Rat and big muff hpf and lpf

[ironman180]

Hi guys!

I got an idea for a pedal in which I'd put rat and big muff in one enclosure but I'd like to put some sort of high and low pass filter between them. So here's the thing: is it possible to make a filter with single pot (or maybe a dual gang pot) that lets through big muff's low end and rat's mids and high end. For example: when turned all the way counter clockwise only the rat is on, when you turn it clockwise it bleeds big muff's low end through. When the pot is at 12 o'clock position it blends the two eqs and when you start to turn it clockwise from its 12 o'clock position big muff turns on and it bleeds rat's mids and highs through?
I hope I explained that well. 

Thank you all!

[Mark Hammer]

So you want to run them in parallel and blend between them to achieve what you consider as "the best of both worlds"?

[ironman180]

Something like that 

[Mark Hammer]

There are a few ways of doing it.  One is certainly a simple blend control like that used to adjust the treble/bass levels on a Big Muff's Tone control.  Its strength is that it is simple and cheap.  Its weakness is that you don't really eliminate the signal you don't want.  That is, there is always some bass or treble coming through, even when the control is fully in the opposite direction.

A second alternative is what one might call a balance control.  This is frequently used on stereo amps, as well as pedals that seek to provide a wet-only and dry-only setting.  Here is an example, using the MXR Blue Box.

R20 is a 50k linear pot, whose wiper goes to ground.  R16 and R17 are both 56k.  When the Blend pot is at its midpoint, the two signals being blended - fuzz from Q2 and octave-down from Q3 - are each attenuated by the same amount.  The "half" of R20 and 56k resistor each behave like a 75k pot that has been turned down 2/3 of the way.  R16/17 and R20 form a pair of "reciprocal" volume pots: turn one down and you simultaneously turn the other up.

The advantage is that when the pot wiper is fully rotated in one direction - let's say in the direction towards R17 - that signal goes directly to ground, so you don't get to hear  that signal at all.  The other signal is attenuated by about half (56k/50k).

This approach assumes that you're going to start out with two signals that are a decent amplitude, such that there is still plenty of signal left, even after all that attenuation.

Make sense?

[ironman180]

There are a few ways of doing it.  One is certainly a simple blend control like that used to adjust the treble/bass levels on a Big Muff's Tone control.  Its strength is that it is simple and cheap.  Its weakness is that you don't really eliminate the signal you don't want.  That is, there is always some bass or treble coming through, even when the control is fully in the opposite direction.

A second alternative is what one might call a balance control.  This is frequently used on stereo amps, as well as pedals that seek to provide a wet-only and dry-only setting.  Here is an example, using the MXR Blue Box.

R20 is a 50k linear pot, whose wiper goes to ground.  R16 and R17 are both 56k.  When the Blend pot is at its midpoint, the two signals being blended - fuzz from Q2 and octave-down from Q3 - are each attenuated by the same amount.  The "half" of R20 and 56k resistor each behave like a 75k pot that has been turned down 2/3 of the way.  R16/17 and R20 form a pair of "reciprocal" volume pots: turn one down and you simultaneously turn the other up.

The advantage is that when the pot wiper is fully rotated in one direction - let's say in the direction towards R17 - that signal goes directly to ground, so you don't get to hear  that signal at all.  The other signal is attenuated by about half (56k/50k).

This approach assumes that you're going to start out with two signals that are a decent amplitude, such that there is still plenty of signal left, even after all that attenuation.

Make sense?

Thanks Mark! It's a bit clearer now