EM3207 (v1.1) - MN3207 based EHX Electric Mistress (9V) clone

[Thomeeque]

P.S. I hope, Thomas will not object to ...  

I'm learning a lot from your posts, please go ahead I just reserve right to disagree time to time T.

[Keeb]

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.

[Thomeeque]

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.

[Keeb]

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.

[Thomeeque]

speed does nothing...

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

[Keeb]

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

[Ummagumma]

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

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

Thanks Thomeeque and all of you guys! 

[Thomeeque]

 

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.

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



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!  

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

Cheers, T.

[Keeb]

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:

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.

[GodSaveMetal]

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: :
My etching PCB (Iron method):

The face markers for the components in its side:

All the jumpers in the components side (there are too long):

The jumpers in the solder side (um mm perhaps a short circuit in it!):


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):


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:


And all the rest put together; I use a individual PCB for the pots:



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

I'm making the EH3007 version; I'm here with it; a new mask and a new PCB pots: 


The jumpers are more shorter all in the components side:


All the caps in the components side:


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!!! 

[Thomeeque]

 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?

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) - 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)

[GodSaveMetal]

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:


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!

[Keeb]

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:


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!

Have you checked your voltages?
If you look a  while back I got some serious help...

[oldschoolanalog]

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!
You may now return to your regularly scheduled program...

[GodSaveMetal]

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! but the MN3007 all i proved that are god in the MISTRESS I made! OK thanks man !

[quarara]

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!
You may now return to your regularly scheduled program...

+1

[Thomeeque]

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!
You may now return to your regularly scheduled program...

+1 Thanks Dave (and Luigi)! T.

[njkmonty]

Hope I can ask a question without a big "public service announcement" hammered after it!
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.

[oldschoolanalog]

Both.  
Can never have enough Mistresses...

[12Bass]

Hope I can ask a question without a big "public service announcement" hammered after it!
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.