Vintage Synth Repair

--- In vintagesynthrepair@yahoogroups.com, "Roy J. Tellason"
<rtellason@...> wrote:
>
> On Saturday 04 February 2006 12:14 am, P........ wrote:
> > Well hello, everyone! I have recently purchased a Arp Omni 1, but from
> > the first moment on I kept having trouble with one note stuck at E in
> > the first octave. Let me explain the symtomes: when switched to
> > bass(synth) I'm able to play the notes from C1 to E1 then every other
> > key I press after that makes the same sound. When switched to full
> > strings/brass no matter which or how many keys I press or how I set
> > the attack/sustain envelopes I always keep hearing E1 playing along
> > with a long sustain. Did anybody else encounter this problem and how
> > can I get that fixed? Help, please??
> 
> You're getting one note that just wants to bleed through the whole
time?  I've 
> hit that one before,  a few times...
> 
> ARP screwed up on the choice of one particular component in there,  the 
> 22uF/25V Tantalum caps they use to sustain a note.  That particular
circuit 
> has,  with extreme settings of the sustain slider,  up to 30V across
those 
> caps at times.  I guess it speaks well for the quality of the parts
that more 
> of them don't blow up,  tantalum caps have a way of doing that,  rather 
> spectacularly at times.
> 
> You'll need to find out which cap it is (there are rows of them)
that pertains 
> to the particular note that's bleeding through -- easy enough, 
it'll be the 
> one note that plays cleanly without any _other_ note coming through.
 Clip 
> out that capacitor and the bleedthrough will be gone,  except of
course that 
> the note now won't sustain until you put a new cap in there.  Get a
35V unit 
> to replace it with,  and you should be okay.
> 
> -- 
> Member of the toughest, meanest, deadliest, most unrelenting -- and
> ablest -- form of life in this section of space,  a critter that can
> be killed but can't be tamed.  --Robert A. Heinlein, "The Puppet
Masters"
> -
> Information is more dangerous than cannon to a society ruled by
lies. --James 
> M Dakin
>

Thanks alot! Well I took the synth apart and.. this might sound silly
but I'm really not that technically gifted although I do have some
soldering skills and as you propably found out through my not so good
grammar I don't originate from this country so I'm wondering if when
you talk about caps do you mean the blue capacitors which I see
together with rows of resistors at the bottom part of the lower
voicing section and should I do the same thing in the upper voicing
section too? And would that also fix the problem with the bass
section? I also could need some schematics and info to see which cap
refers to which key so that I don't cut the wrong one.