Hello All,
In spirit of all the cool projects being created, i thought i would share my Deluxe Memory Man work-alike. The motivation behind this project was to use the MN3008 BBD, which is easier to get than the MN3005 (although this won't be true soon enough). Also, SmallBear is selling counterfeit MN3008 pairs (pictured below) at a reasonable price. Its a tough project, so good luck!
Here is the project file : Deluxe Micro Man Rev A (http://youngpedals.com/Deluxe_Micro_Man_Rev_A.pdf)
Pics:
(http://farm4.static.flickr.com/3334/5729271024_537def4634.jpg)
(http://farm6.static.flickr.com/5069/5731615119_779930993a.jpg)
(http://farm3.static.flickr.com/2491/5729271020_a54be3ecd9.jpg)
Short clip: http://soundcloud.com/youngpedals/deluxe-micro-man
Thanks for sharing this nice project "over here".
Your efforts are very much appreciated!
:icon_smile:
You do nice mechanical design!
I would love to see this reworked for 3208! :) :icon_rolleyes:
Quote from: oldschoolanalog on July 22, 2011, 08:27:19 PM
Thanks for sharing this nice project "over here".
Your efforts are very much appreciated!
:icon_smile:
Quote from: Processaurus on July 23, 2011, 06:35:57 AM
You do nice mechanical design!
Thanks!
Quote from: Ummagumma on July 23, 2011, 11:09:28 AM
I would love to see this reworked for 3208! :) :icon_rolleyes:
It would be quite easy since i used a positive supply. At a minimum you would simply replace the 7815 with a 7809. Looks like you would have to lower R1/R2 since they set the DC bias of the compressor portion of the compander. 47k/47k would probably work (the datasheet has the equation).
EDIT: you would have to swap the supply pins in the layout. I always forget that MN320X/MN300X have opposite supply pins!
Nice project! As I have some MN3008's still lying around, I might give this a try....
What is C46 (DNI ??) for? I did not see it in the picture...
Thanks for contributing this.
Maarten
Quote from: rustypinto on July 23, 2011, 11:49:56 AM
Quote from: oldschoolanalog on July 22, 2011, 08:27:19 PM
Thanks for sharing this nice project "over here".
Your efforts are very much appreciated!
:icon_smile:
Quote from: Processaurus on July 23, 2011, 06:35:57 AM
You do nice mechanical design!
Thanks!
Quote from: Ummagumma on July 23, 2011, 11:09:28 AM
I would love to see this reworked for 3208! :) :icon_rolleyes:
It would be quite easy since i used a positive supply. At a minimum you would simply replace the 7815 with a 7809. Looks like you would have to lower R1/R2 since they set the DC bias of the compressor portion of the compander. 47k/47k would probably work (the datasheet has the equation).
EDIT: you would have to swap the supply pins in the layout. I always forget that MN320X/MN300X have opposite supply pins!
I never noticed you swapped the power arrangement... not a bad idea... I see you simplified a few parts aswell.
I recon with 2 x 3205s (instead of 4 x 208s) I might be able to shoe horn it into a 1590BB with onboard pots and no stand up resistors... running at 9V the bridge rectifier and regulator could happily be dropped and a zener used in its place to give the BBDs that slightly lower voltage they prefer (and allow for people to run the opamps at 12V should they prefer while protecting the BBDs) then as you say, just a case of swapping the pin arrangements and the compander resistors.
Cheers for the inspiration! 3205 Memory man here I come :icon_mrgreen:
One slight edit... to that, VGG should be 14/15 so to save on having a voltage reference i'd add a diode to each to drop VGG by 0.6V... close enough to 14/15th of 9Vs.
What about the outputs of the BBDs though... would they go to ground now instead or am I going insane.
Bookmarked! ;)
Very generous contribution and great PCB design. I would not be man enough to tackle that on a single-sided board.
Quote from: maarten on July 23, 2011, 12:14:56 PM
Nice project! As I have some MN3008's still lying around, I might give this a try....
What is C46 (DNI ??) for? I did not see it in the picture...
Thanks for contributing this.
Maarten
I think that stands for Do not install, the cap's in parallel with the clock cap so it's probably for experimental purposes.
