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

[Amitay3333]

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.

[Ben N]

אחלה! זה המקום, אחי, כאן תמצא את המומחים.

[Thomeeque]

You can try to check EM3007 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.

[Mark Hammer]

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.

[Mark Hammer]

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.

[jyka]

Hello

Is thit possible to cancel the switch to keep the flange position ?

Jyka

[MisterMocha]

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:




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