Vintage Synth Repair

neither are "noise". the "pink" noise is just a slightly different
tone of the weird waveform i mentioned before. i messed around a
little bit "circuit bending" it with another transistor pluggined in
at the same time and got something closer to white noise but still
with a strange pitch.

is there a way i can find an older transistor or a better match? i'm
using a transistor labeled "2n 5172" with an F icon on it, so i'm
guessing it's a fairchild brand? something like that. i know i am
replacing a "sel 2n 5172"... maybe these two are too different?

-johnny

--- In vintagesynthrepair@yahoogroups.com, "balderson04"
<djacklin@...> wrote:
>
> Hi, Johnny:
> 
> The service manual's description of the noise circuit mentions that Q9
> is specially chosen "for optimum avalanche characteristics", so it may
> be that the transistor you've installed is not breaking up in the same
> way.
> 
> Try listening to the noise output at pin 6 of A3 and comparing it to
> the output at pin 6 of A4.  The first should be white noise and the
> second pink noise.
>