Realistic Synthesizer by Moog Music Concertmate MG-1 Radio Shack Realistic Synthesizer by Moog Music Concertmate MG-1 Model 42-4000 Serial No. 17 813 The Realistic Concertmate MG-1 is an analog synthesizer manufactured by Moog Music. Though built by Moog, it was distributed by Radio Shack under their "Realistic brand" name because it was produced without a number of standard Moog features, such as pitch and modulation wheels, switch covers and a handful of other minor parts. This cost cutting was aimed at achieving a lower price for the toy market. The synthesizer even featured a pair of loop-through RCA ports with which to pump in the radio or one's favorite records, which would then be outputted along with the owner's live synthesized leads overtop of their favorite recordings. It is somewhat similar to the Moog Liberation in that it has the following features: Two oscillators with sync & detune, one producing either a Square or Sawtooth waveform, with the other producing either a Pulse or Sawtooth waveform. One low pass filter/VCF, that can use the envelope generator, has limited keyboard tracking, and is capable of self oscillation. Limited envelope generator with variable attack and release, and a switchable sustain (no decay). Oscillator 2 can be tuned independently or synced to oscillator 1. Noise generator. Ring modulator (called "Bell Tone"). Polyphonic oscillator. This oscillator is routed through the filter, but not through the envelope generator or LFO. LFO that can modulate the oscillators and the filter using a triangle, square or random waveform Portamento (called "Glide") External Control inputs for pre-MIDI CV/Gate. The polyphony features of this synth are of particular interest, as it was a rare feature at the time it was released. The polyphony section is independently tunable, and acts as a third oscillator, sounding like a square wave (described as a "cheesy organ sound" by some). All of the sound-generating features come together in a mixer, allowing the levels the monophonic oscillators, noise, ring modulation and polyphony to be adjusted independently. Since the polyphony section is independently tunable, it can function as a rudimentary third oscillator, allowing the user to create more complex tones than on similar 2-oscillator synths. Additionally, the synthesizer's features aren't labeled using the standard synthesizer nomenclature, instead using more "laymen friendly" terms such as "Tone Source" for the oscillators, "Contour" for the envelope and "Rise Time" for the Attack Time. Still, this synthesizer is sought-after as an inexpensive way to get the famed "Moog Bass" sounds. It is also somewhat infamous in analog synth circles for having black polyurethane foam insulating the interior which did not keep well over time, turning into a black sludge which clogs the various moving parts in the synth (so much so that entire replacement switches and faders can be bought on eBay, specifically for this synth). This MG-1 is in excellent working condition, but is being sold as-is.  The original box and manuals are long gone, but I will send a PDF of the user and service manuals for this model that I found online if requested.  I will pack the unit well, and shipping insurance in the amount of the final price will be included to ensure the unit arrives in the great condition it is in now.