Vintage Synth Repair

Well said. That was indeed one of these transistors !

Any known substitutes for these ?



--- In vintagesynthrepair@yahoogroups.com, "thirteentech"
<thirteentech@...> wrote:
>
> Look for a leaky transistor in the chorus circuit. The general
purpose NPN and PNP 
> transistors that Roland used in so many machines seem to fail quite
often. They begin to 
> leak and cause pops. I come across them with leakage problems in
TR909's all the time, in 
> JP6 power supplies, and Juno 106's. They are 2SA115's and 2SC2603's.
From memory 
> these are used on the Juno chorus/output board as well.
> 
> 
> --- In vintagesynthrepair@yahoogroups.com, "Scott" <painintheamp@>
wrote:
> >
> > --- In vintagesynthrepair@yahoogroups.com, "Dorus Manassis"
> > <thorosm@> wrote:
> > >
> > > --- In vintagesynthrepair@yahoogroups.com, "gil_we" <gil_we@> wrote:
> > > >
> > > > Is there any particular component on the Juno 106
amplification/chorus
> > > > circuit that could cause one side to make a "tick" noise with
every
> > > > LFO loop ? 
> > > > 
> > > > It may sound louder on one side compared to the other, if that
> > helps...
> > > > Replaced the BBD's but no change. Thanks !
> > > >
> > > 
> > > i think i have the same problem with my MKS-50....
> > > 
> > > i would be interested to know too....
> > >
> > Does that part of the circuit have a potentiometer?
> > Most discrete chorus circuits Ive seen have a pot that needs to find
> > the "sweet spot" where the oscillator works but doesnt overwork
> >
>