Doepfer

> I've had a Quantizer from new, and I've just had a 2nd hand one
> repaired by Doepfer, themselves.  Why are they both completely
> out of whack?
>
>   Neither tracks 1V/Oct (I played it in concert with my Midi
> keyboard) and the Voltages jump at different times.  They are
> also out of tune with each other.  This happens using a buffer or
> when driving a single VCO.  This renders them unusable.
>
>   Can I do anything to fix them?

You find the adjustment procedure on our website:

www.doepfer.de/service/a156_adjustment.pdf (English)
www.doepfer.de/service/a156_abgleich.pdf (German)

I'd recommend to measure the output voltages of the A-156 CV outputs before
you start to adjust the module. Maybe it's not the A-156 which causes the
problems. Select Major or Minor/Quint/- (not +6 or +7) at the A-156. Then
increase the CV input voltage starting from zero (e.g. from an A-176 or a
stopped A-155). The output should read 0.00V/0.58V/1.00V/1.58V/2.00V/2.58V
and so on. If there is an zero offset (e.g. 0.02V output with 0V input you
have to add this offset to each value (e.g. 0.02/0.60/1.02/1.60/2.02 and so
on).


Best wishes
Dieter Doepfer