Beautiful!
you're my hero and muse
Heck Yeah
Excellent!
Such a well put together project,thanks for sharing.
QuoteI never noticed you swapped the power arrangement... not a bad idea... I see you simplified a few parts aswell.
I recon with 2 x 3205s (instead of 4 x 208s) I might be able to shoe horn it into a 1590BB with onboard pots and no stand up resistors... running at 9V the bridge rectifier and regulator could happily be dropped and a zener used in its place to give the BBDs that slightly lower voltage they prefer (and allow for people to run the opamps at 12V should they prefer while protecting the BBDs) then as you say, just a case of swapping the pin arrangements and the compander resistors.
Cheers for the inspiration! 3205 Memory man here I come :icon_mrgreen:
One slight edit... to that, VGG should be 14/15 so to save on having a voltage reference i'd add a diode to each to drop VGG by 0.6V... close enough to 14/15th of 9Vs.
What about the outputs of the BBDs though... would they go to ground now instead or am I going insane.
I was never a fan of shunt regulators for analog delays, but it is certainly possible to save space. The problem is making the supply pins happy while dealing with the current requirements of the clock/CD4047, which changes over the full range of 100kHz-10kHz. The regulator method is more stable. Even if you use 12VDC on the op-amps, you can get away with a 78L09 powering the BBD's/clock, which is not terribly space constraining.
I tried to speak a little bit about VGG in my design notes. The datasheet specifies it to be 14/15V away from Vdd, but it still works if Vgg = Vdd. If you use the bias scheme i did, you can't get away with a simple diode or resistor drop because the voltage is in the wrong direction. You have to use a resistor divider to create ~1V with this scheme. I did breadboard it with both the resistor divider and where Vgg = Vdd, and i could not hear any difference at all. I remember reading an old BBD app note (Panasonic or Reticon?) that explained this pin in more detail, and mentioned that Vgg could be the same as Vdd for convenience (and it sure was convenient for the density of this layout), but said ideally it should be ~1V away from the supply.
Quote from: maarten on July 23, 2011, 12:14:56 PM
What is C46 (DNI ??) for? I did not see it in the picture...
QuoteI think that stands for Do not install
Correct, it stands for Do Not Install.
With this JFET bias, i found 1nF to give me a usable clock range of 9.5kHz - 80kHz. If you've ever worked with JFETs, you will find that the channel resistance (which is being used to modulate the clock) is not terribly consistent. You may need to slightly shift the clock frequency if your JFET happens to be different from the one i used, and having two capacitor footprints can get you strange values like 330pF + 470pF = 800pF.
Quote from: rustypinto on July 23, 2011, 11:28:56 PM
QuoteI never noticed you swapped the power arrangement... not a bad idea... I see you simplified a few parts aswell.
I recon with 2 x 3205s (instead of 4 x 208s) I might be able to shoe horn it into a 1590BB with onboard pots and no stand up resistors... running at 9V the bridge rectifier and regulator could happily be dropped and a zener used in its place to give the BBDs that slightly lower voltage they prefer (and allow for people to run the opamps at 12V should they prefer while protecting the BBDs) then as you say, just a case of swapping the pin arrangements and the compander resistors.
Cheers for the inspiration! 3205 Memory man here I come :icon_mrgreen:
One slight edit... to that, VGG should be 14/15 so to save on having a voltage reference i'd add a diode to each to drop VGG by 0.6V... close enough to 14/15th of 9Vs.
What about the outputs of the BBDs though... would they go to ground now instead or am I going insane.
I was never a fan of shunt regulators for analog delays, but it is certainly possible to save space. The problem is making the supply pins happy while dealing with the current requirements of the clock/CD4047, which changes over the full range of 100kHz-10kHz. The regulator method is more stable. Even if you use 12VDC on the op-amps, you can get away with a 78L09 powering the BBD's/clock, which is not terribly space constraining.
