Hello Everyone,
I recently finished up a Madbean Dust Bunny build using all BC108's. Sounds good overall. I used an external bias pot, and I have a question regarding volume (probably a dumb question, tbh). When the pot is turned counterclockwise (voltage starve), the output volume drops. I'm assuming that's normal? When I move the bias to the proper ~4.5v range, there's plenty output on tap from the volume pot and it doesn't have to max out to reach unity gain. I checked the readings on each transistor and they all look pretty close to what's in the build guide. I just want to double check that my pedal is ok/normal, before I finish up the enclosure and call it a success. Please let me know if possible. Thanks!
The best setting of bias for transistors is when at output electrode (or collector, or emitor) is cca 1/2 of power supply, or little higher. For 9V and output at collector I would set cca 4,5-5V DC at collector. This can't harm anything.