[sdiy] Discrete Op Amps

[Mattias Rickardsson]

On 9 April 2017 at 18:32, Gordonjcp <gordonjcp at gjcp.net> wrote:
> On Sun, Apr 09, 2017 at 11:19:48AM -0500, mskala at ansuz.sooke.bc.ca wrote:
>> On Sun, 9 Apr 2017, Gordonjcp wrote:
>> > They don't really make that much difference.  Certainly there's
>> > absolutely no point doing all the crazy stuff that the "boutique pedal"
>> > idiots do, like having switches to choose which colour of LED you use
>> > for the clipper.
>>
>> Different colours of LED have different forward voltages, so this would
>> make more sense than some of the other things they do.
>
> The curve is the same shape, so varying Vf would just alter the point where clipping starts - much the same as twiddling the gain pot.

Unless you use more components than a diode in your circuit.

Typical distortion circuits use series R and parallel C nearby the
diodes, and then the different diode curves shifts the small-signal
gain and the large-signal gain in different amounts resulting in
another shape on the distortion curve, and the effect of the C varies
too.

/mr