This is the third Quasimidi Polymorph I have rebuilt in the past six months, and the second that I have done for out-of-state clients who contacted me after searching for “quasimidi polymorph repair” (see what I did there?) and coming across my first post about it. The Polymorph is not a vintage synth nor a very common synth, but it is a very powerful and unique synth that is much beloved by its owners, and at around 15 years old at this point, pretty much every Polymorph out there now suffers from a debilitating knob jitter issue. Continue reading “Quasimidi Polymorph (#3) – our Polymorph repair and rebuild service”
11/3/2019: OK, I have yet another update on this!
Unfortunately, about 2 years after I implemented the fix I describe below (debouncing capacitors for each pot, plus a shield) the issue came back!
I wanted to take a closer look through the circuitry with my oscilloscope but did not yet get a chance to because when I opened it up, the issue went away. So I just did my best guess of what might help and packed it up yet again.
I had a good idea of what might help, because thinking more about the symptoms had led me to a stronger idea of what might actually be the issue.
There are really two symptoms:
1. constant random jittering of pot values, which is what people usually focus on
2. the pots can NOT be turned down to 0, the minimum value anything can reach at full counterclockwise position is 2 or 3 for me usually. Continue reading “Korg Electribe ESX-1, continued / updated Nov. 2019”
UPDATE 8/28: As it turned out, the work described below did not fix the problem with the Electribe. If you are having a problem with jittery knobs and value jumping of your Electribe’s controls, please refer to my later post on the topic for the actual solution!
Just as they say “the cobbler’s children have no shoes,” so also do they say “the synth tech’s gear has 14 jittery knobs and isn’t even screwed together.” I decided to “treat myself” to a couple hours spent working on one of my own instruments yesterday and as a result I probably now have the best-working Korg Electribe ESX-1 in the universe. Continue reading “Korg Electribe ESX-1”
The unapologetically boring-looking Quasimidi Polymorph is a very powerful VA polysynth from the early 2000s that allows you to sequence and play back 4 parts on 4 different synth sounds, recording and playing back all the parameter edits you make along the way, and send them out on 4 individual outputs. So basically it is 4 sequencing polysynths in one. Continue reading “Quasimidi Polymorph – knob jitter hell”