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Moog MF-101 Moogerfooger Low Pass Filter

Moog MF-101
Moog MF-101
List Price: $299.00
Our Price: $289.00

Availability: Currently Unavailable
Product Code: 9999-08734


Moog MF-101 Moogerfooger Low Pass Filter

The Moog MF-101 Moogerfooger Low Pass Filter, contains the legendary Moog filter as well as an envelope follower for dynamic-controlled filter sweeps. Used with Bass, Guitar, Keys, Samples, or recorded tracks, the MF-101 is ready to be tweaked for classic Moog filter effects.

Moog MF-101 Moogerfooger Low Pass Filter Details

The award-winning MF-101 Lowpass Filter is a direct descendant of the original Moog modular synthesizers. It contains two complete modular functions: a voltage-controlled lowpass filter and an envelope follower. It can be used with any instrument-level to line level-signal.

The moogerfooger filter's control parameters are signal mix, cutoff frequency, resonance amount, and envelope amount. All of the Lowpass Filter's parameters can be controlled with expression pedals or external control voltages as well as by great feeling knobs which beg to be tweaked. Panel switches select filter mode and envelope follower speed. 1/4" jacks are provided for audio input and output, pedal/control inputs and envelope follower output. A heavy-duty, yet smooth-acting bypass switch allows tabletop or foot operation.

A lowpass filter removes high frequencies from a tone. It makes the tone sound more mellow or muted. The lower the Cutoff, the more muted the tone sounds. Imagine a window shade. As it is pulled down, it cuts out the higher light, then the light from the middle of the window, then finally all the light. The MF-101 Lowpass Filter does the same sort of thing to the sound spectrum with its Cutoff Control.

As you turn up the Resonance control, the overtones near the cutoff frequency are boosted. Resonance gives the moogerfooger filter the same classic Moog filter sound as the Minimoog; and Moog modular synthesizers.

The envelope follower tracks the loudness contour (envelope) of a sound, and produces a voltage that follows the dynamics of your playing. Every time you play a note, the envelope voltage goes up and then down. The harder you play, the higher the envelope voltage goes. The envelope follower opens and closes the lowpass filter. Think of the envelope voltage as an invisible hand that turns the CUTOFF knob up and down every time you play a note. Since the envelope follows the dynamics of your instrument's signal, you actually play the filter as you play your instrument.

110 V Power supply is included.

Moog MF-101 Moogerfooger Low Pass Filter Features

  • CUTOFF rotary control, which varies the filter's cutoff frequency over an eight-octave range.
  • RESONANCE rotary control, which varies the shape of the filter's response, from pure lowpass to actual oscillation.
  • ENVELOPE AMOUNT rotary control, which adjusts the amount that the input signal's envelope sweeps the filter cutoff frequency.
  • MIX rotary control, which crossfades continuously from unfiltered to filtered audio.
  • DRIVE rotary control, which adjusts the gain of the audio input.
  • SMOOTH-FAST rocker switch, which chooses between smooth and fast envelope follower response.
  • 2-POLE 4-POLE rocker switch, which chooses between 2-pole (bright) and 4-pole (deep) filter frequency response.
  • LEVEL, a three-color LED that is used to set the DRIVE control.
  • ENV, a LED that indicates the strength of the envelope voltage.
  • BYPASS, a two-color LED that tells whether the filter is on or bypassed.
  • ON/BYPASS, a rugged, smooth-acting "stomp switch."

Jack Panel Features

  • AUDIO IN 1/4" phone jack - accepts any instrument-level or line-level audio signal from -16 dBm to +4 dbm.
  • AUDIO OUT 1/4" phone jack - -4 dBm nominal output level.
  • CUTOFF, RESONANCE, AMOUNT, MIX, all of which are stereo 1/4" jacks that accept moogerfooger EP1 (or equivalent) expression pedals, or control voltages from either two-circuit or three-circuit 1/4" jacks.
  • ENVELOPE OUT jack - delivers the Envelope Control voltage for use by other voltage-controlled devices.
  • +9V POWER INPUT jack - accepts standard 9 volt power adaptors (power adaptor included).

