My Frequency Shifter has four TL064CN's and one TL084CN. That single TL084
is at the bottom, close to DOEPFER sign in the corner. Is this how it is
supposed to be

Regards,

Zoran

1. check the ic5 and ic9 on the pcb. if these are tl064,

>then maybe they should be replaced with tl084.


>From: "selfoscillate" < synaptic_music@... >
>Reply-To: Doepfer_a100@yahoogroups.com
>To: Doepfer_a100@yahoogroups.com
>Subject: 1 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
> > > > > 1 group owner
> > > > > http://www.shimarecords.co.uk
> > > > > http://www.rubber.gr
> > > > >
> > > > >
> > > > >
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>
>
>