Hello all, want to say thnx for all the great work going on here. I built a bjfe sea blue eq a few back and am using it with my acoustic rig. Which works really well! I was wondering if anyone could help me figure out which cap to change to decrease the bass response? Also, I used MPF102's in it and sounds really good. I just want to see if I can get a little more volume out of it? I used Johnk's layout with the mid control. Which works great thnx john. Anyways, thnx for the help and keep on playing!!!!
Of course this is put out of whack to some extent by the inclusion of the mids pot but it will at least show you how altering the component value around the Bass pot will affect the basic response and so give you a good basis to work from.
I've been looking at this schematic, trying to understand how the FETs work. It appears they are in a low current mode of operation, but since this circuit is not intended for much gain (except to drive the EQ), it seems to work. I may simulate this in LTSpice to further my understanding.
It's a lossy passive James tonestack, so there is boost (via the electro's on source) to compensate. You could probably use a mosfet booster circuit in place of the JFETs and get a similar sound without the potential drawbacks of using JFETs.