Doepfer

Hi Ingo,

Thanks for the interesting comparisons! I'm quite surprised that 
there is any difference at all between the original state and with c1 
shorted - I'm wondering whether the A-111 sine-shaping can introduce 
DC into the signal (I'll check it out when I get the chance). Since 
the CGS one is so simple, I may have a go at simulating it to see 
what it looks like - *if* I can mimic the transformers and germanium 
diodes appropriately. It would also be interesting to hear how harsh 
the EFM one sounds alongside these - from memory it is designed so 
that it hard-switches one set of transistors in the MC1496, and so 
introduces all the odd harmonics of one of the signals.

Also thanks for picking up on an error of mine, that the other cap to 
try is in fact C1 and not C10 as I was calling it - I don't have the 
benefit of the schematic in the service manual, and I obviously 
saw 'C1 0.1u' on the silkscreen as 'C1 0' and hence C10, and once I'd 
written it down, its fate was sealed! I have corrected the one gif I 
uploaded to the files section.

Tim

--- In Doepfer_a100@yahoogroups.com, "selfoscillate" 
<synaptic_music@y...> wrote:
>
> 
> hello,
> 
> yesterday i modded an a114 like suggested
> by peter and tim. when testing the device
> i compared it with other ringmodulators.
> here is a short recording to show the
> timbral differences and also the varying
> loudness.
> 
> http://www.selfoscillate.de/a100files/ringmods-sequence.mp3
> 
> file size: 429 kb
> 
> all ring modulators use the same audio sources
> (sinewaves from two a111, each vco's pitch is
> controlled by it's own sequencer row).
> 
> 1. a114 original
> 2. a114 tim's mod (c1 shorted)
> 3. a114 peter's mod (c2 shorted)
> 4. blacet klangwerk
> 5. cgs real ring modulator
> 
> 
> best wishes
> 
> ingo
>