Hello there !
Just a few tests with different clipping diodes in a TS-like environment. We are here talking about soft clipping (eg op-amp feedback clipping).
OK, here is the sample :
- At 0:00 : clean (pedal is off)
- At 0:07 : 2 classic 1N4148 (anti-parallel pair)
- At 0:21 : a pair of 1S1588. I hear the same sound as made by a pair of 1N4148 …
- At 0:36 : a pair of full-of-mojo MA856. Here the sound is different, maybe just because it is a bit louder. Threshold voltage of 0.7V for a MA856, instead of 0.58V to 0.6V for a 1N4148 or a 1S1588. Is this the only parameter involved that makes the audible difference?
- At 0:56 : 2 pairs of 1N4148 (2 diodes in series, 2 diodes in series, anti-parallel mounted). Louder. Threshold voltage doubled, eg 1.2V
- At 1:15 : a pair of JFET transistors IRF 520N. Muddy and low level output. Interesting “honk” anyway, and interesting sound when acting on the treble pot ! (for this sample, the treble pot has always stayed in mid position). Quite fun is to notice that, when used is hard clipping (series shunt type to ground), JFET IRF 520N and 1N4148 sound quite exactly the same way …
No (ugly test) pedals nor guitars were harmed during the making of this test !