Hello Andy,

over the years 3 different version of the A-131 were manufactured. For
details please refer to our website:

www.doepfer.com > English > PRODUCTS > A-100 > Module Overview > A-131

Only for version 2 (with CA3080) it was possible to trim the exponential
scale a bit by means of P7 (2k5 trimming potentiometer at top left corner of
the pc board).

As already mentioned by Florian for exponential VCAs the amplification scale
differs clearly from linear VCAs.

Best wishes
Dieter Doepfer

> -----Ursprüngliche Nachricht-----
> Von: Doepfer_a100@yahoogroups.com [mailto: Doepfer_a100@yahoogroups.com ]
> Gesendet: Donnerstag, 21. Februar 2019 12:09
> An: Doepfer_a100@yahoogroups.com
> Betreff: 1 Doepfer A-131 exponential VCA - calibration
> procedure
>
>
> Is there a calibration procedure document, for the Doepfer A-131
> exponential VCA
>
> I bought one used, a while ago, and I've never been sure it's set
> up as it should be. It tends to go from a little bit too quiet
> to way too loud, rather suddenly, making me fear for my eardrums,
> on headphones - which makes me wonder if the previous owner
> fiddled with it, then gave up on it.
>
> - Andy