Some "information" on the CL-1 diode that I found here:
http://electro-music.com/forum/viewtopic.php?highlight=901&t=46468
Probably a generic (silicon) rectifier would be fine as the author says (not a germanium 1N34)
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Node "A" on the base of Q7 goes to "A" on the connector
I'm guesting that "TPA" is "Test Point A" on a transistor matching schematic in a 901 service manual (like in the Minimoog SM, but that one is measuring Vbe for match.) The note is referring to Q8 and Q9.
Good luck,
Tom
--- On Sat, 2/19/11, Scott <painintheamp@...> wrote:
From: Scott <painintheamp@...>
Subject: [vintagesynthrepair] Re: Moog 901B
oscillator
To: vintagesynthrepair@yahoogroups.com
Date: Saturday, February 19, 2011, 8:49 AM
--- In vintagesynthrepair@yahoogroups.com, "André Hartung" <a.hartung@...> wrote:
>
> You mean 11.98 volts.
>
> Sent from my Nokia mobile
> -----Ursprüngl. Nachr.-----
> Von: Scott
> Gesendet: 18.02.2011 13:41:39
> Betreff: [vintagesynthrepair] Re: Moog 901B oscillator
>
>
> --- In vintagesynthrepair@yahoogroups.com, "Quazimodo" <noddyspuncture@> wrote:
> >
> > Of course -stupid me... now I see it. Thanks for all the replies guys.
> >
> > A couple of other things confusing me on this schematic - where it says "selected for 2.45v at TPA..." - are those refering to Q8 and Q9...? And would TPA be the "A" on the base of Q7. Also Q7 says "selected" but with no explanation!
> >
> > Finally, what diode could be used for D2 CL-1 ... could that be a IN34 ... ?
> >
> > Cheers,
> > TOM
> >
> >
> >
> > --- In vintagesynthrepair@yahoogroups.com, no freq <no.freq@> wrote:
> > >
> > > Look, +11,5V is made out of the +12V and comes from the node formed with
> > > R1, P2 and C1, directly on the board. You'll find it in the upper left part
> > > of the schematic.
> > >
> > > Le 17 févr. 2011 21:57, "Quazimodo" <noddyspuncture@> a écrit :
> > >
> > >
> > >
> > > Hi guys,
> > >
> > > I have a question about the Moog 901B Osc.
> > >
> > > Looking at the schematic here:
> > >
> > > http://www.freeinfosociety.com/media/images/4142.jpg
> > >
> > > I see the +12v, -10v and -6v points noted - but I am also seeing three
> > > points marked +11.5v
> > >
> > > Where was this +11.5 derived from originally?
> > >
> > > If you look at the connector strip pin-out on the bottom right - there is no
> > > +11.5v coming in..!
> > >
> > > Cheers,
> > > TOM
> > >
> >From electronic theory , there's 1.2 mA flowing thru R1 and P2
> That means there's 10.98 volts at the junction of R1 an P2.
>
> Either the 11.5 is a nominal voltage or they have the wrong value for R1 to get 11.5 volts there. I think it's only used to partially isolate the "11.5" from the reg +12 volts
>
>
>
Yeah...11.98 volts...I have coffee nowMessage
Re: [vintagesynthrepair] Re: Moog 901B oscillator
2011-02-20 by Tom Russell