The Lowpass Filter Catch-22

[vaylor]

If you are using both the Lowpass Filter and distortion, there is an built-in Catch-22. If you situate the Lowpass Filter before the distortion / fuzz, the effect of the MF is almost entirely obfuscated. If, however, you place the distortion before the Lowpass Filter, the signal coming to the MF is so compressed that the envelope function is almost completely useless.

Has anyone solved this? Is is possible, for example, the capture the envelope using the CP-251 or something else pre-distortion and pipe in into the envelope in on the Lowpass Filter post-distortion?

[bunnyman]

Presumably, you'd want to filter the distorted signal. As you've discovered, a severely distorted signal doesn't have much of an envelope (just off or full on), thereby rendering the envelope follower function fairly useless. I'd recommend getting a Moog control pedal and using your 101 more like a traditional wah (albeit w/ much more range/control)...

-a bunny

[hieronymous]

Or, get another lowpass filter - you can use the envelope in the MF-101 even if the effect is off - put that first (but off) and use the envelope for the first one to control the second one that is after your distortion:

instrument --> MF-101 #1 (off) --> distortion --> MF-101 #2 (on)

with the envelope out in MF-101 #1 connected to frequency in MF-101 #2

[vaylor]

I have a CP-201, and two of its 4 outputs are going to the Lowpass Filter. One goes to envelope amount and the other goes to cutoff freq. This way, with the envelope up and the freq. down it acts as a standard envelop filter, but with the envelope down I can use the expression pedal for wah.

One thing that may solve the issue would be the ability to use a secondary audio signal to control the envelope. I've seen another post about this. I could pretty easily feed a clean signal to that secondary input and maintain the remaining chain.

[varice]

Or, if you don’t want to get a second MF-101 filter, you could get a Freq Box and use the envelope follower output from it to control your filter cutoff.

Another option would be to modify your filter so that you can have a separate (in your case, a pre-distortion) input for the envelope follower. That mod is described here:

http://www.moogmusic.com/forum/viewtopic.php?t=9020

If you or your local tech can't do this mod, contact Moog. They would probably be more than happy to do this custom mod for you.

[vaylor]

Fantastic suggestions, Varice. Can't decide which sounds like more fun: having an excuse to crack open my 101 or having an excuse to buy a FreqBox.

[MBlom]

Here´s a way that doesn´t need a mod or another pedal. Try connecting env-out with amount-in (or for an even bigger effect cut-off-in) on the MF-101, and switch to smooth. This enhances the envelope effect, even if the amount knob is on ten. You could even say it exaggerates it because the amount effect then takes a jump to 20 or so. Just tried it with bass and a Big Muff and I got quite a large cut-off sweep this way, and almost nothing without the cord between env-out and amt-in.

[varice]

Here´s a way that doesn´t need a mod or another pedal. Try connecting env-out with amount-in (or for an even bigger effect cut-off-in) on the MF-101, and switch to smooth. This enhances the envelope effect, even if the amount knob is on ten. You could even say it exaggerates it because the amount effect then takes a jump to 20 or so. Just tried it with bass and a Big Muff and I got quite a large cut-off sweep this way, and almost nothing without the cord between env-out and amt-in.

That's a good tip - Env Out to Cutoff In along with the Envelope Amount knob at max should about double the envelope follower effect. That could be enough. But, in cases with high overdrive distortion that results in amplitude compression, it will still be necessary to split the clean signal for the envelope follower.