I tried to speak a little bit about VGG in my design notes. The datasheet specifies it to be 14/15V away from Vdd, but it still works if Vgg = Vdd. If you use the bias scheme i did, you can't get away with a simple diode or resistor drop because the voltage is in the wrong direction. You have to use a resistor divider to create ~1V with this scheme. I did breadboard it with both the resistor divider and where Vgg = Vdd, and i could not hear any difference at all. I remember reading an old BBD app note (Panasonic or Reticon?) that explained this pin in more detail, and mentioned that Vgg could be the same as Vdd for convenience (and it sure was convenient for the density of this layout), but said ideally it should be ~1V away from the supply.
(Moved our discussion from FSB over... no point in having a conversation across two forums :icon_mrgreen:)
I quite like shunt regulators not just for there small space but also because the 320X Series of BBDs seem to like a bit less than 9V so it's easier to get a Zener in 8v2 than a regulator... just a fairly neat and tidy simple solution.
Hmm... I think i'll risk it on the 4047, if it was a problem, hardly an issue to wire up a little daughter board 9V or 12V Regulator and the BBD is still going to be regulated by that 8V2 regardless... I guess you could even run it higher than 12V although i'm not sure how much good it'd do.
Ahh of course yeah... it would be a bit of a pain to magic up -0.6V but as i'm giving them positive voltage, should be all good... I doubt there is much different in it really but, good practice 'n' all for the cost of 2 diodes.
Quote from: rusty_pintoQuote from: Scruffie
One other question... not that I intend to do it right now but would using quads for the 8 Opamps in the audio section introduce any problems/hiss?
It will if its a LM324 :mrgreen:
I seriously doubt it though, but i've never tried it so i can't say for sure. I used SIPs because they lend themselves extremely well to dense designs. With this type of pedal in general, its the clock noise you have to worry about. You notice that i pushed the 4047 as far off to the corner as possible, and made sure to use shielded hook-up wire. I've done other delay designs where the clock just bleeds into the bypass or other parts of the signal path. You may not face this with board mounted pots, but then if you do, its much harder to fix it.
Yeah I don't think a quad would add noise either but thought it best to ask... SIPs i'm imagine do really help with this layout but if I can avoid ordering special parts, I will. The Quad idea was less about this layout anyway and actually leaning more towards a stripped down version of the Memory Man... perhaps using the Stereo Memory Man as a base which is already +V so adapting to the 3205 would be a breeze, dropping the stereo bit, and taking it back to just 4 OpAmps in the Audio Path then adding the LFO of the Deluxe Memory Man so it can do Chorus & Delay at the same time... possibly with 2 x 3205 I haven't decided on that.
Indeed, i'm very aware of clock noise... yeah board mounters do normally help a fair amount and on my current PCB layout (which i'm probably going to start again as I ended up leaving a huge chunk of unused board space which I could really do with!) it's up at the top corner with the BBDs and useing as short as possible clock pin tracks.
beautiful project!!!
I've only MN3005 now...can I substitute MN3008 with MN3005?
What should I modify?
Thanks!
I believe
2 x MN3008 = 1 x MN3005
Quote from: Govmnt_Lacky on August 02, 2011, 10:06:58 AM
I believe
2 x MN3008 = 1 x MN3005
Correct.
Quote from: karol3188 on August 02, 2011, 09:33:25 AM
beautiful project!!!
I've only MN3005 now...can I substitute MN3008 with MN3005?
What should I modify?
Thanks!
To use MN3005, the mod isn't really that clean, but it is possible. Note that if you stuff 4xMN3005's, the CD4047 will not be able to drive that much capacitive load at higher clock speeds (eg. ~20-100kHz).
To use 2xMN3005, place them at IC2 and IC3. Everything between C30 and C32 is not populated (including C30), and then everything between the output of IC8B up to R41 is not populated. Jumper R16/C17 to C32, and then jumper the output of IC8B to R25.
Quote from: rustypinto on August 02, 2011, 11:08:43 AM
Quote from: Govmnt_Lacky on August 02, 2011, 10:06:58 AM
I believe
2 x MN3008 = 1 x MN3005
Correct.
Pinto,
Can I assume that you used the MN3005s from Steve at Smallbear? The ones that are ACTUALLY 3008's ;D
Seeing as you have 4 of them in your lovely circuit above ;)
Quote from: Govmnt_Lacky on August 02, 2011, 12:37:38 PM
Quote from: rustypinto on August 02, 2011, 11:08:43 AM
Quote from: Govmnt_Lacky on August 02, 2011, 10:06:58 AM
I believe
2 x MN3008 = 1 x MN3005
Correct.
