A phaser is a type of comb filter, so called because its frequency response has several dips and peaks, like the teeth of a comb. As the phaser response sweeps back and forth across the frequency spectrum, the harmonics of the audio input signal are alternately increased and decreased. This produces the classic phaser "whooshing" sound.

What is a 12-Stage Phaser?
The MF-103 produces two comb-filter responses. They are called 6-Stage and 12-Stage, because of the number of phase-shifting circuits that are used internally. The 6-Stage mode has three dips in its frequency response, while the 12-Stage mode has six dips. These two modes have distinctly different sound qualities. In addition, the MF-103 features a variable feedback circuit which increases the resonance, or ‘depth' of the phaser sound.

MPN: MF-103-0001
UPC: 400061950700

- RATE rotary control, which varies LFO's frequency over a 250:1 range.
- AMOUNT rotary control, which adjusts the amount by which the LFO output varies the phaser sweep.
- SWEEP rotary control, which moves the phaser frequency response over a six-octave range.
- RESONANCE rotary control, which adjusts the height and sharpness of the peaks of the phaser frequency response.
- DRIVE rotary control, which adjusts the gain of the audio input to the phaser.
- OUTPUT LEVEL rotary control, which balances the phaser signals with the bypassed signal.
- LO-HI rocker switch, which chooses between the low LFO range (0.01 Hz to 2.5 Hz) and the high LFO range (1.0 Hz to 250 Hz).
- LEVEL, a three-color LED that is used to set the DRIVE control.
- LFO, a LED that indicates the LFO rate.
- BYPASS, a two-color LED that tells whether the phaser is active 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. Input impedance is one megohm.
- AUDIO OUT 1/4" phone jack - -4 dBm nominal output level. +8 dBm absolute maximum output level. Output impedance is 5,000 ohms.
- AUX OUT 1/4" phone jack - -4 dBm nominal output level. +8 dBm absolute maximum output level. Output impedance is 5,000 ohms.
- RATE, AMOUNT, SWEEP, RESONANCE, all of which are stereo 1/4" jacks that accept moogerfooger EP1 (or equivalent) expression pedals, or control voltages from two-circuit or three-circuit 1/4" jacks.
- SWEEP IN - provides a means of applying an external +/- 2.5 volt control signal to the second 6-section phasing circuit, in place of the LFO. Input impedance is 50,000 ohms.
- LFO OUT 1/4" phone jack - delivers the LFO waveform (triangular wave; +/- 2.8 volts) for use by other voltage-controlled devices. Output imedance is 600 ohms.
- +9V POWER INPUT jack - accepts standard 9 volt power adaptors (power adaptor included).
- General 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.