Hello all!
I have a Low Tide Modulator that doesn't seem to be passing any "wet" signal through the MN3207 BBD. I do get the "dry" signal through that doesn't pass through the BBD when the pedal is engaged.
I suspect the root of the problem is the cheap MN3207s that I found via Ebay and decided to try. Unfortunately don't have any known good ones with which to compare. However, with the voltages I'm seeing at the output of the BBDs lead me to believe they are not good.
I'm disappointed that the schematic doesn't seem to be included in the build docs for this yet. If it were, I feel I could be more self sufficient with troubleshooting this, but I unfortunately don't have the pedal background to know where to go from here. Any insights from you guys are much appreciated. (I am an EE, don't have much pedal building experience. A couple of overdrives prior to this one).
In more detail:
I have a Low Tide Modulator that doesn't seem to be passing any "wet" signal through the MN3207 BBD. I do get the "dry" signal through that doesn't pass through the BBD when the pedal is engaged.
I suspect the root of the problem is the cheap MN3207s that I found via Ebay and decided to try. Unfortunately don't have any known good ones with which to compare. However, with the voltages I'm seeing at the output of the BBDs lead me to believe they are not good.
I'm disappointed that the schematic doesn't seem to be included in the build docs for this yet. If it were, I feel I could be more self sufficient with troubleshooting this, but I unfortunately don't have the pedal background to know where to go from here. Any insights from you guys are much appreciated. (I am an EE, don't have much pedal building experience. A couple of overdrives prior to this one).
In more detail:
- Pedal bypassed works as expected
- LED turns on/off with bypass as expected
- Volume/mix control works when pedal is engaged. With mix low, I can hear the "dry" signal come through as expected. Turning up mix fades out the dry signal, but there is no BBD'd signal coming through.
- Voltages as measured by a DMM are attached as a CSV/text file, voltages measured at ICs and transistor nodes attached.
- Knobs when these measurements were taken were as follows:
- Rate max
- Damp min
- Depth ~70%
- LPG max
- Mix Max
- Volume ~50%
- Gate ~50%
- Bias ~50%
- The outputs of the BBD measure near GND, which unless I'm misunderstanding how the BBD functions is not correct. I've verified there is not a low impedance path to GND from those pins. I would have expected to get a voltages similar to the sampled input signal voltage here if I understand what this should be doing.
- I unfortunately don't have on hand an audio probe nor cable I can cannibalize to make one. I'm making enough pedals now though that if I need to, it's probably worthwhile to do so if I'm misunderstanding what the BBD
- Knobs when these measurements were taken were as follows: