Moog Music MF-101 Lowpass Filter - Manual (Page 8)

CUTOFF knob up. So, a good rule to follow is: when you use an expression pedal, you
set the corresponding knob for the lowest value you want. Then, advancing the pedal
increases that value.
The expression pedal inputs can also be used as control signal inputs. This enables
you to use your MF-101 with virtually any control signal source: modular analog
synthesizers, MIDI-to-CV converters, etc. You will find information on interfacing your MF-
101 with external control signal sources in the Technical Information section on Page
12.
Your MF-101 has one control signal output jack. It is labeled ENV OUT. It may be used
as a control signal source to control other voltage-controlled devices, including other
moogerfooger analog effects modules. The amplitude of the ENV OUT control signal is
independent of the setting of the AMOUNT control or pedal.
A WARNING!
If you turn the RESONANCE knob past "8" , the filter in your MF-101 will oscillate. That is,
it will produce a tone of its own. This is normal for a lowpass filter of this sort. In fact,
synthesists have prized this effect for the past thirty years!
However, you should be aware that it is possible to overheat your speakers if you set
your MF-101 to oscillate and then leave it on a single frequency at high volume for an
extended time. With no pedal connected to the CUTOFF jack, the oscillation frequency
will be between 15 Hz and 12 kHz, depending on the setting of the CUTOFF knob. With
a pedal or external control voltage plugged in to the CUTOFF jack, it is possible to drive
the oscillating frequency up as high as 40 kHz! Some speaker systems, especially
precision studio monitors or audiophile speakers, may be vulnerable to high-volume
steady tones at some frequencies within the MF-101's range,- even frequencies that are
too high or low to be audible!
You can protect your speakers by being aware of your MF-101's output when the
RESONANCE knob is at "8" or above. Switch your MF-101 to BYPASS when you are not
actually playing it.
ANOTHER WARNING!
You'll find that your MF-101 sounds really good. You may be tempted to crank up the
volume so you can really hear it. That's OK, as long as you keep a lid on those high
frequencies (2 kHz and above) that will stress your ears if they're amplified too much.
Like any high quality electronic musical instrument, your MF-101 is capable of
producing a wide range of frequencies. It is up to you to use that frequency range in a
careful and professional manner.