This is a 90s Deluxe Electric Mistress reissue (EC 1000 Rev B) that I was asked to look at. It passed a clean signal, but no effect. You could sort of hear something happening when power was cut to the pedal but it was very weak. This seemed like a positive, it meant the BBD was still able to do something.
Going through this pedal was pretty easy thanks to Ralf Metzger's fantastic Electric Mistress site (presumably inspired by Kit Rae's Big Muff shrine). Ralf has info on identifying different versions & reissues, theory of operation, full schematic and repair & aligning instructions. This version (V4) has a Reticon RD5106A BBD and 24V DC input. Oddly enough there is no bypass indicator LED, this is usually a good way to tell old EH pedals from the reissues.
Walking through the alignment procedure for the V4 I found that I couldn't adjust the clock signal to get as low as the specified 40 kHz. I had some clock signals at the BBD but I couldn't see any modulation on them in any switch or knob settings (the modulation of BBD delay time produces the flanging effect). After buzzing out the circuit it turned out that there was no continuity across any of the terminals of the Filter Matrix switch. As far as I can tell the switch wafer was removed or disappeared somewhere, sliding the switch didn't bring anything in contact with the terminals. I wired in a spare DPDT switch in parallel and had a working flanger.
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| Temporary eplacement switch added across the original. |
I did a quick alignment following Ralf's guide to correct any adjustments I made when it was working incorrectly. The only diversion was setting feedback, I always feel that any pedal with a feedback control should be just about oscillating at the extreme end. It will get a replacement slide switch, they are easy to source but I didn't have one at hand. The switch doesn't effect calibration so it can be swapped out later.
This is the first through-hole pedal I've written up here. I suppose not having any SMD parts makes it the least false.
Cheers to Ralf.
Hey krivx, just bought a used DEM (V5) and am pretty sure mine is having the same issue as this. Would you be willing to give it a repair?
ReplyDeleteIf you can, you can contact me further @ elliotscottthomas@gmail.com
Hi Elliot. Usually when someone asks about a repair the answer is "probably no". If you are geographically close to me and not in any kind of a hurry to get your pedal back then it's possible, but usually I find it hard to devote time to doing repairs for customers unless they are very quick jobs.
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