Vintage Synth Repair

Hi,
I have replaced caps on the Omni 2 and it had electrolytics in it.
Also the Quadra has electrolytics as well.
Each time I have replaced them the new caps are smaller (cap 
evolution).
But they are rated at 35v.

You can also get them at 50v and they are still smaller than 
the originals.

Just my 2 cents.
Thanks.
GD



> 
> The negative end of the cap sits at -15V.
> 
> I hate to admit that I somehow messed up my measurements (or 
actually: I
> did them at the wrong place; I measured them at the sustain buss 
but should
> have done them directly at the caps). The voltages seen by the 
caps are
> actually a bit lower.
> 
> Everything I wrote before is basically correct, with one 
exception: The
> sustain buss and supression trigger have to pass a 3.3k resistor, 
a diode
> and another 470R resistor before the cap.
> This results directly at the caps in 7.x volts for short release 
and 0
> volts for long release (the sustain buss is indeed at +8/-15 
instead). This
> also means that the spike from the supression trigger is not at 
+15V but at
> around +8 or +9V (definitely under 10V) for the shortest release 
time.
> Which in turn means that the max voltage difference is indeed 
around 23 to
> 24V at the cap. Which is uncomfortably close to the rating of 25V 
but
> within it.
> Is this good engineering? Probably not.
> 
> -- 
> Malte Rogacki gacki@...
> -------------------------------------------------------------------
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> "Don't forget to TURN ON THE SYNTHESIZER. Often this is the reason 
why you
>  get no sound out of it." (ARP 2600 Owner's Manual)
> -------------------------------------------------------------------
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>