Very Quiet Van Pelt (Angry Charlie V4)

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jvo

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I put together a Van Pelt that went together pretty well. When I plugged it in and compared it to the Angry Charles (Angry Charlie V3), it seemed quiet. It is more quiet than clean signal until you turn the volume up to 65% or so.

IMG_9095.jpeg IMG_9096.jpeg

Here is what I have tried:
  • Double checked my component values.
  • Checked for loose solder joints and hit each pad with the soldering iron to make sure no dry joints.
  • Double checked the footswitch connections and resoldered those.
  • I checked the signal path with the probe for any drops along the way and it all sounded good.
  • I replaced the BS170s as maybe they were bad or were damaged by static electricity. Same result.
  • Replaced the 9.1V diode
  • Replaced the R25 100K resistor
  • Replaced the Volume A100K potentiometer

The Bridgold BS170 BS170 values, in VDC, are:

Q1D: 5.43
Q1G: 2.70
Q1S: 2.92

Q2D: 4.66
Q2G: 2.33
Q2S: 0.13

Q3D: 4.85
Q3G: 2.43
Q3S: 0.22

What's suspect to me is that the source on Q1 is higher than the others which is why I replaced the 9.1V diode.

Pretty stumped as to what it could be. Any advice or suggestions would be appreciated.

Thank you in advance.
 
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I see a slightly melted capacitor, did you try replacing it? Also the board could use some cleaning. That’s probably not the issue, but better to have a clean board to rule out accidental shorts.
 
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You mentioned that there is no signal drop at any point in the circuit. I am not sure what exactly Q1's gain should be (I can't figure out the math right now, maybe it's <1 depending on the gain pot position?), but I can tell you that Q2 should have a gain around 30 and Q3 around 15. Since gain is multiplicative, between the gate of Q2 and the drain of Q3, you should have about 450 times the amount of signal. In practice, the FETs will be overdriving so the actual gain will be lower. I would start from verifying substantial gain between those two spots.
 
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giovanni said:
You mentioned that there is no signal drop at any point in the circuit. I am not sure what exactly Q1's gain should be (I can't figure out the math right now, maybe it's <1 depending on the gain pot position?), but I can tell you that Q2 should have a gain around 30 and Q3 around 15. Since gain is multiplicative, between the gate of Q2 and the drain of Q3, you should have about 450 times the amount of signal. In practice, the FETs will be overdriving so the actual gain will be lower. I would start from verifying substantial gain between those two spots.
Click to expand...
It's not a High Gain pedal, it's a JTM45 in a pedal.
This video shows where he has his volume cranked up to get just above Unity & at 10 on the intro.
 
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Thanks for the replies, all. I have a tough time trusting YouTube videos by professionals since who knows what kind of protools they use in post to make it sound professional. That being said, if I put the v3 at volume 10, my neighbors are calling the cops. Knowing that and the comparison between V3 and V4 from the video is helpful. @giovanni since you have a JHS V4, would you please try setting the pedal at noon for everything and telling me if there's a volume drop between clean and dirty? If so, I'll chalk it up as “works as expected” and adjust my expectations accordingly.

Again, thanks to you both for your help.
 
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