Pinto,
Can I assume that you used the MN3005s from Steve at Smallbear? The ones that are ACTUALLY 3008's ;D
Seeing as you have 4 of them in your lovely circuit above ;)
Yes, i used the same "2K fakes" that Steve is selling here (which is a great price IMO):
http://www.smallbearelec.com/Detail.bok?no=247
:D
very nice!!!!
we appreciate your hard work!
thanks for sharing!
ivan.
It says pair in Steve's description.
Are you getting two ICs for the 15.95 ?
Or is that because they are two ICs in one ?
(does it cost 32$ or 64$ to get all four IC's?)
Quote from: Brymus on August 06, 2011, 04:26:19 PM
It says pair in Steve's description.
Are you getting two ICs for the 15.95 ?
Or is that because they are two ICs in one ?
(does it cost 32$ or 64$ to get all four IC's?)
They way I read it... you get 2 of the IC fakes for $15.95
So you get all four for $32
(http://i999.photobucket.com/albums/af111/njkmonty/IMG_0575.jpg)
http://i999.photobucket.com/albums/af111/njkmonty/IMG_0575.jpg (http://i999.photobucket.com/albums/af111/njkmonty/IMG_0575.jpg)
Quote from: njkmonty on September 16, 2011, 08:07:23 AM
(http://file:///C:/Users/njkmonty/Desktop/IMG_0575.JPG)
You need to link the picture from a hosting site.
Try aron's, or dropbox, imageshack, etc.
i never new how to do it!!!!
was it url or img ???
because i did both?
Missed this one when it first came up. Very nice work indeed.
Take note, kids! SIPs are a wonderful thing and can make for delightfully compact footprints and easier layout. make sure you have some on hand, just to inspire your thinking.
Quote from: Mark Hammer on September 16, 2011, 08:35:35 AM
Take note, kids! SIPs are a wonderful thing and can make for delightfully compact footprints and easier layout. make sure you have some on hand, just to inspire your thinking.
???
http://www.andonelect.com/secure/ImagesClientUpload/sips%202.jpg
Quote from: njkmonty on September 16, 2011, 08:48:38 AM
http://www.andonelect.com/secure/ImagesClientUpload/sips%202.jpg
I know what those are however, I believe that Mark was referring to these:
http://cdn1.iofferphoto.com/img/item/198/883/142/S6eZ.jpg
SIP = Single Inline Packaging
My ??? comment was because I did not know how the comment related to this thread.
Quote from: njkmonty on September 16, 2011, 08:07:23 AM
(http://i999.photobucket.com/albums/af111/njkmonty/IMG_0575.jpg)
http://i999.photobucket.com/albums/af111/njkmonty/IMG_0575.jpg (http://i999.photobucket.com/albums/af111/njkmonty/IMG_0575.jpg)
Looks good!
Quote from: Govmnt_Lacky on September 16, 2011, 09:07:09 AM
My ??? comment was because I did not know how the comment related to this thread.
Because all the op-amps in the micro man are SIPs.
***A note to all ***
R18/R22 (which are specified as 33k/33k) seems to make this muddier than usual. The original DMM values were 24k/51k, which you can certainly use. These are meant to kill off a little bit of the signal coming out of the compressor and reduce the clipping (notorious in DMM's). You can also omit R22, and make R18 15k-16k to maintain the filter's corner frequency. This will result in a little less muddiness, and slightly more clipping. You can attempt to compensate this by introducing more attenuation with the inner stage BBD op-amps (IC6A/IC8B).
@njkmonty
That looks like a pretty good etch. Definitely go over it with an exacto knife as it looks like some of the traces are pretty close :icon_eek:
@ rustypinto
Thanks for the clarification. I should have been able to put that together!! :icon_redface:
Quote from: rustypinto on August 02, 2011, 12:43:07 PM
Pinto,
Can I assume that you used the MN3005s from Steve at Smallbear? The ones that are ACTUALLY 3008's ;D
Seeing as you have 4 of them in your lovely circuit above ;)
QuoteYes, i used the same "2K fakes" that Steve is selling here (which is a great price IMO):
http://www.smallbearelec.com/Detail.bok?no=247
I was kinda wondering why I say four MN3005s yet the graphics said 500msec. My first thought was "What the hell is he clocking those suckers at? And why doesn't he opt for more delay?"
