My Aries modular VCOs have a triangular core that also forms the square and sine output.
There's a second sync'd core for sawtooth output (so no glitch). It's their differential
transistor tri-to-sine converter that makes the high quality sine output.

Moog, Arp, Polyfusion, etc. all used this standard circuit to make their high quality tri-to-
sine conversions. Looking at Doepfer schematics, all his oscillators (except the quadrature)
use that cheap simple diode converter. I'm guessing Dieter chose this for cost rather than
quality reasons. I was expecting the expensive High-End VCO to be better quality.

BTW, I was really tempted to get Tip-Top, but that video shows a distorted sine even
worse than Doepfer! Makes me wonder about the design quality inside...

--- In Doepfer_a100@yahoogroups.com , Argitoth <argitoth@...> wrote:
>
> So far I think from best to wrost, (but I'm not so sure) it's
>
> 1. Plan B VCO Sine (good)
> 2. Tip Top Audio VCO (a little better than Analogue Systems Never
> owned one of these)
> 3. Analogue Systems VCO Sine (bad)
> 4. Doepfer A-110 (worse)
>
> Laryn91, your vintage MODULES or your vintage tabletop/rack/keyboard
> synths Don't forget that all my filter modules produce very clean
> sines. Also, I believe the quality of the sine has to do with its
> oscillator core. I think to get a clean sine requires a second VCO
> within a VCO... as in, one module has to house two different
> oscillator cores. One for square,tri,saw, and another separate one for
> sine... but I don't know anything about circuit boards, this is just
> my guess. I think this is easily done in a self-contained synth like
> your vintage gear because it's one whole system, not a bunch of
> modules... or something... know what I mean
>