Doepfer

Hello,

I have 2 A-110 VCOs and both produce very dirty sine waves.  I was 
wondering if there is a way to calibrate the A-110 to produce much 
cleaner sine waves.

Thanks,

Ethan

Hi ethan

> I have 2 A-110 VCOs and both produce very dirty sine waves.  I was
> wondering if there is a way to calibrate the A-110 to produce much
> cleaner sine waves.
The A110 contains the most rough version of a often used circuit for sine
shaping. This one uses two diodes (see http://www.doepfer.de/a110_tec.htm the
part in the lower right part of the schematics.). You may enhance this circuit
with more diodes and resistors. Some theory about this can be found at:

http://www.geocities.com/SoHo/Museum/4459/circuits/sineshaper.html

The schemo from Tietze/Schenk is on 
http://www.geocities.com/SoHo/Museum/4459/circuits/tzsinesh.gif

Hope this helps.

Florian
-- 
Florian Anwander                  |ConSol*  HP-Support
Tel.   +49.89.45841-133           |Consulting&Solutions Software GmbH
Fax    +49.89.45841-139           |Franziskanerstr. 38, D-81669 München
email: florian.anwander@consol.de |http://www.consol.de

Hi Florian, thans for these infos. Sinewave are always very important 
in my moduar-patches. All these sine-waves found on modulars sound 
way different. The 110 isn't clean at all, but has balls, where the 
111 has a much cleaner sine-waveform, but hasn't balls. I really like 
the Sine produced from a Blacet Final-Filter in Selfoscillation, but 
it doesn't track well. The Wiard VCO's sine is completely different 
than all the others. Rather clean (but) very nice. Two of these in 
lin FM gives some very warm and clean FM-patches. I talked to Jürg 
Oldani recently and he told me that the sine-waveforms in his huge 
Selector-OSO-Module are a very special and complicated design, much 
more advanced than in his (nice!) VCO. I really can't wait to hear 
it. (btw: did you ever test the selector in Keys?).

That sounds I as am a complete hardware-whore (which is true). But I 
make music with these things all the time, so it is no detail for me. 

Olivier 


> The A110 contains the most rough version of a often used circuit 
for sine
> shaping. This one uses two diodes (see 
http://www.doepfer.de/a110_tec.htm the
> part in the lower right part of the schematics.). You may enhance 
this circuit
> with more diodes and resistors. Some theory about this can be found 
at:
> 
> http://www.geocities.com/SoHo/Museum/4459/circuits/sineshaper.html
> 
> The schemo from Tietze/Schenk is on 
> http://www.geocities.com/SoHo/Museum/4459/circuits/tzsinesh.gif
> 
> Hope this helps.
> 
> Florian
> -- 
> Florian Anwander                  |ConSol*  HP-Support
> Tel.   +49.89.45841-133           |Consulting&Solutions Software 
GmbH
> Fax    +49.89.45841-139           |Franziskanerstr. 38, D-81669 
München
> email: florian.anwander@c... |http://www.consol.de