a jumper and R21 is left out entirely.  Oldschoolanalog has a good summary of other changed/deleted values in this post.

Oh, you're right, I din't see it
Now I'm gonna order parts for your layout and when it's done I'll let you know how it works, but I'd want to try the 3207

I've saved this task for *YOU* T.

Ok, I'll try, but it's not a good idea, I'm not very expert...  
The only differences between 3007 and 3027 are in the retrofit (R9, R10 and pins 1 & 5), right? Or will I have to change some components even in the main board?
Thanks

[DLC86]

switch R9 & R10 values and pins 1 & 5 of IC2 and you're there, at least theoretically

Probably I'll do a stupid question but, why do you say to switch pins 1 and 5? I saw that 3207 and 3007 have the same pinout 

[Thomeeque]

switch R9 & R10 values and pins 1 & 5 of IC2 and you're there, at least theoretically

Probably I'll do a stupid question but, why do you say to switch pins 1 and 5? I saw that 3207 and 3007 have the same pinout 

 If you want to use MN3207 instead of MN3007 (anywhere, not just here), you have to use it kind of upside-down. Pinout is same, basic internal circuitry is same as well, but where MN3007 uses P-channel FETs, MN3207 uses N-channel FETs. Check datasheets, you will see that where MN3007 expects negative voltage (V_DD, V_GG, V_BIAS), MN3207 expects positive voltage (relative to chip's GND node).

 And here I see that I have forgot one important TODO for use of MN3007 in my EM3207:

switch R9 & R10 values and pins 1 & 5 of IC2 and hook R11 to V_CC instead of GND and you're there, at least theoretically..

 T.

[DLC86]

If you want to use MN3207 instead of MN3007 (anywhere, not just here), you have to use it kind of upside-down. Pinout is same, basic internal circuitry is same as well, but where MN3007 uses P-channel FETs, MN3207 uses N-channel FETs. Check datasheets, you will see that where MN3007 expects negative voltage (V_DD, V_GG, V_BIAS), MN3207 expects positive voltage (relative to chip's GND node).

 And here I see that I have forgot one important TODO for use of MN3007 in my EM3207:

switch R9 & R10 values and pins 1 & 5 of IC2 and hook R11 to V_CC instead of GND and you're there, at least theoretically..

 T.

Ok thanks.
I've done the layout following your instructions, but I just modified the 3007's one because I'm too lazy and ignorant to make a new layout.
Here are the PCB and the layout for MN3207 retrofit. Please check'em and let me know if they're ok 
http://img203.imageshack.us/i/sad1024retrofitmn3207pc.jpg/
http://img220.imageshack.us/i/sad1024retrofitmn3207lo.jpg/