Vintage Synth Repair

----- Original Message -----

From: Quazimodo

To: vintagesynthrepair@yahoogroups.com

Sent: Friday, June 29, 2012 4:51 PM

Subject: [vintagesynthrepair] Re: Minimoog D pitch drifting

So it's a late, *stable* one... OK, then it will probably be much like I said in the first place.

Check those flags...!

--- In vintagesynthrepair@yahoogroups.com, "Gil" wrote:
>
>
> Thanks. Serial is 12044. Supposed to get it in a few days so I'll be able to tell what it exactly uses (or do you know be the serial number?)
>
>
> --- In vintagesynthrepair@yahoogroups.com, "Paulo Palmieri" <paulopalmieri@> wrote:
> >
> > Hi Gil,
> >
> > Probably there is a variation in the cv voltage that controls the oscillators.
> > I experienced similar issues on the osc 1 of a RA Moog model (the first earlier version) and the only thing that solved the problem was replacing the 2n4058 transistors.
> > Please, provide more info such like serial number and if your oscillator board has only transistors or 2 ICS SG3821 or CA/LM3046 or 3 UA726 ICs.
> >
> > Regards,
> >
> > Paulo Palmieri
> >
> >
> > ----- Original Message -----
> > From: Gil
> > To: vintagesynthrepair@yahoogroups.com
> > Sent: Thursday, June 28, 2012 9:55 AM
> > Subject: [vintagesynthrepair] Minimoog D pitch drifting
> >
> >
> >
> > I'm handling a friend's mini, which acts strangely. The overall pitch (of the entire machine) will change suddenly, up and down, not to far from the correct pitch but a few semitones... It affects all oscillators at the same time. Is this a known issue in old minimoogs? I would usually suspect either power supply main voltage instability, bad caps or transistors, but being it affecting all 3 oscillators, I tend to think it is not oscillator circuit related ? :/ I'm new to minimoogs so any help would be appreciated... Thanks !
> >
>