Getting more high end out of a circuit?

[tonedawg]

I've been playing with this tone bender variation and while it sounds great, Id love to get more high end out of the "top" control. Is there an easy way to increase the high end range of that control?

[ElectricDruid]

Try reducing C6 to 1n instead.

I haven't looked closely at all the interactions, but changing that cap raises the lowpass frequency by an octave, so it should make it cut less. It will also raise the low end of that control by an octave too, but there isn't much to do about that in this circuit. You could increase the pot value to compensate (so to 50K), but then you'd lose output volume, so you need to proceed carefully.

[mdcmdcmdc]

If memory serves, there's mountains of output volume on tap from that circuit so you could also try swapping the LPF for a HPF, dial out the low end to suit and turn the volume up.

[tonedawg]

If memory serves, there's mountains of output volume on tap from that circuit so you could also try swapping the LPF for a HPF, dial out the low end to suit and turn the volume up.

Is there a way you could show me how to replace the LPF with HPF?

[mdcmdcmdc]

Yeah for sure - hopefully someone who knows what they're actually doing will jump in if this is absolutely wrongheaded...

So the way it's set now, the 25K top pot and 2n2 C6 make a very subtle low pass filter: -3dB at 2800KHz. When I built the black ash it seemed like the knob basically didn't do anything at all. I changed it to be a lower cutoff frequency so it at least had some range...

To make a high pass you need a capacitor in series and a resistor to ground; since that 100uF C5 is already there, you just need to figure out the frequency you want, pick a suitable pot and wire it as a variable resistor to ground. A 2K pot would give you -3dB at ~800Khz, a 5K pot would give you -3dB at ~320KHz. You could adjust C5 to suit as well.

Either way, it's a really good sounding TBMKII.