BSIAB II problem

[BLAMMO]

Hello everyone. I just finished the BSIAB II using the GGG PCB. Everything appears to be correct, and no parts substitutions were used, but the overall volume is extremely low. The voltage readings on the FETs all appear to be close enough to the GGG voltage chart. I'm stumped. Anyone have any suggestions before I start over?

[JimRayden]

After about an hour of stuggling with the circuit and checking for shorts, i usually discover that my guitar volume is almost off. Or the pots on the circuit itself are turned down.

Ok I guess it didn't help you too much.

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Jimbo

[BLAMMO]

checked all that, but your input is appreciated nonetheless.

[mojotron]

Please describe the level of distortion on the signal as well as the relative volume to the bypassed signal, as well as the tone of the signal..

I would suspect a bad solder joint - which, if bad, would go something you could see... - like there is no solder in this one spot. I'm suprised how many times I've missed a hole here or there... and it's a quick check to do this visually.

Also, check the under side of the pot connection, sometimes solder forms a bubble that can short things out on the under side of the terminal to the enclosure.

Also, check that the off-board wiring is correct with a meter from component to terminal.

If all that failed to point out the issue, I would use an audio probe to see what you have on the Q5 gate and half-split the problem from there with the audio probe.

If that failed, you can check the connections between each component with a meter.

I would do all of these before starting over.

[powerplayj]

I assume you adjusted the trim pot?  Again, I'm also touching on the obvious.  My usuall bonehead mistake is when trying out the effect upside down with the back cover off, I manage to plug my guitar into the output jack!  

Do you have anything socketed that might not be in all the way?

[BLAMMO]

Hahahaha I hit all the solder joints with the iron again, and lo and behold! VOLUME!!! Seems a little noisy though, and when the Drive pot is lowered to minimum the volume drops until the signal is gone as well. Is that normal?

[dosmun]

when the Drive pot is lowered to minimum the volume drops until the signal is gone as well. Is that normal?

Yup

Solder joints are the main problem with a lot of builds.  It is the first thing I check.

[mojotron]

when the Drive pot is lowered to minimum the volume drops until the signal is gone as well. Is that normal?

Yup

Solder joints are the main problem with a lot of builds.  It is the first thing I check.

Same here, you can put a 10-50k resistor between ground and the drive pot lug that is connected to ground if you want it to not drop off completely.

The noise is a bit of a problem too, I use a polystyrene cap for the 470pF cap and use a 10pF on the input to take out radio stations signals.

[BLAMMO]

Same here, you can put a 10-50k resistor between ground and the drive pot lug that is connected to ground if you want it to not drop off completely.

The noise is a bit of a problem too, I use a polystyrene cap for the 470pF cap and use a 10pF on the input to take out radio stations signals.

First off, thanks for your help everyone,
I did use a poly cap for the 470pF, but where does that 10pF go on the input?

I gave it a full volume run thru my amp and I got some nasty screeching microphonic feedback sounds with the gain maxed. Otherwise, aside from the noise and high volume screeching, at low amp volumes it sounds pretty rockin. I think ill hit them solder joints on the pots now.