Knowing that there is actually 8192 stages under the hood clears things up.
Don't sweat the SIP thing GL. With the markings on the side and not the top, folks don't necessarily recognize them immediately from their hairline! :icon_wink:
apart from opamps etc
what other components do you suggest i socket?
eg i noticed you mention r18, r22, i havent fully sat down and gone through everything,
but i usually like to high lite first the components which may need tweaking prior to install!
most parts im using are from smallbear , would like to avoid resoldering at a later date!
hers some more work in progress, any recommendations for extra component sockets for component tweaking?
(http://i999.photobucket.com/albums/af111/njkmonty/IMG_0579.jpg)
(http://i999.photobucket.com/albums/af111/njkmonty/IMG_0580.jpg)
(http://i999.photobucket.com/albums/af111/njkmonty/IMG_0578.jpg)
Quote from: njkmonty on September 17, 2011, 07:43:08 AM
any recommendations for extra component sockets for component tweaking?
i think what you have there is good. I didn't really anticipate sockets due to the density of the design, so i'm hoping some of the passive components will still fit with them installed. You'll just have to fiddle with them a bit, especially around the BBD sockets.
i socketed the inline ics, just in case i screwed up putting them in the wrong way or something!
socketed transistor aswell, and only the 2 x 33k resistors (r18 and r22)
i also realised its pretty tight when using boxed 1uf non electros too!! all 13 of them,
here is another progress pic, hopefully encourages other noobs!, apart from your biasing notes, i dont have an oscilloscope , so i might request a few tips before im done, !
:)
one, other thing, after ready back through my post i noticed it may appear that ive tried to blotch out young pedals info etc, this was totally unintentional, , that was a bad area in etch , so i coloured in with sharpie, since it was ground area!So non disrespect intened!!! ;)
also , only little things, but i used peel n press blue stuff, and i dont know why i didn't earlier, but this was my first transfer that it did on a pure flat surface,(was just doing it on the ironing board before!) ie flat chopping board. Its amazing how many obvious things get forgotten, unless someone spells them out!
(http://i999.photobucket.com/albums/af111/njkmonty/IMG_0588.jpg)
(http://i999.photobucket.com/albums/af111/njkmonty/IMG_0589.jpg)
ok, populated board
clean signal works
led works
15v coming through
correct power going to all ics
guitar signal coming through when effect on,
all pots appear to work
hear different effects/ squeal (light pitch coming through when adjusting pots)
tried different combinations of trim adjustments, but to not much avail
can this be biased/ tuned by ear? or close to it until i get a oscilloscope?
any suggestions?
(http://i999.photobucket.com/albums/af111/njkmonty/IMG_0591.jpg)
You can get it to work by ear. I found the first trimmer closest to the 3PDT is extremely sensitive and it took some very fine adjustment to get it working. For proper adjustment and fine tuning you really need an oscilloscope.
so the description of what Ive described, could be normal for a delay pedal which simply hasn't been calibrated?
Yes. Sounds exactly like mine before I calibrated it.
Im a "wandering in the dark" guitar fx dude!
i am willing to cough up for a rigol or equiv oscilloscope in the future.
couple of questions are....
1) even when i get one what then? shove some point probe somewhere and do something.?
i guess there is learning to use a basic one, but is anyone able to give some basic tips when the time comes to apply it to this???
(i know there are some pointers on the pdf) but even "inject a triangle wave???) this i hope doesnt require an electronics degree to work out?!
http://www.youtube.com/watch?v=fo7QQNdSIMQ (http://www.youtube.com/watch?v=fo7QQNdSIMQ)
The first step is tweaking the trimpots until you get delay. You'll need a signal generator to inject waves but you can use your pc and headphone jack to do this. Just google 'signal generator software'. But prove your cicuit works before heading down the scope path.
ok had a little more success, found some ic voltages from rusty_pinto at
fre-stom-bo-es.or-...
and found that mine where all close, so after looking at the schematic a bit i though i might be able to connect the output jack tip to pins 14 and 15 to here whats going on, yippee, i found a bit of a buzzing sound, and was able to adjust the trim pots quite easily to get an reasonable delay, remembering i wasn't getting any dry signal. Ok i thought
lets try the output of ne570, pins 10 and 11, and didnt get anything, am currently going over solders, and see if anyone has any suggestions???
