[Chris S]

Insulating the treble pot with a piece of painter’s tape seems to work.

I have plastic covers on all of the pots, I did some audio probing on each contact point for all the pots, nothing there.

The pedal is now pretty loud and has some nice tones through the whole gain sweep.

 

 

[Chris S]

I replaced the gain pot with a 250k and the 8K2 resistor to ground, much smoother gain sweep!

As far as the volume drop, with an audio probe I figured out the treble pot is shorting somehow.

When the pot comes into contact with the case it drops in volume, I looked at the schematic and it seems like none of the 3 connections for the treble pot are supposed to connect to ground.

 

 

 

[Chris S]

The only thing I can see that’s incorrect in your build is R11 3K9 in the build doc, yours looks like 39K

Eureka! That was it!

I’ll need to practice identifying resistors by color band more quickly.

I didn’t have a 3K9 on hand (have some 3.3K and 4.7K) so I put in a socket for R11 to try both, and 4.7K seems to solve my issues with biasing Q3.

Now the decay is much more natural and musical, low E strings ring out in a distinctly metal way.

However, with the volume all the way up, it seems to be at least 6dB quieter than the bypassed signal.

And the A1M gain pot seems to not have much sweep at all, silent, then about an 1/8 of a turn gives me 80% of the gain. I’ll check out your suggestion re: the gain pots and dig further into the old threads.

Thanks for your help, Billy

 

[Chris S]

I swapped R27 and R29 and it came to life!

Expected

R27 – 33K

R29 – 47R

Actual

R27 – 47R

R29 – 33K

Looks like R29 is in the power section of the schematic, I’m guessing the 33K was preventing the transistors from getting powered correctly?

I typically measure every resistor before soldering, the instructions had a lot of listed modifications (ex. 22K sub for 33K) So I socketed (what I thought was) those pins and must have mixed them up the next day when I went to solder the rest of the components.

This is my 21st kit build and I’ve never run into a misplaced resistor (that I know of). My last build that didn’t work I had the triangular mount transistors rotated incorrectly, so I was “biased” towards thinking it was a problem with the transistors.

I’ll look into getting a transistor checker, I was a bit afraid that one of the 9 was defective and I wouldn’t be able to measure it, in addition to really wiggling the transistors and making sure they’re in there tightly.

Thanks mybud and Playsforfun for your help!

[Chris S]

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