Darlington for output transistor

[Crazyyellowfox]

I'm not doubting that this has been tried, but an NPN darlington works nicely for the output transistor,
some tweaking with the biasing is required, but you can get a nice hot output with an MPSA13/MPSA14
I was also able to coax a darlington pair of two Russian NPN germaniums (mp10) to work for a nice
buttery midrange. in conjunction with two hfe-matched 2SB324 PNPs.

[blackcorvo]

i did some tests but i only have BC517 darlingtons, and AC107, that were the only germanium PNP transistors i could find here in my town. there's only one place that sells N.O.S. electronic components but they only gave me this model when i asked for germanium transistors... and this one is weird because the red dot close to one of the leads poits the Collector, and the usual - as i heard/searched - is for pointing the Emiter...
I also played with the diode a bit, trying Leds, Zenners, Germanium and Schottky. Myself i preffered the Zenner and the red Led, because they didn't clip too early like the Germanium and Schottky ones. About these two, i think the Germanium sounded best. The schottky sounded too compressed and distorted to my taste. i really like a louder output with less distortion for building clipping modules, so i can use a little trick: i put zenners just after the output capacitor, in way they do the clipping by their voltage, wich gives a little compression in the wave before the "real" clipping, then i put a small resistor in series with the output (nothing higher than 2k, usually 330R), and after this resistor i put the clipping diodes in the usual config. for me it sounds great.

that is another idea people couls use for building distortion circuits: putting clippers in a "cascade" config like that to get different flavours of distortion.

[borman09]

An operational amplifier ("op-amp") is added in the circuit.