Crunch Captain Deluxe low volume?

ragamuffin

ragamuffin

Member
I recently built a Crunch Captain Deluxe and it sounds good and seems to be working but overall volume is low.

With the Mode switch in the middle (classic Crunch Box/high gain) and clipping switch to the right (LED clipping, the lighter clipping option) with Gain at noon I have to nearly max the volume to get unity level. In the heavier clipping setting (to the left) I can hardly reach unity.

Does this sound normal, or is something off?

IMG_2507.jpg
 
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I have not heard or built this drive, nor the one it is similar to. Looking at the schematic, that should have decent volume.

I'd suggest posting pics of the populated board and double checking the component values, while waiting for other member's responses.
 
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I took readings on all the resistors, found some abnormalities:

-R17 and R19 which are supposed to be 220k both read at 133k. Out of spec but maybe ok?
-R1, supposed to be 8m2 and has the right striping, reads at almost nothing; .03ohms. Likely the culprit?
 
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ragamuffin said:
Ok thanks. I do not have an audio probe, I should probably make one sometime

Thanks! It wasn't touching but it was pretty close
Click to expand...

Have you got the ProtoBoard Micro?

ProtoBoard-Micro-2-247x296.jpg


I use mine for breadboarding small circuits, but it gets just as much (or more) use as an audio-probe, and in that guise even more use than my actual audio-probe. (My ProtoBoard Micro also took over my Auditorium Test Platform's duties.)

I just get a female-male breadboard-jumper cable and hook that up to the output and probe away... super simple, super versatile. For me it was money well well-spent.
 
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The clipping switch operation is normal (quieter when silicon diode is enabled), so that's not part of the problem. Where did you source the IC's from? If they are from amazon, that could be your issue. Outside of that, double check your component values and play around with the circuit to try to figure out what is working and what isn't (EQ controls, gain etc)
 
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falco_femoralis said:
The clipping switch operation is normal (quieter when silicon diode is enabled), so that's not part of the problem. Where did you source the IC's from? If they are from amazon, that could be your issue. Outside of that, double check your component values and play around with the circuit to try to figure out what is working and what isn't (EQ controls, gain etc)
Click to expand...
ICs are from Tayda. The controls all seem to do what they're supposed to
 
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Lest do a quick bias check, then inspection.
With power on and no signal, verify these voltages (±0.5V).
IC1-1: 0V
IC1-4: -7V
IC1-7: 0V
IC1-8: +7V
IC2-1: +3.5V
IC2-4: -7V
IC2-7: +3.5V
IC2-8: +13V
Don't bother measuring the other pins because the measurements may not be accurate due to the meter loading the circuit.

Remove the board and do a thorough visual inspection of both sides using light and magnification. My wager is that there is either an incorrect component value (I didn't spot any), a solder splash, a missing or cold solder joint. I built one of these and it goes plenty loud, depending on the setting of the CLIP switch. Check all of the pots too. C19 is melted on top, it may or may not be damaged. The soldering looks pretty good, but I can't see every joint. Look for solder debris hiding under the ICs.

One more thing: disk ceramic caps are noisy and unreliable. They should not be used in a pedal circuit. Depending on availability, use silver mica, film or MLCC. Let's get this pedal working first, then think about replacing those caps.
 
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