freestompboxes.org

I had never heard of this company, headed by https://www.linkedin.com/in/richard-mintz-67603124
They even built stuff for Maestro...

I think I may have their volume pedal. I'll check tomorrow.

Here my guess of the schematic in accordance with the PCB shown above, as far as the components could be identified.

I'm sorry, I drew the circuitry wrong, here the corrected schematic:

Why the hell does the edit function sometimes not work?
C2 was still incorrectly marked, here again the schematic:

Nothing to do with this, but woah...can't help but notice the "British Steel" looks almost the same as the Paranoid

I found out that the right transistor is an E201 JFET due to the case color, this is the predecessor of the J201 JFET.
I ran a simulation of the circuit with a J201 and a 2nN5088 transistor choosing the unknown capacitors so big that they have no influence on the signal.
The circuit works fine with these both transistors.
The maximum gain of the booster is 10 as expected,this is determined by R9 divided by R3.

R1 looks like 470k and R3 6.8k

Intripped wrote:R1 looks like 470k and R3 6.8k

Thanks, you are right.
Sorry, I probably copied the part in the layout and forgot to change the value.
The simulation gaves a gain of 2.9 with the corrected values.
Here the corrected layout and schematic: SprintLayout6.0-file:

Any insight into the feedback(?) between the two transistors, R9 and C2?

C2, R9 and R3 form the negative feedback loop.
The gain Au = Ao/[1+A0*R3/(R9 + ZoutStage2)]
Ao is the open loop gain when R9 and C2 are omitted.