9V Electric Mistress retrofit with MN3007

[Scruffie]

Right... I finished my Electric Mistress today and played about with it, everything is working as it should and sounding great except I have a dead spot at the very top of the sweep, i'm sure i've read about this problem before but I can't remember the cause...

Granted I haven't played with the clock arrangements too much so I guess it could be that? It's definitley there though, I tried the pedal with a distortion in front and I could clearly hear the sweep stop while the distortion played through.

Any ideas?

[Fender3D]

...I have a dead spot at the very top of the sweep, i'm sure i've read about this problem before but I can't remember the cause...
...
Any ideas?

Try lowering the highest clock frequency, maybe you've reached the point where MN can't work properly.
"Clock buffering" came after this after all.
It might be a layout issue (clock tracks too much long, or running too much near other tracks, thus suffering capacitive effect) though, not just a chip issue.

[Thomeeque]

Try lowering the highest clock frequency, maybe you've reached the point where MN can't work properly.

I my case it was always already the clock generator (311+4013) itself causing clock drop-outs (IIRC 311 was still ticking, but 4013 was not processing signal properly from some point and outputs were frozen, probably due to cripled shape of the signal at 311 output).. Highest frequency at 4013 outputs I've got was around 1.2MHz..

Scruffie, what exact diode do you have in the clock generator (between pins 3 and 7 of LM311)?

T.

[Scruffie]

Try lowering the highest clock frequency, maybe you've reached the point where MN can't work properly.

I my case it was always already the clock generator (311+4013) itself causing clock drop-outs (IIRC 311 was still ticking, but 4013 was not processing signal properly from some point and outputs were frozen, probably due to cripled shape of the signal at 311 output).. Highest frequency at 4013 outputs I've got was around 1.2MHz..

Scruffie, what exact diode do you have in the clock generator (between pins 3 and 7 of LM311)?

T.

Must just be the clock setting, as I said, I just got it flanging and left it, so i'm sure some tweaking will sort it out.

And I used a 1N4148.

[Scruffie]

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?

In the first case you may be interested in my EM3207 project. It looks like this at this moment:

Hey Thomeeque, what ever happened with this layout? I'm thinking another 3207 Electric Mistress with the TZF Mod in a 1590BB Could be nice...

[Govmnt_Lacky]

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?

In the first case you may be interested in my EM3207 project. It looks like this at this moment:

Hey Thomeeque, what ever happened with this layout? I'm thinking another 3207 Electric Mistress with the TZF Mod in a 1590BB Could be nice...

+1 

Is there a sound clip of this in action? Are you going to share the layout? I am interested in an MN3207-based flanger.

[GodSaveMetal]

yeah I'm too interesting in that layout and PCB also!!! please would you post that!!!!

[Thomeeque]

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

Roberto, Govmnt_Lacky, Scruffie - thanks for nudge T.

[Satchmoedie]

I know I built a Paiaa or what ever they are OLD flanger kit from just the schematic. It called for the 1024, but at the time NTE had a 1024 type chip. Most of the things that were not on their version were internally connected and the schematic had them externally connected the same way, so I eliminated some of the pins connections and it worked fine using a VCO and compander and some other things for clocking and not the usual suspect chip(s). It worked fine. I like the buffer in this design. I have too tight a budget to pay $60 for an SAD 1024 right now.  The MN series has worked well for me. I am crying about 1024 prices and dropped $10 on a 5000 chip that is analog computer delay line, and have no clue if it will work or not.     Try NTE's older books from the 1970s-80s. They made a 512 chip that some small shops still may have. It can be used much like the SAD 1024 and is the same thing as far as I can tell as it is a 512x2 chip. The pin out sure looks a lot alike to me, but I are not too smart~!

[antoniocnn]

Sorry. I have a problem.
Why do 9V Electric Mistress retrofit with MN3007 burn 10R resistor?

[Thomeeque]

Sorry. I have a problem.
Why do 9V Electric Mistress retrofit with MN3007 burn 10R resistor?

• Faulty IC2 (shorting VCC to GND)
• Faulty C4 (shorting VCC to GND)
• Solder (or PCB trace) bridge between C4 pins

[JRM]

Hi guys, I'm building the MN3207 retrofit with the layout designed by jorger. This is just to point out that the layout has a bug: the 22uF capacitor that is right next send/return holes has been moved in the silkscreen layout but NOT in the ready to transfer layout on the 2nd page of the pdf. So, if you don't need the TFZ S/R you can use that pads to place the 22uF capacitor but if you do you'll need to tweek it a little bit and solder the Send wire to one lug of the capacitor. I can't wait to finish it! Maybe tonight...

[JRM]

Just finished it and I have dry signal but no flanging
Have to check everything... again...

[pinkjimiphoton]

hey guys, could someone please re-up the schematic for using an mn3007 for a sad1024?

i wanna fix my bud's old mxr echo, but don't wanna hassle with trying to find a sad1024 when i gotta bag of mn3007's

thank you!

[JRM]

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/

I have checked layout picture and I'd say it's OK (good work with the graphic editor btw.!), just two small notes:

- make somehow visible on the layout and the PCB, that it's not EM RF V0.1 to avoid further confusion with original MN3007 version (maybe just add N as N-channel to version number like V0.1N)
- I have used same circuitry in my EM3207 and as I say above, I'm not 100% satisfied with the result yet - but you may be, it's really just a note

Good luck!

T.

It's here. Mine is FLANGING it was just a bridge to ground on the MN3207 circuit. Still got to tune the trim pots properly.

[trat rödenback]

Hello,
I built the EM with the 3007 and it flanges happily. BUT it is very noisy. I have a lot of flanging going on even if the guitar isn't plugged in or if i'm not playing. Is this due to a faulty OP-Amp? Or maybe the gainboost at the end. I tried a fresh battery and a wallwart - both sound the same except the wallwart introduced some hum. I did an audio probe and the output of the mn3007 is not noisy but seems to have a tiny portion of the clock signal.... maybe i gave up too soon? If nothing helps i'd give the EM3207 a shot (although with the 3007).
Any help apreciated.



sorry for the quality. didnt have a camera so i scanned it.

[trat rödenback]

oh, and I modified the layout a bit so i could squeeze it in a hammond 515-0910.
would it help if I posted audio examples?

[trat rödenback]

here's a recording through a fender blues junior. the longer the delay time the more noise i get...
http://dl.tonfang.de/NoisyEM.mp3

[pinkjimiphoton]

longer delay always introduces more noise in analog bbd's i think.

[Scruffie]

longer delay always introduces more noise in analog bbd's i think.

This is true.

If anything is wrong (can't listen to the clip at the moment to tell) i'd put my money on you either have a wrong value, too much feedback or a cold joint is stopping some LPF working.