BSIAB cap question

[snoof]

Am I correct is assuming that if I make C2 larger, it will pass more bass??  Or is C4 the one to change??  The circuit rolls off just a tad too much bass for me as it is now.

http://generalguitargadgets.com/pdf/ggg_bsiab2_sc.pdf

[Alex C]

I would say that increasing the value of C4 would "pass more bass."  This may be undesirable, though, as gain stages are easily muddied by too much bass.  It might be better to tweak the values in the tone section, after the gain stages.   I would think C8 and R7 would be the main ones to tinker with.

There have also been a few threads in the past on C13 and C14.  Here's one.

Hope that helps, and I hope a more qualified individual will follow up/correct my response.   

-Alex

[snoof]

This may be undesirable, though, as gain stages are easily muddied by too much bass.

Good point.  It seems that the RC filters; C12 & R14=97Hz, C8 & R8=19Hz, R7 & C10=170, are pretty much where they need to be (if my math is right) .  So it seems I need to let the bass through at an earlier stage.  Maybe raising R14 would help??  It's a little earlier than the tone stack??

[John Lyons]

The BSIAB has a good amount of bass.
If you tweak around with the tone section you can decrease the treble and mids which will sound as if you have more bass.

Go to duncan's amp page and download the tone stack calculator.
Then play with some vlaues until you get something you like.

John