|Oscillator||3 VCOs, white/pink noise|
|LFO||Oscillator 3 can function as LFO|
|Synthesis type||Analog Subtractive|
|Filter||24dB/oct, 4-pole lowpass filter
with cutoff, resonance,
ADS envelope generator,
|Attenuator||ADS envelope generator|
using oscillator 3/noise
|Keyboard||44-note, low-note priority|
|Left-hand control||Pitch bend and mod wheels|
The Minimoog is a monophonic analog synthesizer, invented by Bill Hemsath and Robert Moog. It was released in 1970 by R.A. Moog Inc. (Moog Music after 1972), and production was stopped in 1981. It was re-designed by Robert Moog in 2002 and released as Minimoog Voyager.
The Minimoog was designed in response to the use of synthesizers in rock and pop music. Large modular synthesizers were expensive, cumbersome, and delicate, and not ideal for live performance; the Minimoog was designed to include the most important parts of a modular synthesizer in a compact package, without the need for patch cords. It later surpassed this original purpose, however, and became a distinctive and popular instrument in its own right. It remains in demand today, over four decades after its introduction, for its intuitive design and powerful bass and lead sounds.
At its most basic, the Minimoog control panel can be broken up into three sections:
- The signal generators (the three VCOs or voltage-controlled oscillators and pink or white noise)
- The filter (the VCF or voltage-controlled filter)
- The amplifier (the VCA or voltage-controlled amplifier)
The Minimoog is monophonic (only one note can be played at a time) and its three-oscillator design gave it its famous fat sound. Four prototypes were made over the years before a final design was decided upon to release as a commercial product. The Minimoog Model D adapted some of the circuitry (such as the filter section) from earlier modular instruments, but designed other circuitry (such as the oscillators and contour generators) from scratch. To produce a sound, the musician would first choose a sound shape to be generated from the VCO(s) and/or the type of noise (white or pink). The VCO provides a choice of several switchable waveforms:
- triangle wave
- Reverse sawtooth/ramp wave
- Sawtooth/triangle (only in oscillators 1 and 2/sawtooth wave in oscillator 3)
- square wave
- two different width pulse waves
The signals are routed through the mixer to the VCF (voltage-controlled filter), where harmonic content can be modified and resonance added.
The filtered signal is then routed to the voltage-controlled amplifier (VCA), where its contour is shaped by a dedicated ADS (Attack, Decay/Release, sustain) envelope generator. Part of the appeal of this instrument over the early modular Moogs was that the Minimoog required no patch cables; its signal and control voltage path is hard-wired, or "normalled". While this imposed the signal flow limitation outlined above (VCO → VCF → VCA), there are ways to tweak the sound. For example, in reality, the Minimoog has six sound sources. Five of these sound sources pass to a mixer with independent level controls:
- 3 voltage-controlled oscillators (see above)
- A noise generator
- An external line input
And the VCF can itself be made to oscillate, thus providing the Minimoog's sixth sound source.
The voltage-controlled filter (VCF) and voltage-controlled amplifier (VCA) each have their own ADSD envelope generator (or Attack-Decay-Sustain-Decay). Musicians who are familiar with more modern synthesizers might expect the last letter to be R for "Release" (as in ADSR). However, on the Minimoog, the envelopes are ADSD as the Decay setting also sets the time for what's regularly known as Release. In other words, there are three knobs to control 4 sections of the sound (most modern synths have four knobs, one for each section) — a "shortcoming" that doesn't seem to diminish the Minimoog's popularity in any way. There is also a switch above the pitch and modulation wheels to engage the final decay stage as well as a switch for engaging the glide circuit.
The VCF is of transistor ladder type, a design patented by Moog (US 3,475,623). Rumors that Moog had to go to court over the patent seem to be nothing more; 'differences' with ARP at one point were settled amicably.
The output of the third oscillator and/or the noise generator can also be routed to the control voltage inputs of the filter and/or oscillators. The amount of pitch or filter modulation thus realized is controlled by the modulation wheel, which is the right one of the two plastic disks located to the left of the keyboard. In this way, the third oscillator is frequently used as a low-frequency oscillator to control pitch (oscillator modulation) and/or harmonic content (filter cutoff frequency modulation).
The Minimoog can be controlled using its built-in, 44-note keyboard, which is equipped with modulation and pitch-bend wheels or by feeding in an external one-volt-per-octave pitch-control voltage and triggering the envelope generators with an inverted switch trigger (S-Trigger in Moog terminology).
