I only had them on breadboard, but I tried a bunch of different Si transistors, a couple Ge's, and a couple combinations.
I found bigger differences between different sillicon transistors than the Ge an Si's I tried. I thought that the circuit always had a simillar character with the 2n2219s, and both the germaniums I tried (jfromel's NPN's and some PNP's from smallbear).
With jfromel's NPN Ge's, and I thought the circuit was a little more open in the mids, and maybe a little bit darker. Just a little closer to that "natural", responsive fuzz that I always want. Not a huge difference, and I really liked the 2n2219's too... I might be more inclined to mess around with the bias or just try those in a fuzzface/tonebender for something a little spittier... I thought they'd sound good there.
I thought the PNP Ge's were a little darker, and not quite as fuzzy. But they had a lower hfe, so thats probably expected. They seemed to have the biggest difference with an Si into a Ge transistor. Got a little more gain, and a bit brighter with it. I think I prefered the Si into Ge with those particular transistors.
And, with the silicon transistors, I LOVED the 2n2222's I tried (for the bass here). They were pretty dark, and had tonnes of lows. Nice pillowy low mids, instead of that farty distorted bass sound that one ends up with so much of the time. Lower gain and almost overdrivey... Not really punchy, but that's why we have more than one pedal. I meant to try a high gain Si transistor for Q1 to see if I could get something similar but pushed a little harder but never got to it.
The usuall 2n3904/6's and 2n5087/8/9 were nothing special... Not bad, but just not as fun or unique as the others i had tried...
So, since all I did with the Si's was grab them by model number, there's probably more that could be done with matching them up and whatnot. I think that in the end, the material wasn't really the biggest thing, but that the other parameters I don't actually understand probably just as much to the sound.
Otherwise, thats about where I was at for transistors. But take it with a grain of salt... I don't have the ear for guitar effects that I'm sure most of you do, and I'm pretty inexperienced with all this. Anyone else want to give some thoughts?
And here's the painting on the first. I like it, but the little details I missed bug me, so the next one should be a big step up. I need to trouble shoot the circuit, I think I cooked something putting it together and haven't had time to take a good look at it.
Things I learned painting:
1) Less Whiskey, more patience and planning
2) Get a couple cheap paintbrushes... Anything's gotta be better than the mangled brush on the bottle and a toothpick.
3) Draw the designs on first (with room for the knobs and washers) instead of freehand.
I'm looking forwad to doing box #2.