"Modules Included: 901, 901A, 3-901B, 4-902, 903, 2-904A, 904B, 907A, 4-911, 911A, 921, 951, 960, 961CP, 962CP, 984, 991, custom 994 (3x), 2-CP3A, CP4A, upgraded CP8A
This Custom Moog Modular System 55 has two very unique features: Two 904A low pass filters and both the 901 and 921 series oscillators. Having two 904A's greatly expands the flexibility of the sound engine and the addition of the 921 control oscillator adds functionality while maintaining the richness of the sonically superior 901 series. The system also has an upgraded power supply which helps maintain oscillator stability. This synthesizer was not designed to be looked at or used as a fancy minimoog -it was built to be a complete and complex electronic sound machine. $62,000.00 For show in LA, CA. Serious inquires and buyers only contact: info@aisounddesign.com"
Update via 3P in the comments: "Not a 55. Module placement is different, the Moog module logos are Trumansburg/Williamsburg era. And there are no 921 Series oscillators."
And via Unknown in the comments, there's actually a 921 in the system. Top row to the left of the four channel mixer, pictured here to the left.
Update2 via the seller: "What is meant by 'System 55' is basically a main cab with single tier, rather than a 35 which was just the main cab. "Module placement is different" ie "Custom." Looks like a 921 and there are a lot of RA Moog logos. This system is a unique design; a hybrid of multiple generations. Also note that the 962CP is very rare, most module lists don't seem to mention it."
Update3 via
Brian in the comments: "Likely NOT delivered from the factory that way. It is what it is, but calling it a System 55 is not correct. The 901 oscillators were discontinued in 1972, when the 921's replaced them. At the time, NO ONE felt the 901s were superior in any way (some of us now think differently). I see a mixture of RAMoog (1960s generally) and Moog Music modules there (1972 and later), too.
Again - any customer could order anything from the factory, but it's highly unlikely this was ordered this way; rather it is built from traded in-out components to make a great system. I'd MUCH prefer to have one like this with both sets of oscillators. All the MAJOR synths by major players were not stock catalog versions, but custom rigs for their needs."
Update4: via Moog1P in the comments: " The bottom cabinet looks to be an early 1C configuration. Every component is there, with the blank panels replaced with the 962CP and 961CP. The placement of the two CP3 mixers would have been to the left, under the 901AB bank and under the 901. At some time the system looks to be upgraded with the installed CP961/962 sequencer components, where the CP blanks were removed, and CP3's moved to the right.
Would be an early 1C as this one has the very first Lexan type lighted flip switchs, only seen on late '67, early'68 models. All the correct lexan switches are there, two sets for the oscillators, and a set for the filter, with trigger/envelope routing, making the cabinet a 1C. The 2C would have 3 CP3 mixers, and the 3C would have 4 CP3 mixers with no CP routing switches, as they were on seperate 1U panels for filter and trigger/envelope.
The module placement above is what you would order any way you wanted. Not uncommon to order a 1C with an extra 901C, and to ommit the 905 reverb to add the 904B high pass filter, direct from the factory. Looks like what we have here. The only other addition to the lower cabinet is the 1U blank replaced with 911A trigger delay. And at some time (definitely not Moog), the removal of the Cinch male S-trigger from the 1/2/3 trigger outputs. (Probably done when the CP3's were moved and 961/962CP added.)
The upper cabinet is an add on, possibly at a later time, but could have been part of the original order. At that time the additional 984 quad mixer, envelopes, VCA's were added. The 960 sequencer, probably added much later, when the bottom CP panels were moved. And much later 921 added. Does not look to me to be a unit made from other Moogs, but rather a 1C with a few add-ons. Everything is there from an early 1C with many period correct additions. Very nice unit, only missing the 905 reverb and 956 ribbon controller. Wouldn't take much to undo those questionable mods to restore this to original specs."