External pitch control does not pass through the glide circuit, nor is it presented to the VCF tracking switches — the external inputs were not designed for external keyboard control. The lowest note played on the keyboard determines the pitch, a condition that is referred to as low-note priority. The envelope generators do not re-trigger unless all notes are lifted before the next note is played, an important characteristic which allows phrasing. The modulation and pitch-bending wheels were an innovation that many instrumentalists found to be extremely playable. The pitch-bend wheel is on the left of the modulation wheel. It is normally kept in the centered position. It is not spring-loaded; the player must return it to the centered position to play in tune. There is a delicate detent mechanism to help the player find the center position tactually. In sharp contrast to later synthesizers that also have pitch-bend wheels, there is no deadband near the center of the wheel's travel; the wheel produces minute changes in pitch no matter how slightly it is moved in either direction. The wheel can therefore be used to introduce slight vibrato or nuance, as well as accurate pitch changes. However, Moog later recommended adding a deadband mod and published this mod in their factory service notes. The detent mechanism can be adjusted somewhat in its strength.
David Borden, an early associate of Moog, has said that the Minimoog "took the synthesizer out of the studio and put it into the concert hall". Jazz composer and bandleader Sun Ra used one of the first Minimoogs, a prototype lent him by Moog in 1969: "We loaned it to him and Sun Ra’s way of working is that when you loan him something you don’t expect to see it back."
Keith Emerson was the first musician to tour with a Minimoog, in 1970, during Emerson, Lake & Palmer's Pictures at an Exhibition shows. Many essential pitch-bending techniques were first demonstrated by him, and many keyboardists learned how to pitch-bend by following his example. He immediately adopted it as one of his main instruments.
Keyboardist Rick Wakeman said of the Minimoog's invention: "For the first time you could go on [stage] and give the guitarist a run for his money...a guitarist would say, 'Oh shoot, he's got a Minimoog', so they're looking for eleven on their volume control - it's the only way they can compete." Wakeman said the instrument "absolutely changed the face of music."
The early sound of post-disco was defined by the use of Minimoog. It became the signature sound of record producer and multi-instrumentalist Kashif who utilized it in works of artists ranging from Evelyn "Champagne" King to Whitney Houston.
Kraftwerk co-founder Ralf Hutter used a Minimoog on the successful concept album Autobahn, and the Minimoog was used extensively on many subsequent albums, including The Man-Machine and Computer World. The characteristic "electronic" yet elegant sound of the Minimoog became an important part of the Kraftwerk sound which in turn inspired an entire generation of electronic musicians.
Due to the design of its 24 dB/octave filter, its three oscillators, and tuning instabilities which tend to keep the oscillators moving against one another, the Minimoog can produce an extremely rich and powerful bass sound. Despite the advent of low-cost digital synthesizers and samplers, the Minimoog remains in high demand with producers and performers of electronic pop and electronic music.
The Minimoog was highly popular in the 1970s and 1980s, and has been used by many artists. For an incomplete list, see List of Moog synthesizer players.
- Various versions of minimoogs
- "Chronology 1953-1993". Moog history. MoogArchives.com.
- Moog patents
- US Patent 3475623 R. A. Moog, Electronic High-pass and Low-pass Filters Employing the Base-to-Emitter Resistance of Bipolar Transistors, issued October 1969 (PDF)
- Trevor Pinch, Frank Trocco, Analog Days: The Invention and Impact of the Moog Synthesizer. Harvard University Press, 2004, p. 263. ISBN 0-674-01617-3
- Franklin Crawford (August 23, 2005). "Robert Moog, Ph.D. '64, inventor of the music synthesizer, dies of brain cancer". Cornell University News Service. Retrieved 4 May 2007.
- Hans Fjellestad (2004). Moog
- Norman, Riley (May 1986). "The Arts >> Music". The Crisis May (The Crisis Publishing Company, Inc.) 93: 10.
- "MiniMoog SN history". The Loads of the Mini. Retrieved 2013-09-15.
There were not only 2 versions of the Minimoog D but 6 ! 1/ For the very first R.A Moog model D (1970) ... 2/ The next ones “D” are still R.A Moog Model, always have discrete VCO (1970) but are cosmetically a little bit different from the first ones. ... 3/ Minimoog D Musonic.(1971) R.A Moog Cie became Musonic Cie when R.A had to merge with Musonic cie. ... 4/ Minimoog D Moog Music (1972). These ones are the “famous” old osc. board but these osc board are not at all the same as the RA & Musonic. ... 5/ Moog perfected the Minimoog by issuing a revised osc. circuit board which gave far improved stability and added a new “buffer board”, which gave better stability. All Mini with serial number greater than 10175 have the newer osc. board.
Early R.A. Moog Model D slightly resembles Model C without modulation wheel, and later R.A. Moog Model D has factory installed white or black name plate.