Author Topic: Issues with Glam Chorus Vero Build  (Read 138 times)

Fatknuckle

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Issues with Glam Chorus Vero Build
« on: September 14, 2022, 05:16:08 AM »
Hello:
I have a Glam Chorus I am building on Vero Board per the FX Blogspot layout for the MB design.  Second build for this pedal, first one works well, although there may be some differences from the layout I am using now.  I have been over the board verifying components, placement, continuity, fixing some errant solder traces, cleaned groves between rows, checked links and cuts, checked voltages, probed with an audio probe, etc., changed several chips out (both PT and Op Amp).

Originally I had chorus upon first fire-up for a few minutes, then lost chorus but had straight signal through.  After may last cleaning and run-through, I have no audio output, just bypass through my test rig.  I hear a faint oscillating tone on several components off pin 16 when probing voltages.  LED 1 also pulses, with a voltage of 1.83.  LED2 has 4.18v.  Voltages on PT seem steady and in line.  Regulator is working, and JFET is biased around 5.5, adjusts as needed.

Voltages are as follows:
PT2399 Pins
1  5.02
2  2.50
3  0
4  0
5  2.80
6  2.26
7  1.86
8  0.77
9  through 16  2.51

TL062 voltages, with the exception of pin 4 (0), are all oscillating between 4.43 and 5.00, give or take.
I have tried a TL072 with no change.
I suspect the issue is not the PT2399 and is some thing between the Op amp and out.  More checking and probing this evening.


Fatknuckle

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Re: Issues with Glam Chorus Vero Build
« Reply #1 on: September 14, 2022, 08:18:54 AM »
Vero Layout

Fatknuckle

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Re: Issues with Glam Chorus Vero Build
« Reply #2 on: September 19, 2022, 05:11:28 AM »
Was just a misplaced resistor to the op amp.  Crazy how many times you can look at something and not see it.