I have got a BOSS SE-70 with a BRB-230 12VAC adapter with similar click clock hum recently. Seems like it was a voltage filtering problem around +5V regulator and that caused some bugs in a digital supply, so that hum varied with a preset type due to a dsp/cpu load higher or lower. The problem was f...

Mr.Disco, I live in Russia, Saint-Petersberg and can provide you with a good stable serviced unit and if needed can do few kinda usefull mods to it like increasing lfo range, 2vocice portamento and midi support.
just PM me and we can discuss details.

basically it is not midi equipped but it has control input for controlling the synth from other ems-1 synth keyboard which can be quite easily moded for use with a cv/gate devices wich support volt/herts rate. but that's only for synth section, poly organ section can be midified only with a hard mod...

thanks! keys have such colour because of shitty plastic material them are made of. with time it just becomes damn yellow and no chances to clear it back.. many soviet synth keyboards suffer from it, although not all.

This one is the most powerfull Soviet synth instrument made in USSR from my point of view. Upper section is a 2 Osc monophonic synthesizer with lot's of control, Polivoks type VCF and ringmod. Low manual is a 6 preset organ/strings section with a little control, just good as is, despite very wierd n...

Oh maybe..
it's kinda bug on mpc60 when it triggers the same sample twice in simult mode, actually it plays it 2 times with a tiny delay and it even slightly vary this delay from hit to hit. I just found this effect funny.

Greets to all VSE People! Here I want to show my first track made with only vintage instruments I own. http://soundcloud.com/volodja/logich-feat-den-davydov Bass and pad sounds are from Roland Juno-106. Strings and vibes from Roland U220. Synth sound from soviet Ritm-2 synthesizer, it's a pity that ...

500-700S for an hour of work is a little bit much I think 8-) I have made my midi kit for polivoks, here is a brief demo http://www.youtube.com/watch?v=F6PTIRia0Ys it supports midi in (4oct), midi through, vcf cutoff modulation by cc01, pitchbend and velocity and has some perfboard space for additio...

sam wrote:

deeplodok wrote: I am hoping the power supply is the solution...After 3 years I can hear what it sounds like.

sounds really sicK
but is unpredictable if wasn't serviced properly yet, for good and stable operation will need also to be tuned and adjusted with good accuracy which is not that simple.

BD139 is direct pin2pin replacement for V2 КТ815Г,
for V3 any general purpose npn transistor like 2n3904 or other will fit good here, but be carefull with correct EBC pin placement.

ua740 seems to be good replacement for 140уд8б

positive rail stabilisation circuit seems to be broken, +20V is a voltage directly after rectifier, first of all check A1, V2, V3, V1(7V Zener Diode) http://imglink.ru/pictures/08-07-11/f4e46447e384f847b8eed3e0eafe2c74.jpg in the bottom of the picture is a table with the control potentials that may ...

not at all, just give it a try

no problem, all can be done from the inside. remove the modules from the board, disconnect the wires and then uscrew the desired half of the main pcb, all pots are fastened on it. the plastic surface is not disasseblable as i can remember.. anyway, there is no problem to find a pot that would sit go...

hey, there is no reason to remove a plastic surface to change a pot, you just need to unscrew and disconnect mother-pcb with regulators from the inner side, and then things get easy.