[sdiy] Variable slope with a SSM2164

[René Schmitz]

Hi Aaron and all,

Aaron Lanterman wrote:

> So, I suggested he try Rene Schmitz's MS-20 clipping circuit, with the 
> LEDs. I haven't heard what it sounds like myself, but my student said he 
> didn't like the way it sounded. (He hasn't spent a lot of time with a 
> real MS-20 though, but here I was hoping to go for something more smooth 
> than an MS-20 anyway).
> 
> Any other ideas re: the clipping? Maybe try something more like in the 
> original MS-20, with the three diodes?

The thing is that the MS20 filter tops off the gain, to unity, with no 
limit of amplitude (for high voltages its a simple gain stage, with some 
crossover distortion). Whereas a "real" clipper would have a (local 
differential) gain of 0, and delimits the amplitude to some maximum.

I don't exactly know what you're up to, but I suspect that the "way it 
sounded" might be due to an unsuitable application of this piece of 
circuitry. Changing from LEDs to Si diodes will not dramatically alter 
that, if at all.

My suggestion: Try a voltage divider with say 10k (for starts) on top, 
and two antiparallel stacks of three diodes (or just one green LED...) 
at the bottom. This does delimit the amplitude, where as the Korg 
circuit does not.

Cheers,
  René

-- 
uzs159 at uni-bonn.de
http://www.uni-bonn.de/~uzs159