Understanding and using your moogerfooger® MF-102 Ring Modulator
Welcome to the world of moogerfooger® Analog Effects Modules! Your Model MF102 Ring Modulator is a rugged, professional-quality instrument, designed to be equally at home on stage or in the studio. Its great sound and classic effects come from the state-of-the-art all-analog circuitry, designed and built under Bob Moog's personal direction. Your MF-102 is a direct descendent of the original modular Moog™ synthesizers.
GETTING STARTED Here are some simple instructions on how you can quickly plug in and try out your MF102. 1. Unpack your MF-102. You can place it on a table or on the floor. We suggest that you place it on a table while you become familiar with its features. 2. Check that the power adaptor is designed to supply +9 volts and is rated at your country's standard power voltage (120 volts A.C. for the United States and Canada; 100 volts for Japan; and 220 volts A.C. for most other countries).
7. Now set the MF-102 panel controls as follows (See Figure 2): AMOUNT RATE MIX FREQUENCY Left Switch Right Switch 2 6.4 10 250 "Sine Wave" HI Figure 2 - Basic settings for becoming familiar with your MF-102. Press the stomp switch. The BYPASS light will now turn green. Play your instrument. Your instrument's signal is now going through the ring modulator. Listen to how the MF-102 affects the quality of your instrument's tone. You will hear a distinct vibrato.
HOW A RING MODULATOR WORKS Let's start with some definitions. Please read this section carefully, as it will help you to understand the basic ideas underlying ring modulation. Sound is a vibration of the air. The speed of vibration is called the frequency. It is measured in Hertz (Hz). One Hz is one vibration per second. We hear vibrations from 20 Hz to 20,000 Hz. Musical sounds generally have many frequency components. They're called harmonics, or overtones, or partials.
Now we're ready to talk about what a ring modulator is. In electronics, modulation is any process in which one waveform is changed in response to the contour of another waveform. For instance, amplitude modulation is the shaping of the amplitude (strength) of one waveform by the contour of another waveform. The "AM" in "AM Radio" stands for amplitude modulation.
What if the first input signal has many harmonics? In that case, the ring modulator output contains the sum and difference frquencies between all the harmonics of the first input, and the single frequency of the second input. Figures 7 and 8 show what happens when the first input is a 500 Hz square wave and the second input is a 100 Hz sine wave. Figure 7 shows the waveform and spectrum of a 500 Hz square wave. This waveform has only odd harmonics.
To hear the effect of changing the carrier oscillator frequency, first set up your MF-102 as follows: AMOUNT RATE MIX FREQUENCY Left Switch Right Switch 0 (doesn’t matter) 10 30/0.6 (doesn’t matter) LO Connect your instrument and monitor amp to your MF-102, set the stomp switch so the BYPASS light is green, and play a few simple, sustained notes. You will hear your instrument sound with a slow, smooth tremelo. Your instrument will get soft and loud twice for each cycle of the carrier oscillator.
dual-waveform, voltage-controlled oscillator which frequency-modulates the carrier oscillator. This enables you to move the sum and difference frequencies toward and away from each other at speeds from one cycle every ten seconds, to 25 times a second, with either a square wave or a sine-like wave contour. To hear the effect of changing the carrier oscillator frequency, first set up your MF-102 as follows: AMOUNT RATE MIX FREQUENCY Left Switch Right Switch 4 0.1 10 120/2.
Modulator section. The MIX knob crossfades from the direct (unmodulated) signal to the signal from the ring modulator output. You hear only the direct signal when the knob is counterclockwise, and only the ring-modulated signal when the knob is clockwise. You crossfade smoothly from one signal to the other as you turn the knob. The FREQUENCY knob and the LO-HI switch determine the frequency of the carrier oscillator. The FREQUENCY knob has two calibration ranges: 0.6 Hz to 80 Hz, and 30 Hz to 4 kHz.
equivalent specifications. See the Technical Information section on Page 13 for more information on pedal specifications. When you plug an expression pedal into one of the pedal inputs on your MF-102, the pedal adds to the effect of the corresponding control. For example, let’s say that you plug an expression pedal into your MF-102’s MIX input. With the pedal all the way back, the mix of direct and ring-modulated sound is set by the MIX knob.
TECHNICAL INFORMATION NOTE: The following information is intended for use by people who understand analog electronic circuitry and have enough practical experience to interconnect sophisticated electronic equipment correctly. POWER: The MF-102 works satisfactorily on +9 to +15 volts DC and uses about 100 milliamperes of current. If your power adaptor shows up missing or inoperative, you can power your MF-102 from any other power adaptor with a +9 volt or +12 volt rating and with the same power connector.
Or, if you do not plan to use any expression pedals with your MF-102 but would like to apply control voltages to one or more pedal control inputs, you can use patch cords with regular two-conductor (tip-sleeve) phone plugs. These will short out the +5.7 volt supply to the ring contacts. This voltage is current-limited, so you won't burn anything out, - but no pedal will work in any of the pedal control jacks if a tip-sleeve plug is plugged into even one of the pedal jacks.
LIMITED WARRANTY Moog Music warrants that its products will be free from defects in materials or workmanship, and shall conform to specifications current at the time of shipment, for a period of one year from date of purchase. During the one-year period, any defective products will be repaired or replaced, at Moog Music's option, on a return-to-factory basis. This Warranty covers defects that Moog Music determines are no fault of the user.
MF-102 SPECIFICATIONS DESCRIPTION: Analog effects module incorporating three functions: ring modulator, carrier oscillator, and low-frequency modulating oscillator (LFO). FRONT PANEL FEATURES: FREQUENCY rotary control, which varies the carrier frequency over a seven-octave range. RATE rotary control, which varies the LFO's frequency from 0.1 Hz to 25 Hz. LFO AMOUNT rotary control, which adjusts the amount that the LFO output sweeps the carrier oscillator.
