hybrid bazz fuss questions; burning resistor? and diode selector?

[CoolJohnny]

breadboarding a nice sounding hybrid bazz fuss using a BC 108 in Q1 and an AC 187 in Q2. input is .047uf and output is 0047uf. using a germanium diode pair after the output cap. while trying various collector resistors i found 10k too low (mushy, flabby, bad decay) and about 56k perfect.

trying to go higher to see if it tightened up the sound even more proved problematic though. the resistor got really hot. when i tried wiring up a 100k pot, it started to smoke at full turn. well, obviously won't be going there again anytime soon, but can someone tell me what was going on from a mechanical perspective, and just for the sake of discussion, how high can i go before this happens (i obviously dont want to risk frying a perfectly good ge transistor by experimenting).

secondly, using an IN4148 in the feedback loop combinded with the ge diodes on the output produced great results (bright, brittle, compressed, "full fuzz face without the annoying oscillations and fartiness" kind of sound); two in series brought the gain down but sounded cool, three was amazing. instead of a gain control, i was wondering if it would be possible to rig up a pot to gradualy increase the diode-ness (sorry for noobish term) from one to three or even four. my feeble mind cannot seem to come up with how this might work though...any ideas?

[PRR]

A 56K or more resistor can NOT get hot on a 9V battery.

Worst-case: 9V across 56K is 0.16mA. 0.16mA times 9V is 0.0014 Watts. The smallest resistor you would use is 0.125W.

Larger resistor, less current, less heat.

Something is not as you reported it.

> i tried wiring up a 100k pot, it started to smoke

Sure. You can turn a pot to zero ohms. 9 Volts across zero ohms is infinite current. Infinite current times 9V is infinite Watts. Or in a real world: a 100K pot may go to 90 ohms or less, 9V across 90 ohms is 0.1 Amps, if the battery can get close to 0.1A then you have 0.9 Watts. The whole pot is rated maybe 1/4W, and you are putting all the heat in 1% of the whole pot. Yes it will smoke.

> increase the diode-ness

Yes, but to do it "well" is incredibly complicated. (The "adjustable bias diode" found in power amps is a pretty sloppy thing.) Pick a reasonable number of diodes, increase the input gain for the desired smoosh, then decrease the output gain for a reasonable level to the amplifier.