It's in the service manual for the A-110: http://www.doepfer.de/a110_tec.htm

Details are on the circuit diagram, and for extra clarification, I found this (Google translate will be your friend here!):

http://modularne.info/ p=713

There's a few other scraps scattered around, but the circuit diagram basically tells you pretty much everything you need to know.

My modification is different to the Polish site, and more in line with the service manual; i.e. a jack straight to the Soft Sync pad, and another jack into an attentuator then to the Linear FM pad. I didn't bother with a switch for the AC/DC toggle, as I'll almost always FM with an audio source, so can leave the jumper open.

My end result can be seen here:

http://www.modulargrid.net/e/other-unknown-a-110-vco-linear-fm-soft-sync

I fitted a pair of pins to the appropriate pads on the PCB so that I could plug and unplug the extension module if required, rather than having it permanently soldered to the A-110.

Note that the modification will void your warranty, so undertake the change at your own risk!

Hope that helps.

Cheers,

Dave.

--- In Doepfer_a100@yahoogroups.com , achtung_999 <heinrich.himmelwasser@...> wrote:
>
> Dave, where is the info for this modification found
> Thanks!
>
>
>
> On Tue, Jan 1, 2013 at 11:14 PM, woof_dave <David.Woof@...> wrote:
>
> > **
> >
> >
> > Further digging has answered this for me - close for DC FM (i.e.
> > continuous source voltage), open for AC (i.e. audio).
> >
> > It's all there if I look for it ;-)
> >
> > Dave.
> >
> >
> > --- In Doepfer_a100@yahoogroups.com , "woof_dave" <David.Woof@> wrote:
> > >
> > > Hi,
> > >
> > > I'm adding the extra connections, etc, to make the linear FM change to
> > the A-110 VCO, and it isn't clear to me whether the "AC/DC Coupling" jumper
> > should be open (as per the default), or closed when the linear FM addition
> > is made.
> > >
> > > Anyone know which state it should be in
> > >
> > > Thanks,
> > >
> > > Dave.
> > >
> >
> >
> >
>
>
> [Non-text portions of this message have been removed]
>