Zygote with Si PNP

[pgodfrin]

Howwdy, I'm usng BC560 transistors in my Zygote. I'm getting input at the base, but nothing out of the emitter on Q1. Erm, will the BC560 work with this circuit?

[mauman]

Q1 emitter (rightmost pin) is grounded, output should be heard on Q1 collector (leftmost pin).  BC560 should work if inserted with collector on the left, emitter on the right (flat side south), although it may have more gain than the Ge PNP this design anticipates.

[pgodfrin]

Thanks, I'll check. May be a bum transistor. What happens if the gain is higher than the design calls for?

[mauman]

More fuzz, less able to clean up when you roll down the guitar volume knob.  Not better or worse, just different!

[pgodfrin]

OK, so the datasheet says from 1-3, flat side on top, C B E.
I tried it both directions no joy. Got input at the base, but no output in either direction. That would be collector grounded, or emitter grounded. I'm really confused at this point.
I thought PNP has the collector at ground...
sigh

[mauman]

Your 1044 IC inverts the power, so you have -9V (approximately) coming off pin 5, thru R2 to the collector of Q1.  The Q1 emitter is grounded, but in this case "ground" is more positive than "battery" since battery is -9V rather than +9V.   So you're right in the sense that the collector of a PNP is negative with respect to the emitter, but in this case it's because of the negative power supply.

Can you pull Q1 and Q2 out and read the voltages on each one's C-B-E relative to ground with the power on?

[pgodfrin]

Oh cool, clearly you understand this stuff, I just read the directions and put them together, lol!
Yes I can make those measurements, I;ll get back to you.
Thanks!!

[pgodfrin]

sigh... I tried with a brand new transistors, and nothing on the output.

[mauman]

Voltage measurements at the transistor sockets, with the transistors out?

[pgodfrin]

Sigh, I was having trouble with that, I'm not sure if it's pilot error or my DMM is on the fritz...

[pgodfrin]

oh  misunderstood. You're looking for the voltages on the pcb, with the transistors out!!!

[mauman]

Right, I'm thinking there may be a problem with the power, since flipping transistors around and changing them didn't do anything.

[pgodfrin]

OK, from the copper side, w/8.94 V supply:
Q2 - 25 mV : .363 V : 8.16 V
Q1 - 0.5 mV :  20 mV : 0.364 V

hmmm, I wonder if Q1 value .364 should be closer to 8...

[mauman]

Yep!  With Q1 and Q2 removed, you should read -8 to -9v on the collector of Q1 and Q2, and the base of Q2.  Q2 collector has good voltage, so your -9V supply is good, so check the -9V path from pin 5 of the inverter thru R2 to the collector of Q1 and the base of Q2. I would suspect R2 - wrong value, open solder joint, etc.

[pgodfrin]

Will do! Thank you very much.