Title link takes you to shots via this auction. Details:
"You are bidding on a keyboard from a estate, this keyboard was played in the 70s and was stored away for the past 20 years. We plugged in the keyboard and all keys work nice including all the lighted buttons and the left and right equalizers, we did try to test most functions however we are not totally familiar with this equipment so we cannot guarantee every function works perfect. The keyboard looks to be well taken care of. It has a case and 4 steel legs that fold up. We would rather this be a local pick up however we can ship this item.
The RMI Harmonic synthesizer offers very unique and characteristic sounds thanks to a special sound generation : additive synthesis.
Harmonic Synthesizer looks like a combo-organ, two sets of 16 harmonics sliders show that this synth is particular to one of the two harmonic generators.
Manufactured by Allen Organ Company
Product : Harmonic Synthesizer
Manufacturer : RMI
Release date : 1974-1976
Country : USA"
Update via Stephen, aka Wavecomputer360 on AH:
"Did you have a closer look at the pictures in the auction? This unit doesn´t have the etched markings around the harmonics sliders, the panel is unmarked. To me it looks very much like one of the original prototypes as the one pictured in contemporary sales ads had no markings, either (and neither did the unit used for the demo LP). It didn´t have a "sync" function, either, but this model here has one. Telling from where it is located I wouldn´t be surprised to learn it used to belong to a former RMI employee (maybe even to Mike Mandel, who knows?). And I´d take any bet that the serial number is lower than 010.
Timbrally, the Harmonic can come up with some rather unusual stuff. It sounds a lot rawer around the edges than e. g. a Kawai K5000 although in theory, it does a very similar thing. There´s a ring and buzz to the Harmonic which goes beyond the audible range, the sine waves are slightly clipped, producing no pure sines but slightly rectified sine-square hybrids. The timbres it can produce are really particular. It excels at spikier tones thanks to its somewhat limited envelope generators. Also, it would have benefitted enormously from a second LFO which would have allowed for more complex modulations of the two generators. Oscillator crossmod or ringmod would have expanded the scope enormously but, alas, there´s nothing along these lines (an external device can do miracles, though). The filter tends to be more like a hi-fi filter, it *does* some filtering but the way the separate outputs for lowpass, bandpass, and highpass interact is somewhat odd (and frankly, it sounds more like 6dB slope, if anything). It doesn´t sound quite as meaty as an ARP, Moog, or early Roland SH filter. An external box (like a Moog VCF pedal) can help a lot. The fun bit is the arpeggiator which can be tricked into doing random stuff, quite funny but unfortunately not designed to be triggered by external devices. RMI quickly withdrew a mod they offered during the first years of production as it seemed to produce a lot of undesired side effects and even rendered some units unplayable. These mods were no longer covered by RMI warranty...
The most extensive use of an RMI Harmonic can be found on Jarre´s original "Oxygene" album from 1976. All the tingly, spiky stuff is the Harmonic, and the second half of Part Five showcases the RMI as a marvellous sequencing tool (multitracked, and certainly played manually on top of some arpeggiator noodlings). Other very nice examples of the Harmonic in use are the albums "Moebius 256 301" and "In Course of Time" by Zanov, from 1977 and 1979, respectively.
As for numbers made, I´d estimate something between 150 and 250 units altogether. Mine has serial number 140, and I know of another one which has serial number 146. Much to my amazement, another Harmonic showed up for sale on evilPay Germany last year (I used to think I owned the only one in Germany). I know about one unit in Germany (mine), one or two in the UK (Aphex Twin is rumoured to own one), two in Australia, two in France (Jarre, and -- maybe -- Zanov?), and maybe a handful in the US.
The KC series of Keyboard Computers are lovely instruments in their own right (I guess Frank Vanaman would second this). I never had a KC-1 but the KC-2 I used to have was very much a proto PPG. I am convinced that Wolfgang Palm knew the KC-2 when he designed his own Wave Computer series of instruments. In contrast to the PPGs the RMI tends to be a lot more polite and well-behaved but it produces a similarly buzzy digital sound. Very rough and at the same time sweet. Timbrally, it´s an entirely different sort of thing, and it´s not terribly useful for all sorts of genres but I used it on the final [´ramp] album "ceasing to exist" (hint, hint) for some ambient textures and loops. I have no idea how many of these were made, mine was serial number 0745, and today it resides in a synthesiser museum in Turkey... I replaced it with a Prophet VS, though, and the VS can do some of the KC-2 timbres amazingly well.
The demo LPs RMI produced for both the Harmonic/KC-1 and the KC-2 don´t do either instrument justice. I for one would never go out and buy any of these after hearing those albums. Definitely not aimed at the experimenting musician, the albums tend to sound rather "campy" and unwillingly funny. I got my KC-2 demo LP through the former German distributor of Allen and RMI instruments (still shrink-wrapped), and I found a copy of the Harmonic demo album on evilPay USA. It was a steal, it was played once (if at all), and it came with the original sales brochures of both the KC-1 and the Harmonic! The previous owner had stuffed them into the album sleeve, and apparently the seller forgot to check the sleeve before shipping the record. The brochures alone are worth a little fortune... at least to me.
My two cents,