Low Tide distorts signal and too loud.

LJSJS

New member
I built the Low Tide PCB, but it produces very strong distortion and the sound is too loud. I’ve tried adjusting the BBD Bias trimpot and Gate trimpot, but the issue persists. Notably:

  1. The distortion and noise still occur even when the Mix knob is set to 0.
  2. The modulation does not seem to work at all.
  3. The gate function works, but when it engages, the volume increases significantly.
  4. There are no issues or noise when the guitar is not being played or when the pedal is bypassed.
Currently, I’m diagnosing the distortion issue by measuring voltages at key components, but this is my first time working with circuits, so I’m not sure how to determine if the values are correct. Here are the voltages I measured so far:

Q1 - 2SK208-Y:

  • Source: 4.96V
  • Drain: 0.3V
  • Gate: 0
Q2 - 2N3904:
  • Collector: 8.7V
  • Base: 4.96V
  • Emitter: 4.33V
Q3 - 2N3904:
  • Collector: 5.15V
  • Base: 4.07V
  • Emitter: 3.54V

Q4 - J201:
  • Source: 0.21V
  • Drain: 5.1V
  • Gate: 0
Q5 - 2N3904:
  • Collector: 8.7V
  • Base: 5.12V
  • Emitter: 4.46V

IC1 - LM78L05:

  • Input: 8.7V
  • Ground: 0
  • Output: 5.04V
IC2 - Randomizer:

  • Pin 1: 4.71V
  • Pin 2: 4.61V
  • Pin 3: 5.01V
  • Pin 4: 0
  • Pin 5: 5.04
  • Pin 6: 5.01
  • Pin 7: 5.03
  • Pin 8: Moves randomly from 1 to 4
IC3- LM13700N:

IC4 - LM258P:

  • Pin 1: 0.01
  • Pin 2: 2.51V
  • Pin 3: 2.5V
  • Pin 4: 0
  • Pin 5: 8.7
  • Pin 6: 2.14
  • Pin 7: 2.14
  • Pin 8: 2.14
IC5 - MCP602 I/P
  • Pin 4: 0
  • Pin 8: 2.14
IC6 - CD4046BE
IC7 - V3207D


Some of the ICs have fluctuating values, so I wasn’t able to get consistent measurements.

If there’s anything I might have missed or additional steps I should take, I would greatly appreciate your advice.
 

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There needs to be something separating the dual gang pot from the pcb. Like a small slip of cardboard taped into place so the pot doesn’t touch the back of the pcb.

The two threads below should help. If neither of these procedures work then it’s probably a component issue like a wrong resistor value or could possibly be a defective trace on the pcb. It’s most likely something else but my low tide pcb had two bad traces so it’s always possible. I just used a multi meter to check continuity between points until I found the traces that were broken. I’d try the setup procedures first, then check all your resistors if that doesn’t work.


 
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