Messages

I think I have figured it out.  Thanks for all of your help!

It looks like Q4 (2n7000) was bad.  I guess I'll be making another order to Stompbox parts! I got the original 2n7000 from Tayda, so I don't know if it was bad from the factory or I destroyed it with my soldering skills.

To figure it out, I removed the LEDs, but the problem was still there.  Next, I removed Q4 and I was able to get clipping and a volume boost.  I placed sockets for Q4.  When Q4 was placed, the problem returned.

As an update and for advice:

To date, I have check the following:

1.  Continuity between the toggle (and toggle lugs), IC (pins 1 and 2), diodes, 2N7000 and LEDs.  All connections were correct. 
2.  Voltages have all been verified from IC, 2N7000s, and MPSA18's as correct (based on Madbean voltages given). 
3.  Audio-probed the circuit, including the clipping section, and I have sound in the appropriate places.
4. Reflowed the clipping section of the circuit.
5. Removed LEDs to determine if sound was only going through the LEDs when toggled to run through the FETs.  With LEDs removed, I still obtain clipping with the toggle in LED and diode (1n914) settings (curious finding).  The clean sound is still present with the FET toggle setting.  In other words, no change.



I am going to try the following to further detect the problem. 

1.  Remove Q4 (2n7000).  If no change, then proceed with Q3 and D5 (1n34a).
2.  Remove D3 and D4 (1n914). 
3.  Lastly, remove the toggle switch.

What do you all think?  Good plan of attack or am I wasting my time?  Thanks again for the help.  Cheers.

Great suggestions. Continuity was seen at all the suggested points and toggle switch. Am I correct to think that I now have an issue with a a FET or diode? Thanks again

Just made the Greenbean (TS inspired clone). I was rocking before boxing and wondered if I have a problem. With the clipping toggle to the FET, I am getting no clipping. It is essentially unity sound. The pots all work and effect the signal appropriately. All power measurements match those given by Madbean.

I made a few substitutions due to availability. The BAT41 was changed to a 1N34a. Transistors are MPSA18.  The voltage across the 1n34a was 0.04 v.

With this in mind, is the FET supposed to clip (overdrive) the signal? Is the 1n34a or 2n7000 bad or is something else amiss?