Moog MF-101 Moogerfooger Low Pass Filter Specifications

  • CASE: Black panel with hardwood sides - classic analog appearance.
  • DIMENSIONS: 9" x 6" x 2-1/2"
  • NET WEIGHT: 2 lb
  • SHIPPING WEIGHT: 4 lb, including power adaptor and instruction manual.
  • POWER REQUIREMENTS: 105-125 volt, 5W. 220 volt power adaptor available on special order.

Control Voltage

In electronic music terms, a control voltage is an electric signal that you route to a destination such as a voltage-controlled oscillator, amplifier, or filter (VCO, VCA, or VCF, respectively). You might think of voltage as electrical pressure, which is used to control--or modulate--some aspect in the destination device. When you apply different voltages to a VCO, the oscillator's pitch will vary. Route a control voltage into the frequency cutoff of a lowpass VCF and you can modulate the brightness of the audio signal traveling through the filter. Audio signals passing through a VCA will come out louder the greater the control voltage you pump into the amplifier; lower the control voltage and the signal will get quieter. Even the audio signal itself is an analog voltage.

A control voltage is an analog signal. What's the main difference between analog and digital? While an analog signal is capable of continuous fluctuations, digital data is quantized into discrete steps.

In an analog audio system, fluctuations in voltage are analogous to changes in air pressure in a wind instrument. Parameters such as oscillator pitch and LFO speed are modulated by analog control voltages in an analog synthesizer. Conversely, digital music equipment uses microprocessors to store, retrieve, and manipulate information about sound in the form of numbers, and typically divides potentially continuous fluctuations in value (such as amplitude or pitch) into discrete quantized steps.

The types of control-voltage sources and the destinations to which CV signals can be applied depend on the system you're making music with. If you have any of the Moogerfooger products, you get a good selection of both--and the possibilities increase exponentially when you combine multiple Moogerfoogers. Such a combination makes for an effects-processing system with which you have realtime dynamic control. Include an MF-101 Lowpass Filter or MF-102 Ring Modulator--either of which can serve as an audio source--and you have a functional modular synthesizer.

Let's take a look at the sources and destinations found in a typical modular system, as well as those inherent in all five of the Moogerfoogers, then discuss what the heck you can do with all this fun stuff.

Generic CV Sources and Destinations

Devices that generate control voltages come in numerous shapes and sizes. Prior to the introduction of MIDI, keyboards were designed to output discrete stepped voltages to trigger specific pitches in a VCO. Analog sequencers worked the same way. Play a note on a CV keyboard or advance an analog sequencer by one step, and either device will output a specific, steady-state voltage.

Two of the most creative CV sources in a synthesizer are the envelope generator and low-frequency oscillator (EG and LFO for short). An EG outputs a continuously variable voltage that changes over time. This voltage is typically applied to a VCA or VCF to shape the volume or timbre of a sound; VCO pitch is another potent destination, so you can get programmed pitchbends. EGs range in complexity from a two-stage attack-decay envelope to a multi-stage envelope with independent rate and level parameters for each step and flexible envelope-looping options.

Harness the Power of the Moogerfoogers

What does the term "voltage control" mean to you? If you're only experienced with digital synthesizers, chances are slim you know much about it. In fact, since the introduction of MIDI in 1983, few synthesizers use voltage control beyond the input for a sweep pedal. Such a pedal is typically used to control volume, although some synths allow you to assign a pedal to control parameters such as the portamento rate or filter cutoff frequency.

Such simplicity and inflexibility isn't the case for an analog modular synthesizer, which virtually lives on control voltages. The creation of even a simple sound on a modular takes a handful of patch cords, and dozens of cords are required for complex patches. While that may sound daunting, consider the power and possibilities such a system provides: Many sound developers turn to modular synthesizers to create sonic events and textures that can't be produced any other way, even in a digital environment.

Bob Moog poses with Keith Emerson's modular Moog system--"The World's Most Dangerous Synth"--in August 1999. The multitude of colorful patch cords gives an indication of the number of cords required to set up a complex patch on a modular synthesizer.

With the CP-251 Control Processor and the Moogerfooger line of effects processors--the MF-101 Lowpass Filter, MF-102 Ring Modulator, MF-103 Twelve-Stage Phaser, and MF-104Z Analog Delay--Moog Music has re-introduced the power and flexibility inherent in analog modular synthesizer systems. But before you can realize the potentials, it's best to understand the underlying principles of voltage control.

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