Bass variable freq high pass filter

[johnk]

some of you bass players might be interested in this one. it's a variable high pass filter for cutting the subs out of your signal to help in muddy environments and/or limit excessive low frequency cone excursion. the filter knob is sweepable from 140Hz to 35Hz. it also has a phase reverse switch and a volume control. volume control set to the maximum is at unity gain.

here's the verified vero layout for it:

[Sergio]

Seems great! Thanks John!

[rocket88]

That's awesome john. Do you usually add this to a circuit or have this as a separate pedal?

[johnk]

rocket88 wrote

That's awesome john. Do you usually add this to a circuit or have this as a separate pedal?

as a separate pedal so I can use it with anything. it also works well in an amp's effects loop.
it's the exact same circuit as Fdeck's HPF.

[rocket88]

That's an even better idea. I didn't even think about putting it into the effects loop. I always forget that its there. lol

[cylens]

Thanks for the layout, john!

Just built a stripped down version (no phase switch, no volume pot and fixed frequency) in a 1590LB for a friend of mine, works perfectly!

[AC_FX]

Hi John - is the black circle in the 5th column, 2nd row, indicating a double link?

[johnk]

AC_FX wrote

Hi John - is the black circle in the 5th column, 2nd row, indicating a double link?

yes.

[rudeez]

you're my star johnk, my long time bas playing friend asked me for this about 4 months ago, im sure he will be very happy when i tell him i'll do one for him :D
he had tested version 1 without the volume and phaseswtich so this is even better :)
thanks again!

[Mark SL]

How would we change the circuit to make it a low pass filter?

[AC_FX]

boxed this last night, works great, thanks.

[AC_FX]

John, I'm building another one of these and noticed that the jumper from Source of Q1 is shown in two different locations.  It should jump that Q1 source to the phase switch row, and not to Q2 source, right?

[johnk]

yep. I corrected it on the vero posted above today.