Ic voltage issue/volume issue on bluesbreaker clone

[snow123]

Im building a bluesbreaker rn, And the voltage on p3 is about 2 volts too low, And the volume is super low when the circuit is bypassed, and the volume gets even lower when the circuit is turned on. and idk what the issue is at this point, im thinking something is wrong in the power stage but idk.

Here's my soldering and stuff:


















heres the layout im using:



and the schematic the layout is based on:
http://www.generalguitargadgets.com/pdf/ggg_mbb_orig_sc.pdf

[snow123]

and i swapped out the footswitch to see if that was the issue, and it wasnt 'cause the issue is still present with the new footswitch.

[snow123]

wait no, the ic voltage fluctuation is based on what battery im using, i just realized the battery i was using had 8.2v, and i just used a batt with 8.9v and the ic voltages went back up..
heres the current ic voltages anyways lol

IC 1:

P1 = 4.1
P2 = 4.2
P3 = 2.0, 2.1
P4 = 0.0
P5 = 4.1
P6 = 4.2
P7 = 4.1
P8 = 8.3

[idy]

OK, volume low in bypass means you have problems much simpler, like a loose ground on a jack or something. Until bypass is good you don't need to worry about the board....

It looks like the IC is functioning. The low voltage on pin 3 is probably your meter loading it. It *must* be 4.1 or so, because otherwise pins 2 and 1 would be lower too. It is unusual for a meter to load that much though. If you had two meters you would be able to check pins 1 or 2 while you are measuring pin 3. (If this theory is true, I think the other two pins would "dip" when you measure pin 3.)

Nothing suggests a problem in the power supply. Double check grounds jacks and footswitch. Get bypass working. Then if there is still a problem start signal probing.

[snow123]

OK, volume low in bypass means you have problems much simpler, like a loose ground on a jack or something. Until bypass is good you don't need to worry about the board....

It looks like the IC is functioning. The low voltage on pin 3 is probably your meter loading it. It *must* be 4.1 or so, because otherwise pins 2 and 1 would be lower too. It is unusual for a meter to load that much though. If you had two meters you would be able to check pins 1 or 2 while you are measuring pin 3. (If this theory is true, I think the other two pins would "dip" when you measure pin 3.)

Nothing suggests a problem in the power supply. Double check grounds jacks and footswitch. Get bypass working. Then if there is still a problem start signal probing.

i just fixed the bypass, but theres still a big volume drop when the circuit is on.

[idy]

I would check each "cut" in the copper for continuity and scrape the spaces between  traces with an exact-o knife. One tiny short and...nada.

Still trouble I would signal probe. Just a cap on the hot of an instrument cable and an alligator clip on the ground/shield. Clip to ground, plug into a (tiny, not valuable) amp. I usually use a looper pedal because it's hard to strum and probe.

Where does the sound die? Is it making it to pin 3? how about pin 5?

[snow123]

wait i just realized i took out the 220n ceramic cap, 'cause mine just say ".22" and i wasnt sure if it was the right value or not.

[snow123]

This is what the cap says on it

[idy]

That would do it... That is 22 pico farad, 10,000 times smaller than what you need! I can't see it on your board, but I do see how the layout used the graphic for a ceramic cap because the film cap wouldn't fit (without bending the leads.)

[snow123]

yea, i just put it in the circuit and it created a high pitched feedbacking noise when i probed it.

[snow123]

and i just replaced it with a 220nf mylar cap (i dont have any 220n ceramics) and theres still that really big volume drop.

[snow123]

and i just replaced it with a 220nf mylar cap (i dont have any 220n ceramics) and theres still that really big volume drop.

and, i realized i desoldered something, and i just resoldered that thing, and the pedal works now.

[antonis]

@snow123: Plz (and I mean PLEASE..!!) tell us when you are ready for suggestions/comments..!!
(make yourself sure that you won't post anything in between other people answers..)

[Steben]

and i just replaced it with a 220nf mylar cap (i dont have any 220n ceramics) and theres still that really big volume drop.

and, i realized i desoldered something, and i just resoldered that thing, and the pedal works now.

And happy now with the bluesbreaker? 
Is it the high gain version? EDIT: seen the lay out... looks that way