>then maybe they should be replaced with tl084.
>From: "selfoscillate" <synaptic_music@yahoo.com>
>Reply-To: Doepfer_a100@yahoogroups.com
>To: Doepfer_a100@yahoogroups.com
>Subject: [Doepfer_a100] Re: A-126 VCFS (Frequency Shifter) Problem
>Date: Sat, 12 Nov 2005 12:45:46 -0000
>
>
>hello,
>
>i checked the service manual of the a126 and i think
>that i found the possible reasons for the malfunction,
>but these should only occour with the first two
>production series of the a126. a freshly
>purchased a126 shouldn't have these problems
>and should be returned for service in that case.
>
>this is a rough translation from german to english,
>i apologize for possible errors. if somebody is
>interested, i can post the full text in german.
>i guess this is ok, dieter?
>
>1. check the ic5 and ic9 on the pcb. if these are tl064,
>then maybe they should be replaced with tl084.
>
>2. the sine/cosine vco is built around a cem3382,
>which works correctly in a range of 50 - 5000 hz.
>however, if you turn the freq knob fully cw and
>apply a control voltage, you may go beyond these
>limits and the cem3382 stops oscillating.
>this happens when the voltage applied to the cem3382 ic
>exceeds +6 volts. to prevent this, a 5.6 volts zener diode
>has to be inserted between ground and the voltage inputs
>of the cem3382 (the anode to ground).
>
>3. when the a126 is modulated with a square wave at
>audio frequencies, then under rare circumstances the
>cem3382 stops oscillating too. this can be prevented
>by adding a 1nf capacitor between r51 and p12.
>
>hope this helps clearing up the issue.
>
>best wishes
>
>ingo
>
>
>
>--- In Doepfer_a100@yahoogroups.com, "Tim Stinchcombe"
><timothy@t...> wrote:
> >
> > I'm not aware of any problem like this with mine, but from memory,
> > the amplitude of the internal oscillator takes a while to settle
>down
> > after a CV change, and so (I'm guessing here) maybe at high CV it
>is
> > possible that it might stop running completely. I'll check it out
> > later today and report back then...
> >
> > Tim
> >
> > > same problem with mine,
> > > anyone got a solution to it..?
> > >
> > > /daniel
> > >
> > >
> > >
> > >
> > > --- In Doepfer_a100@yahoogroups.com, "Tommy DOG" <mrsvomit@t...>
> > wrote:
> > > >
> > > > Then mine does too.
> > > > It's always behaved like that.
> > > >
> > > > TD
> > > >
> > > > --- In Doepfer_a100@yahoogroups.com, Bakis Sirros
> > <synth_freak_2000@y...>
> > > wrote:
> > > > >
> > > > > hello zoran,
> > > > > it seems to me that your a126 vcfs needs repair.
> > > > > bakis.
> > > > >
> > > > >
> > > > >
> > > > >
> > > > >
> > > > > --- Zoran Bosnjak <dj_allin@h...> wrote:
> > > > >
> > > > > >
> > > > > > Hello,
> > > > > >
> > > > > > I purchased A-126 VCFS (Frequency Shifter) recently,
> > > > > > and I noticed that when
> > > > > > rotating Shift knob towards value 10, and applying
> > > > > > control voltage to CV1,
> > > > > > the module stops functioning. I have to turn the
> > > > > > whole case off and on, to
> > > > > > reset it and have it work again.
> > > > > >
> > > > > > Is this behaviour by design or my unit is faulty ?
> > > > > >
> > > > > > Regards,
> > > > > >
> > > > > > Zoran
> > > > > >
> > > > > >
> > > > > >
> > > > >
> > > > >
> > > > > Bakis Sirros
> > > > > Parallel Worlds
> > > > > Athens-Greece
> > > > > [Doepfer_a100] group owner
> > > > > http://www.shimarecords.co.uk
> > > > > http://www.rubber.gr
> > > > >
> > > > >
> > > > >
> > > > > __________________________________
> > > > > Yahoo! FareChase: Search multiple travel sites in one click.
> > > > > http://farechase.yahoo.com
> > > > >
> > > >
> > >
> >
>
>
>
>