BSIAB2 sounds muffled

[buduranus2]

GGG board. Even with the tone all the way up it sounds like it's got a pillow on top of it. I had tried clipping a lead at C14 which made it brighter but less "brown." So I put it back the way it was. Trying to keep it brown but with much more bite. Also the Contour control doesn't seem to do very much. Any suggestions are greatly appreciated.

[GibsonGM]

Hi Bud, welcome. Can you post some pics of your build?  Board shots, front & back, good enough to see the solder joints etc.

I'd suspect a wrong component value (maybe a cap got switched, so a larger one than you should have is in a 'tone position'?), but we can't tell til we can take a look.  The fact you have sound is a good thing, means it should be easier to track the issue down   

[buduranus2]

Thanks. Appreciate you taking an interest. Since I took the photo I took care of some funky solder joints and dressed a couple of leads to eliminate squealing.

[11-90-an]

Yessir welcome to the forum...

Here are the files/schem, for convenience... http://www.generalguitargadgets.com/effects-projects/distortion/bsiab-2/

Have you adjusted the trimmer properly and set the right voltage?

A picture of the back of the board will also be useful...

[spi]

I assume these are jfet transistors?
What did you use (usually 2n5457 I think)?  Where did you get them? 

[buduranus2]

Yeah, they're JFETs. Came with the unit. I'm assuming they're matched.

[buduranus2]

Yessir welcome to the forum...

Here are the files/schem, for convenience... http://www.generalguitargadgets.com/effects-projects/distortion/bsiab-2/

Have you adjusted the trimmer properly and set the right voltage?

A picture of the back of the board will also be useful...

The trim pot's set correctly. Voltage is correct although a friend who's much more knowledgeable says that because of the variability among JFETs there's no single "correct" bias for the pedal.

[aron]

You can quickly debug this with the audio probe in the debugging link. Test at the input of the effect, then work your way through the effect, listening after each stage. At some point, the signal will be muffled. You can also eyeball the circuit like everyone else said. Since the tone pot is seemingly not working properly, you can look carefully at the components there.  Listen at Q1, Q3, Q5, C9 etc... Are you sure C1 is a 250pf?

[duck_arse]

please measure the resistance of R10.

[buduranus2]

OK. What value am I looking for?

[GibsonGM]

OK. What value am I looking for?

The value that it is    Just measure R either side of it - to ensure it's not the wrong value R that belongs in that spot.

[willienillie]

Yeah that's an unusual situation, depending which direction you read the bands it could be 120 or 10K.  If it came with a kit, it could have been mixed up with a 10K, and you might have wrong resistors in two places.

[duck_arse]

OK. What value am I looking for?

not looking for, looking at. looking at the meter display, tell us what is showing thereon. giving hints isn't helpful.

please.