Lunar Module oscillation (fixed)

[Matt]

(This should actually be in the tech help section. Feel free to move it)
I have a Lunar Module clone breadboarded and I'm getting oscillation with certain settings. For example with the the Fuzz maxed and the gain turned below about 2/3rds and down. Seems strange. Also the gain increases as the gain pot is turned cw unless the fuzz is full cw. Then, the gain increases as the gain pot is turned ccw and begins to oscillate. 

I have tried different pots for the gain and fuzz, swapping out the 100uf caps and swapping out the transistors.

Any ideas as to why this is happening? Thanks in advance.
Changed the power filtering, works fine

[Tremster]

Really sorry to dig up this old thread. I know Drolo posted something similar about this circuit oscillating, but I can't seem to find it, maybe it was lost in the recent events.
Mine also oscillates at the settings you describe.
Could you or someone explain for the JMK PCB of this circuit (http://jmkpcbs.com/product/moon-lander/) which components you'd change for the power filtering for what values etc.?
It'd be greatly appreciated, thank you very much.

[EBRAddict]

Can you temporarily short R4 and see if that helps?

[JC103]

I have a Moon Lander fuzz from JMK and it oscillates at certain settings... not a big deal cause the sound I like is dialed in and I never use it any other way. Curious to know more about the issue though! (we used BC109's)

[Matt]

Really sorry to dig up this old thread. I know Drolo posted something similar about this circuit oscillating, but I can't seem to find it, maybe it was lost in the recent events.
Mine also oscillates at the settings you describe.
Could you or someone explain for the JMK PCB of this circuit (http://jmkpcbs.com/product/moon-lander/) which components you'd change for the power filtering for what values etc.?
It'd be greatly appreciated, thank you very much.

that would be C14. If I remember correctly I increased it to 220uf

[Tremster]

that would be C14. If I remember correctly I increased it to 220uf

Did that, great improvement, but not all the oscialltion disappeared, so I did

Can you temporarily short R4 and see if that helps?

on top and now it's all gone.
Perfect!
Thank you so much, gentlemen!

[EBRAddict]

Cool. The original schematic has that resistor before the DC filtering cap.