Germanium fuzz: the quest continues!

[Steben]

So simple I never came up with it.
If you have got very very slight gain in a common emitter stage (Re a bit smaller than Rc), followed by a buffer...
The point is to get a "opamp" signal at the input that's quite large, but not too big, enough to get the base-emitter in soft saturation in each stage, not clipping the output. That's exactly what happens in a TB MkIII, by the way, but only with one tranny and a diode. Or even softer in a Rangemaster.

[DDD]

Seems to be interesting.
At the same time the followers may be based on PNP tranniers thus making matching of DC levels more easy?
Besides,  Ge PNPs are not so rare as NPNs.

[Steben]

Now we're getting somewhere!
bias should be set to soft break-up as biasing a Rangemaster, but even less than 1V according to the transistor.
Q1 can be even silicon if biased right. Q2 should be germanium.
result should sound like a super softy fuzz face, ...
Yes, let's call it the "Overdrive Face".

[Steben]

Seems to be interesting.
At the same time the followers may be based on PNP tranniers thus making matching of DC levels more easy?
Besides,  Ge PNPs are not so rare as NPNs.

Well, in the newest schematic above you simply can swap polarities. But don't be shocked if I tell you you can get softy with silicons too, as long as you bias them accordingly. The ratio signal/clipping area should be linear. Which means with silicons you need even less bias at the bases (almost the cut-off 0.6V itself). In relation to the signal, the clipping is less hard then. You will get different gain and output levels however.

[Steben]

I've put it into spice (alas silicons only) and it seems fair for the upper signal half at the output. At Q1's base biased at 0.8 to 0.7 Volts it is soft squashed as we knew it in the RM. Spice calculated the negative half quite harsh however, mostly because of the big signal at Q1's collector I guess. I guess getting the Q1's base even more low (0.6 Volts perhaps) could lower the gain.
But on the other hand: Why build a fuzz/overdrive without the overdrive?
Holidays are coming and I guess I will be soldering between the family dinners...

[bioroids]

Hey Steben, you should try all this on the breadboard.

You really need a good model of the ge transistors and the guitar pickup to take the simulations seriously (that is, to see the nuances of the clipping).

Have you tried the Sziklai fuzz?

Miguel