Vintage Synth Repair

It's unlikely that any parts are just going to quit working overnight,
so start with the obvious: make sure everything is turned on properly,
then make sure your connections to all of your equipment are solid and
not flaky.

Open up the Initial Gain slider and see if that changes the volume at all.

If not, then it might be the VCA that's at fault. If it does make some
change (any change), then it might be upstream at the filter.

Get the service manual here (www.arpodyssey.com) and try listening to
the output at the suggested Test Points listed on pages 19-24.  Start
at the VCOs and work south.

Might be dirt in a slider, might be corroded connector strips, might
be no trigger or gate from the keyboard, might be a bad transistor in
the envelope generator(s).  Or something else.

Good luck.

--- In vintagesynthrepair@yahoogroups.com, "nau.dylan" <dylannau@...>
wrote:
>
> Hey there List!
> Suddenly my Odyssey MKIII is not working properly. I can hear the
normal hiss from the unit 
> at normal volume and when I press the keys I can hear that normal
low end clicking sound 
> but the tones out of the oscillators and noise generator are
practically gone.  I can still hear 
> the oscillators working at a very very very low volume.  I move all
the sliders and try 
> everything but still not working like it was.  Since I got the thing
I have replaced 
> the key bushings and put some deoxit lube in the sliders.  The night
before I was running a 
> bass guitar through the audio input and messing with the sounds of
that (not that cool 
> sounding) with the filter.  I powered off the unit, then the next
day powered it up and have 
> this problem.  I opened it up and everything seems to look fine on
the PCB board but I am 
> not an expert.  Any thoughts?
> Thanks much,
> Dylan Nau
>