I etched a PCB from the Zombii PDF. At first it didn't work, then it worked briefly so I went to drill the enclosure. Then when I went back to try difference transistors to see which I liked best, the circuit didn't work again.
What should the voltages be for all the transistors?
Q1 (2n3904):
E - 0v
B - .692v
C - .154v
Q2
E - 9.3v
B - 9.3v
C - 8.63v
Q3
E - 8.9v
B - 8.6v
C - 8.92v
anyone please?
The collector voltages will depend on where the Stab knob is set actually. In any case, those voltages do look very off. What type of transistors are you using and are you sure you have them oriented correctly? Have you check the board carefully for any trace breaks or solder bridges?
Quote from: madbean on July 22, 2012, 02:31:20 AM
The collector voltages will depend on where the Stab knob is set actually. In any case, those voltages do look very off. What type of transistors are you using and are you sure you have them oriented correctly? Have you check the board carefully for any trace breaks or solder bridges?
The stab was fully clockwise - no oscillation.
Yeah, the transistors are oriented as in the layout - the little tab on the Q2/3 matching that of the layout in the pDF. I'm using AC128s now, those voltages were measured with some 2N404As.
I think I've remedied the problem, the pedal works, though every now and then I get a scratch or some light noise.
Noise does tend to go hand in hand with this one. But, are you getting the FF sound, too?
Can someone post the correct voltages for the zombii??