From the Bob Moog Foundation Archives, in an ongoing effort to share the breadth of historic information we are honored to preserve, we present our next unveiling of 15 original schematics, some hand-drawn by Bob himself. View all our schematics on our main schematics page here.

From our first unveiling, in August 2014:

The schematic shows the path of electricity, the components it will pass through, and the layout of those components. But it also demonstrates the aesthetic of the artist and the structural beauty of the design. This strange duality embodies the nature of the schematic.

Bob’s creativity, his spirit, his vision, and his meticulous nature are reflected in the schematics he created, and those created from his work. They are a documentation of the history and progression of his innovation in an artistic and beautiful format.

The Bob Moog Foundation is committed to the preservation of Bob’s legacy through these incredible schematics and mechanical drawings, and is in the process of amassing an incredible array of these documents for this process.

We are progressively sharing schematics in our archive for your examination, learning, and enjoyment.

The archival process required to insure that these documents can be properly shared is very detailed, process-oriented, and thus requires copious time and resources. Please consider donating here to assist us so that we can continue to preserve and share our vast collection.

Post a comment if you have any further information about the people, devices, or rich history of these documents!

Click any schematic to see a larger version.

Presented in chronological order:

1. July 17, 1964: Capacitance Actuated Relay

This was hand-drawn by Bob himself using the initials “B.S.,” his incognito term used to hide the fact that R.A. Moog Co. was a one-man operation.

A theremin is “capacitance actuated” in that the capacity of your hands affects the frequency of the sound, or the amplitude of the sound it creates. However, this is a relay … which is to say that capacitance triggers something. What the heck was Bob up to here?

While there isn’t a lot of information about this particular schematic that has been revealed yet, we believe it may be related to a special collaboration that came a year later (see schematic #4 below).

2. July 28, 1964: Modular Prototype Power Supply

If you’ll look at the date of this schematic, you’ll see that it existed before Bob even showed his initial modules at the AES convention in October 1964. This is a power supply for the original device made for Herb Deutsch. If you compare it to the 910 schematic below, you’ll see that these are two quite different power supplies.

This document is of incredible historic importance, as it is one of the first Moog synthesizer power source designs. We are honored to steward, preserve, and share it with you.

3. March 8, 1965: 910 Power Supply Schematic

The least glamorous of the 900 series: the power supply. However, this particular schematic is exciting because of its age. Drawn this early in 1965, it is probably the initial design for the modular power source.

Drawn by our friend “B.S.” and approved by “R. Moog,” this is another particularly interesting and historic schematic we are honored to preserve and share.

4. March 16, 1965: Renfer Capacitance Relay Oscillator Board

Composer John Cage (with David Tudor and Gordon Mumma) collaborated with choreographer Merce Cunningham to create Variations V, a combination music/dance/technology piece in 1965. In this piece, the movements of dancers in proximity to technology triggered sound samples in an integration of music, dance, and real-time composition.

The technology was comprised of some light-sensitive devices created by Bell Labs scientist Billy Klüver along with 12 capacitance-sensing antennas by none other than Bob Moog. This schematic is likely associated with the creation of this technology.

Also included are some notes Bob took in regard to the design and improvement of the device used in the performance.

5. July 25, 1966: 901B Oscillator Schematic

Our previous schematics page contains a 1969 schematic (#12)  marked “12. 901-B Oscillator Revision”, which may well be a revision to this particular design. Compare the two and see if you can spot the differences!

This schematic is relatively early (drawn in 1966), and is for the design of the 901B oscillator module. Engineer “P.Y.” has taken a bit of creative liberty with the spelling of “schematic.”

6. December 12, 1966: 904-B Voltage Controlled High Pass Filter

In regard to Moog filters, you hear a lot about the 904-A, the celebrated Low Pass Filter. But many forget–or don’t know–that the Moog modular made great use of both a low pass filter AND a high pass filter.

Above is a schematic for the high pass filter. When used in conjunction with the low pass filter, it made a very pleasant-sounding band pass filter.

This was drawn up by Bob Moog as “B.S.,” but you’ll note that it was not approved by R. Moog.

7. March 9, 1967: Random Generator

Here is a hand-drawn schematic by Bob for a “random generator.” This is likely the precursor to the 903 “White Sound Source” below.

8. April 27, 1970: 903A Random Signal Generator Circuit Trace Layout

The 903 module was an early “White Sound Source” module that provided white noise. This expanded version with an updated name and number provided two outputs of white noise and two outputs of “pink noise” (which has more of an emphasis on lower frequencies), making it a “darker” sort of white noise.

This document not only shows the circuit traces but but also has the components written in in pencil, providing a functional portrayal of the module.

9. April 10, 1968: Synthesizer III P System Layout

1968 was the year that the Moog Synthesizer Systems expanded into their console ( C ) and portable ( P ) designations. This system, a “III (the largest) P,” is in portable cases.

Note the relatively uncommon R.A. Moog 991 Filter and Attenuator module at the top of the first case.

10. March 18, 1969: Synthesizer 1P layout

The above drawing is a layout of the Synthesizer 1 P, a smaller system with the “p” designation for a portable case. In the drawing, we can see that the optional 960 sequencer is present, but the 961 Sequencer Interface is not.

Also above is a picture of the 1 P. All of the modules are similar except for our friend the 903, which is present in the drawing of the 1969 system, but is replaced by the 903A in the 1972 photograph. Also, both the 960 and 961 are present in the photograph.

11. August 12, 1969: Performance Console

It wasn’t all resistors and printed circuit boards. R.A. Moog Co. also produced cabinets and stands. Here is a mechanical drawing of the “Performance Console,” a three-tiered wooden structure to hold two keyboards and a modular system.

But more than that, do you know what came a couple of weeks after this? A performance in need of several “performance consoles”: the August 28, 1969 historic “Jazz in the Garden” performance at the Museum of Modern Art. If you’ll look in the photo, you can see three performance consoles similar to this design.

12. May 21, 1970: 902 Voltage Controlled Amp Circuit Trace Layout

Above is the circuit trace layout of the latest version of the 902 amp module from 1970. Like the 903A circuit trace layout, this document includes the components written in pencil.

13. December 14, 1972: Cable Assembly Percussion Controller

Above is a schematic/mechanical drawing of the connector cable for an 1130 percussion controller.

14. January 14, 1982: Digital Sequential Controller Control Board Schematic

Above is a control board schematic for the Moog Digital Sequencer. At some point we’ll post pictures of that device, as we have one in our archives. But for now, examination of this schematic image shows some of the functionality options of the device.

15. February 1982: Final Assembly Digital Sequential Controller

This schematic shows the appearance of the Moog Digital Sequencer as well as how it was constructed. This design was “released for production,” but, sadly, commercial production never happened.

View all our schematics on our main schematics page here.

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