Refractor - volume problem

[dannoceti]

I recently built a refractor pedal and all seems to be working okay except the volume I really low and the volume pot is not operating correctly. I noticed that on C19, C20, C21, and C22 I accidentally ordered non polarized 1uF electrolytic caps. I was supposed to order polarized ones.  Would this affect the volume pot specifically?

Here are my IC voltages:

IC 1
1: 4.6
2: 4.6
3: 1.24
4: 0
5: 4.5
6: 4.6
7: 4.6
8: 9.16

IC 2
1: 4.6
2: 4.6
3: 4.54
4: -8.66
5: 4.54
6: 4.6
7: 4.6
8: 16.51

IC 3
1: 9.16
2: 4.68
3: 0.0
4: -4.26
5: -8.66
6: 4.31
7: 4.01
8: 9.16






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[dannoceti]

Anyone familiar enough with this schematic to know if C19-22 are directly related to the volume pot and how it functions?


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[RobA]

Anyone familiar enough with this schematic to know if C19-22 are directly related to the volume pot and how it functions?

I haven't built this pedal, but looking at the schematic, those caps are all in the power supply section and won't have a direct interaction with the volume. Using non-polarized caps in there also shouldn't hurt.  But, using caps with too high an ESR can mess with the charge pump. Measure the voltages from the charge pump and you can see if that is a problem. Pin 8 of IC1 will give you the 9V level and pins 8 and 4 of IC2 will give you the +18V and the -9V. Looking at the values you listed, the +18V is a little low, but that could be because of the use of 1N4001's instead of 1N5817's for the diodes. Still, I think it's high enough to not present any problems.

[dannoceti]

Rob thank you for checking this out. Darn, was hoping switching these caps to polarized would help. 

The only other think I can think of is that I forgot to order C6 which was a 390n or .39uf film cap.  I went to frys and all they had was a .34uf Multi Layer, so I just did that. I have a regular .39uf film cap coming on Saturday and will switch it out.


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[dannoceti]

Update:

I replaced the unpolarized caps with polarized electrolytic caps and replaced C6 with a film cap instead of a multilayer and it works great! I also replaced the 392k resistor because for some reason when testing with a multimeter it read zero, just continuity? Anyways it's sounds awesome and is my first klone, really loving it with gain at 9 o'clock  and everything else at 12.


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[dannoceti]

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[RobA]

Update:

I replaced the unpolarized caps with polarized electrolytic caps and replaced C6 with a film cap instead of a multilayer and it works great! I also replaced the 392k resistor because for some reason when testing with a multimeter it read zero, just continuity? Anyways it's sounds awesome and is my first klone, really loving it with gain at 9 o'clock  and everything else at 12.

Congrats on getting it working. That's a strange thing with the 392k resistor (R20?). I don't think it should have registered as 0Ω even in the circuit. Did you happen to measure it after it was out? I suppose there could have been some stray solder around, but that position on the PCB doesn't look very prone to having that issue.