Doepfer

> Hi all,
>
> Just wondering if anyone else has the combination of A-112 and R2M.
> I've just discovered a potential problem with mine that I'm trying to
> work out and was wondering if anyone else can replicate the problem....
>
> Simply put, the Gate out of the R2M doesn't seem capable of triggering
> the gate in of my A-112. I can trigger other things with it (eg. A-140
> ADSR or A-198) but no joy on the A-112. On the other hand, I can
> trigger the A-112 with an LFO.
>
> Perhaps I'm doing something wrong or perhaps the A-112 requires a
> gate/trigger of higher voltage than the R2M can deliver ?
>
> Any help or confirmation appreciated.
>
> Cheers
>
> Simon

Christian tested the R2M/A-112 combination and indeed it does not work. The
reason is that the Gate input of the A-112 has a load of ~ 10k to GND. This
reduces the +5V Gate voltage coming from the R2M so that the A-112 does not
trigger. Within the A-100 the problem does not occur as the A-100 modules
have more powerful outputs and the gate voltage does not collapse if the
A-112 is triggered by another A-100 module.

If you are a bit experienced with eletronics there is a simple solution:
replace the 10k resistor R15 on the A-112 board e.g. by a higher value (e.g.
47k or 100k). R15 is located near the Midi In socket between the 100n
capacitor C21 and the Z-diode D5/4V7.

As long as the A-112 is connected to a gate source (e.g. R2M or the output
of an A-100 module) R15 can be even removed (simply pinch it off on one
end). But without R15 the A-112 may trigger accidentially if nothing is
connected to the Gate input. If this does not matter R15 can be removed.
Otherwise I'd recommend to use a higher value as mentioned above.

Hope this helps

Dieter Doepfer