MF102 Mix knob going beyond 100% modulation problem [SOLVED]

[CaptainKeytar]

Hey guys,

I just got my MF102 after seeing it at a friend's house and being impressed. The problem is, the MIX knob on my unit seems to do more than crossfade between dry and wet. When I turn it past 4 (or so), it sounds like the modulation signal folds and essentially doubles in frequency. Here's a video of it in action:

http://www.youtube.com/watch?v=Nt7w9vFzIQw

The same thing happens when MIX is all the way down and I use an expression pedal in the MIX input. The "foldover point" seems to change with the intensity of the input signal, though as you can tell from the video, DRIVE is very low and the input signal isn't clipping.

Is this normal?

[Portamental]

Not a problem really, they all do that. Foogers are complex machines, every circuit interacts with the others in sometimes unpredictable ways. You should see that as a plus. Thanks for posting that, trying it and testing allowed me by accident to pretty much nail the sound of the introduction of Wayne by Chantal Kreviachuk, which I never played before. Gonna be playing that all day on my favorite guitar.

Now if someone has a good moogerfooger setup for Crimson and Clover, I would love hear about it.

[SteveD]

That's totally normal - here's why:

The ring modulator produces the sum and difference frequencies of the carrier osc. and the input,

When the carrier is subsonic - say .1Hz, and the input is audible - say 100 Hz,
the sum and difference frequencies are 99.9Hz and 100.1 Hz. You hear it as tremolo - but it it is really the beating of two frequencies (you hear this as a .2 Hz beating).
When you mix in the original tone equally then you have 99.9Hz, 100 Hz and 100.1 Hz mixed together - so the beating sounds like its .1 Hz which is twice as slow (though when they are mixed inequally, then you get some of the extra undulations you hear)

Hope that helps!
SD

[CaptainKeytar]

Awesome, thanks, guys. SteveD, your explanation makes total sense.

For what it's worth: before I'd read SteveD's explanation, I took my MF102 to my friend who had the one I'd played with, and they behaved exactly the same.

The more you know....