Yes NE570/SA571 are the same part, but different manufacturer part naming convention.
I had posted voltages before, but it looks like some content was lost in the website server move. I'll re-post mine:
Supply = 12VAC
IC11 output = 15VDC
IC7, Compander, SA571 in my case (VDC):
Pin1 = 1.10
Pin2 = 1.78
Pin3 = 1.78
Pin4 = 0.00
Pin5 = 1.78
Pin6 = 1.78
Pin7 = 9.74
Pin8 = 1.78
Pin9 = 1.78
Pin10 = 2.98
Pin11 = 2.98
Pin12 = 1.78
Pin13 = 15.00
Pin14 = 1.78
Pin15 = 1.78
Pin16 = 1.07
IC1/2/3/4, BBDs (VDC):
Pin1 = 15
Pin2 = 7.25
Pin3* = 5.17 (IC1), 7.00 (IC2), 5.08 (IC3), 4.66 (IC4)
Pin4* = 5.16 (IC1), 6.97 (IC2), 5.07 (IC3), 4.64 (IC4)
Pin5 = 0.00
Pin6 = 7.22
Pin7* = 7.16 (IC1), 7.94 (IC2), 7.50 (IC3), 7.71 (IC4)
Pin8 = 0.00
*The input (pin 7) DC offset directly affects the output DC offset (pins 3/4). Again, these are MY bias settings, which were evaluated on a scope by setting the input offset such that the maximum signal passed through the BBD will result in symmetric clipping and distortion (top/ bottom). This will vary from BBD to BBD, but they will probably be close enough for you in most cases.
ok , after checking all bbd chips, and getting them all close to rustypinto 's voltages, i still got much of the same probs, so i decided to
see if any "delay only" signal was to be heard coming out of (after c8 (10uf) going into pins 14/15 of ne570, and woohoo!!
i could hear delay!!! this allowed me to easily rough tunes the trim pots to get rough ballparks to work with, but what i did notice,
was that pins 10 and 11 of ne570, where a little higher than rustypinto (about 3v his where in 2v's) so nothing was really coming out (i think?)
what is suppose to be coming out from pins 10 and 11?
i think i can see feedback pot connected after it
anyone make sense of my dribbles?
Im about to upload a quick youtube video to help explain what is happening in this build.
I've verified dry signal, and wet, all pots/switches seem to work, lfo etc
somewhere around the commander and last opamp something going amiss!
but i cant get wet and dry the same time as intended?!!!!! ??? ??? ??? ???
(http://i999.photobucket.com/albums/af111/njkmonty/ScreenHunter_01Sep211824.jpg)
also how do i connect a youtube videohere where you can play it in this forum?
ie not just a link?, the same way as a picture is displayed in our responses
Quote from: njkmonty on September 21, 2011, 04:42:29 AM
somewhere around the commander and last opamp something going amiss!
but i cant get wet and dry the same time as intended?!!!!! ??? ??? ??? ???
Looks like you've debugged it down to that area, but i know for certain that the blend works as intended (verified by a few others too).
Check that you've populated the parts in that area correctly, and use the "PCB Bottom Side 1:1" (page 4, bottom half) to compare your own PCB assembly to what was designed and verify that all the traces are present and making the proper connections. Check specifically for solder bridging and missing traces.
