MOOG MICROMOOG with New Power Supply

via this auction
"The MICROMOOG is a monophonic analog synthesizer produced by Moog from 1975-1979. Designed by Robert Moog and Jim Scott as a scaled-down version of the MINIMOOG. Incredibly, it has several features that the MINIMOOG doesn't (far more extensive modulation routing, ribbon controller, accessory power, & more). What does the MINIMOOG have that the MICROMOOG doesn't? Three VCO's. But in actuality, since the MINIMOOG doesn't have an LFO, one usually uses two of its VCO's for voice generation, and the third as a LFO for modulation.

Well, the MICROMOOG has an LFO, and a VCO with a doubling circuit, which controllably adds an octave or two below the main VCO pitch. Result? The sound of two VCO's and an LFO. Just like the MINIMOOG. There have been those who claim the MICRO doesn't sound as fat on low frequencies. The mod was installed that supposedly improves this. It's bogus, at least on this particular instrument. This instrument sounds very rich and full, and was directly, side-by-side, compared to a MINI. There's a very, very slight *difference* but neither is *superior* so the mod was removed and this instrument was restored to original.


Take a look at the condition of this extraordinary instrument from 1978 (near the end of production, so it is one of the more stable instruments)...

Time-Calibrated Envelope (Contour) Controls. BOTH positive and negative contour on the VCF. VERY WELL PLANNED switches afford an unusual amount of control. Notice the "Open System Inputs / Outputs" legend.

Here's where one sees great differences between the approaches of ARP and MOOG. MOOG is *musically useful* in addition to being extremely experimentally oriented - witness the calibrated, instantly accessible 5 OCTAVE range controls. The ability to instantly convert the VCO into an extremely WIDE RANGE oscillator, sweeping the entirety of audible frequencies, and then some. Then there's the MOOG exclusive WAVEFORMS (that cross between a sawtooth and square, which is modulatable).

SECOND ROW: First there's that LFO (Low Frequency Oscillator) for incredibly rich slow sweeps, all the way up to musical vibrato, and beyond. And there's the GLIDE (also known as PORTAMENTO) control, for that eerie, human-voice-like quality that is unmistakable.

BUT the BEST is that MODULATION section! Take a look at all the routings! SAMPLE AND HOLD (NOT on MINIMOOG) and more.

BELOW you see the original wimpy power supply. Regulation is with barely heat-sunk TO-220s. Very marginal. AC line variations, spikes, temperature, continued operation, etc. can result in undesired voltage instability. This is the weak link in a MICROMOOG.

THE REMEDY: an Electronic Music Engineer with 40 years experience expertly removed the original supply and replaced it with what you see below. A VAST IMPROVEMENT in several ways. Look at the difference in the size of the filter capacitors - cleaner DC improves the MICROMOOG's sound and consistency in several ways. LOOK at the TO-3 sized REGULATORS. Huge difference in current capability, and thus increased stability, over the wimpy original TO 220s. The DUAL TO-3s are attached to a MASSIVE HEAT SINK under the board. No stress on an already very conservative design. Also the prone-to-failure, almost impossible to find IC in the original design was replaced with TWO independent regulators with TRIMMER POTENTIOMETERs affording adjustment for variations in circuit componentry over time. You're set for a much longer time than the original design.

OUTPUTS - a normal -10dbM, and a VERY STRONG +12 dbM. S-trigger (MOOG's system - convertible), Scalable KEYBOARD CV Out, and BIPOLAR ACCESSORY OUTPUT (originally marked as only being capable of a wimpy 50ma. With the IMPROVED power supply, it is safe to draw at least 200ma from this socket).

Direct AUDIO INPUT so you can use the FILTERS, etc. MODULATION Control Voltage Input, AND SEPERATE VCO and VCF CV inputs. S-Trigger for gating events.

BIRTH CERTIFICATE. 6/5/78. Or 5-25, if the upper initials are the actual birth, and the lower is inspection. That, I don't know. But we do know she's 33 years old.

REAR PANEL has numerous ACCESS PORTS for calibration and adjustments. Some of these you really don't want to touch unless you know what you're doing. Others, such as the "EMPHASIS" tuning, allows changing the character of the instrument's voice quite a bit.


Update via suitandtieguy in the comments: "the filter modification is _not_ bogus. i heard a significant difference when i performed Calaroso's suggested circuit improvement as listed here"