Box and All (EQD tone job) issue

[Roman_K]

Hello everyone!
I have breadboarded the pedal and everything is fine except one thing: when I hit strings, there is a high-frequency hiss.

Here is a video for demonstration

I did some research and measurements, and found out that the input part of the schematic is similar to the input part of the blues breaker, where the voltage on the non-inverting input is about 3.9V. Mine is about 2.1V. The other voltages are fine, I have 4.5V exactly where it should be. I'm pretty sure that low voltage causes my signal to distort, because it has very little headroom.
I am asking anyone who has the pedal to measure the voltages on the op amps. It would help me a lot to prove me right or wrong and figure out what's going on. Any advice is welcome! Cheers!

I hope that someone gets my
message in the bottle, yeah
message in the bottle, yeah

 

[Robert]

Measure the voltage on the output (pin 1) of IC1.1.

With a 1M pull-up resistor your DMM is likely loading down the voltage while making the measurement.

 

[Roman_K]

Measure the voltage on the output (pin 1) of IC1.1.

With a 1M pull-up resistor your DMM is likely loading down the voltage while making the measurement.

Hello, Robert, and thank you for replying, hope you're doing fine.
pin 1 and 2 - 3.66 V