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Hey everyone!
Long time listener, first time caller. (NOT!!)

Symptoms of pedal:
When I plug into the pedal and the pedal is in by-pass, I have to turn up the volume knobs on the guitar and amp to 100% to get a sound level equal to the sound level of an un-amped acoustic guitar (guitar-pedal-amp = signal chain) When I engage the pedal the pedal does exactly as it is supposed to (volume and treble knobs function properly). However the total output is way quieter than it is supposed to be.
I'm including a photo of the IC pin voltages and just for reference I am using an MXR ISO-Brick power supply. If need be I can unbox the unit and send photos. For reference, I have swapped out the TL072 and the 7660S. The 7660S was bad out of the box and I went through my stash of 25 or so only to fine 2 good ones! I guess the guy in charge of QC was off that day.

As always, thank you all in advance, for your time!

Steve0

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“To know, and not to do, is not to know”

The IC voltages look good with the possible exception of pin 4 of the 7660S which shouldn't be that negative; I'd expect about -4.5V. You may want to re-check that reading. But I don't think you have an IC problem.

Sounds like your signal is being (mostly) lost to ground. First thing I would check would be the wiring of the two I/O jacks and make sure you don't have one of the signal-carrying wires shorting against the inside of the metal enclosure. As I'm sure you know, there's not a lot of room in there!

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“My favorite programming language is SOLDER” - Bob Pease (RIP)

My Website * My Musical Gear * My DIY Pedals: Pg.1 - Pg.2

You were correct. The pin 4 voltage is -3.7v.



Taking a closer look, I had the output signal wire attached to the 'ring' terminal. After relocating it to the 'tip', it boosts quite nicely!

Thanks again Bob for your most helpful insight!

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“To know, and not to do, is not to know”

Yeah, I thought it must be something like that because the problem was evident in bypass mode, when none of your audio signal was going through the effect circuit on the PCB.

Glad to hear you got it sorted out. That 27V Boost is quite the little powerhouse!

_________________
“My favorite programming language is SOLDER” - Bob Pease (RIP)

My Website * My Musical Gear * My DIY Pedals: Pg.1 - Pg.2