MODIFICATION The FZ-1 - CB style

I don't like to encourage off-topic discussions, but I'll answer the last two questions, then I'm done.

The STABILITY control allows the various stages to talk to each other via the power supply rail. Normally not a good thing, but it can be used to create oscillation, gating and other weird behavior.

That 47uF cap is for filtering power supply noise and is on the upstream side of the STABILITY control, so it has no effect on how the STABILITY control operates.
 
I've breadboarded this and a few other germanium circuits and tried them with about 2 dozen different soviet era PNPs. I continually run into issues with very low volume. This was the case when breadboarding this circuit as well. Is that an issue with too much leakage? I get decent fuzz tone out of this, but it's sucking the volume out. Had the same issue with tone bender MKI and II. Can you point me in the right direction in terms of debugging this? I've adjusted the resistor values to get reasonably close values to what smallbear recommends

Here are the transistors that sounded best:
PositionTransistorhFELeakage
Q1ASY33S6638µA
Q2МП2012686µA
Q3МП20213488µA
 
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What voltages do you have on Q1-S, Q2-C & Q3-C? Bear in mind (pun intended) that Small Bear's Fuzz circuit runs on 1.5V. This circuit runs on approx 3V, so you need to double the voltages that SB recommends to get the bias in the ballpark. If you are building the circuit I describe in this thread, then you should be using NPN transistors because this circuit has a positive power rail.
 
No I built the small bear version, including the 1.5v step down. It's running at about 1.79v, but that shouldn't be an issue, right? The values I get:
Q1-E: .625v
Q2-C: 1.05v
Q3-C: .606v
 
Those voltages look reasonable. I suggest that you open a troubleshooting thread in the the Troubleshoot forum. Be sure to post detailed photos, schematic, etc.
 
Ge PNPs tend to have lower leakage. In fact, I could not find any PNPs in my stash that had enough leakage for this circuit. Maybe yours will be leaky enough.

You're actually pretty close. Flip Q2 & Q3 upside down, so the emitter is at the top.

Connect R16, R17 & VOLUME to GND, not Vref (3V rail).

C3 should connect to the other end of R6.

Plan on fiddling R5 and/or R8 to get Q2-C to somewhere around 1.5V when ATTACK is dimed. Make sure you get good tone over the full range of ATTACK.

Plan on fiddling R10, R11 and/or R12 to get Q3-C to somewhere around 1V, then tweak by ear.

If you have to go more than 2X in either direction, then try a different transistor. Ge circuits can be very finnicky and this one is no exception. It requires a lot of patience to dial-in. Even once it's dialed-in, the bias will drift when the temperature changes. R9 and R13 help stabilize the bias, but it will still drift a little.
 
This is immensely helpful. Thank you! I just tested about 30 PNP GEs for leakage and gain, so hopefully I've got some that fit the bill. What value ranges am I looking for for ballpark starting points?
 
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