You are correct, the blend pot clearly works all pots and switches, do, what i mean is there is delayed (not super clean) going into
pins 14 &15 of controller.(This being my first analogue delay pedal attempt), seems to be correct. From pins 10& 11 of controller, im getting a slightly cleaner and quieter delay signal coming out and heading towards the final 1/2 of opamp ic12a 4558.Its on the other side of this opamp i get nothing pin 1!. Correct me please if im wrong , but is the ic12a section, there to clean up signal, and get it to correct unity to mix with dry signal at blend pot???
ive checked solder heaps but will do again, maybe add detailed voltages in that area to assist???
after all the debbugging, i still thought that i did everything, right, measured everything before putting in even capacitors!,
received a futurlec order today and tried the sa571n commander after pulling out the NE570 (i think i got from smallbear), and what do you know it worked straight away!!! woohoo!
which makes me wonder,..
why one chip worked and the other didnt, ??? a bad one? or something else?
any way will no doubt post further queries about fine tuning the calibration, anyone used dirk hendriks, probe circuit thingy????
one other thing. i was thinking of doing the flashing lfo led mod, would that be at the junction of pin 1 ic5a (4558) and r42 330r?
i got it flashing around in that area , just was wondering if there was a recommended place that wouldnt do anything negative to the sound?
Quote from: njkmonty on September 25, 2011, 10:42:56 PM
received a futurlec order today and tried the sa571n commander after pulling out the NE570 (i think i got from smallbear), and what do you know it worked straight away!!! woohoo!
which makes me wonder,..
why one chip worked and the other didnt, ??? a bad one? or something else?
one other thing. i was thinking of doing the flashing lfo led mod, would that be at the junction of pin 1 ic5a (4558) and r42 330r?
i got it flashing around in that area , just was wondering if there was a recommended place that wouldnt do anything negative to the sound?
Cool, i'm glad you found it. I have run into bad companders before too. I've been using On semi branded SA571 myself. Come to think of it, i did have an NE570 die on me before (don't remember where i got it though).
On the LFO LED: you can start at pin1, but it will probably change the bias on the JFET, which modulates the clock (IC9). Add it and play around with the modulation to see if its acceptable. You can also try pin 7 without changing the frequency too much. Ideally, you would want an op-amp buffer driving the LED since that would be unimposing.
have got the bug , with analogue delays, have just breadboard a aquapuss with 2 cool audio v3205s, nice.
i believe this build (Deluxe Micro Man) is all working correctly, but when i turn the "delay" pot from about 70% to full clock wise, that high pitch squeal kicks in.
with the dm2 clone the trim pot connected to the mn3101 can be adjusted to slightly reduce delay and completely remove squeal.
from what i gather this build has the trims to bias the bbd,s and 2 trims for gain on the 4558 ics. i believe Ive biased the bbd's very well without a scope, is there any other suggestions to remove this squeal?
here is breadboard aquapuss and micro man with squeal at long delays
Concerning the "squeal" (clock noise):
When i built mine, i used shielded, two-wire cable. You must attach the shield conductor to the PCB ONLY (the pad labeled "DLG" of the PCB assembly), not at the pot. I can't tell if thats what you did or not, thats just how i reduced most of my clock noise. I also noticed some reduction when the unit was put into the enclosure (not sure why).
yeah i did all the shielding etc correctly.
what i did try a few moments ago is swapping the smallbear 2n5457 with a different brand. this has reduced the squeal considerably , by about 50%, still present, though.
its funny that the breadboard delay has about same delay time, no shielding , (all over the place and id quiet as!)
(i guess prob due to the trim pot?)
does anyone know by the way what sort of pic i could use for breadboard delay to implement digital potentiometer for a tap tempo feature?
eventually boxed it up.
tried everything to get rid of squeal in the longer delay settings.
even replaced the last 2k4 resistors coming fromm bbd with a cancel 5k trim pot but no change. still sounds great would love to have it squeal free all the way, even cut traces going to and from footswitch and shielded them , no change!
from what ive read this is from the bbd chips? is it worth trying others? as ive read in some forums about some "real" ones displaying these symptoms. or should i not bother?
(http://i999.photobucket.com/albums/af111/njkmonty/IMG_0700.jpg)
(http://i999.photobucket.com/albums/af111/njkmonty/IMG_0701.jpg)
(http://i999.photobucket.com/albums/af111/njkmonty/IMG_0699.jpg)
I have made one used this schematic DeluxeMemoryManRevD.pdf,the sound is good but has some noise like the white noise .I donnt know why .this noise frequency is about 3000HZ