[sdiy] Discrete Op Amps

[Gordonjcp]

On Sun, Apr 09, 2017 at 05:05:34AM +0000, cheater00 cheater00 wrote:
> Modern op amps might have better gbw, noise, etc, but older op amps
> (discrete or not) might have characteristics that you desire. For example,
> they might clip or sag in a specific way that is desirable. The thing is,
> that sort of thing is mostly inaudible on simple sounds - the more complex
> a sound the more "magic" you can work. So on the voice mixer - yes. On an
> instrument effect, mixer channel, etc. Last op amp of a synth voice, maybe.
> Vca, maybe. Op amp after filter, or in filter, maybe. Vco mixer before vcf
> is pushing it. Before that don't bother. There's a place for them and if
> your budget allows them, go wild. However most synths contain very many op
> amps so making them expensive could easily spiral out of control.

That doesn't really happen though.  All opamps sound pretty much the same.  All distortion pedals sound pretty much the same too, and it's really only the frequency response - which is not determined by the distortion "shape" - that gives it a particular tone.

Building discrete opamps to chase a particular distortion shape is the sort of thinking that leads to folk buying specially-imported hundred-dollar rocks to damp out vibrations in their mains cables.

-- 
Gordonjcp MM0YEQ