Shaping tone?

[wormfooduk]

Hi I've made a overdrive/fuzz along the lines of the bazz fuss , I've run it with a boss eq pedal with a few small cuts in the frequencies that are unwanted. It's sounding really good. What would be the best way to build these tweaks into the fuzz. Ive been using the tonestack calculator to try and copy the curve and add a single tone knob. Is there a better way?

[WGTP]

It depends on what frequencies your wanting to boost or cut.  The circuit requirements will depend on that. 

[Brossman]

If the majority of the frequencies you're adjusting (boost/cut) are in the mid range, try the Big Muff tone stack (if you have duncan TSC, its one of the circuits included, so you can use/edit the schemo there to see Freq. response!)

If you want to adjust it to be darker or brighter, why not have different Caps at the input? you could socket them, or try a 2/3-way switch to give many options.  Bigger cap value = darker, bassy sound - Smaller cap value = brighter, mid/treble sound.

[wormfooduk]

It's a odd one because the frequencies I want to cut are in the high and low mid, but I don't want to cut the frequencies in between. I was think I could use 2 band pass filters somehow? I will see if some combination in the tone stack calculator works first.

[CynicalMan]

I'd use a couple of op amp notch filters:

You might want to make the values of the resistors or capacitors unequal, though. The filter in the schematic is optimized for maximum cut, which might be more harsh than what you want. I'd play around with the values on a breadboard or LTSpice if I were you.

You could also make a fixed version of this, although it would be more complicated:
www.geofex.com/Article_Folders/EQs/paramet.htm#variable_l

[liquids]

What frequencies?

If it's all cut, and all basically in one frequency area, than it could be more or less done passively...or simply, via op amps.

If its select frequencies while other frequencies remain 'flat' between the frequencies you cut, than you got the best way to do it in your hand - a graphic or parametric EQ of some kind.  If you want to be able to combined them, though, so they are both on or off, the bazz fuss is the easy part.     If money and spare are no issue, you could put the two on a dedicated 'looper' that does just that.

[wormfooduk]

im going to try a big muff tone stack with the values i worked out on the tone stack calculator and see how close it is to what i want. If that doesnt work ill have another look at the notch filter idea. I wanted to just have a switch or maybe a tone knob that brings in the eq curve (or close to it) that i worked out on my graphic eq. if the big muff tone stack is close i will just swap out the pot for a set value and put it on a bypass toggle switch so you can go back to stock setting.