The ‘Allen Computer Organ’, Ralph Deutsch – Allen Organ Co, USA, 1971

Allen Computer Organ of 1971
Allen 301-3 Digital Computer organ of 1971

The Allen Computer Organ was one of the first commercial digital instruments, developed by Rockwell International (US military technology company) and built by the Allen Organ Co in 1971. The organ used an early form of digital sampling allowing the user to chose pre-set voices or edit and store sounds using an IBM style punch-card system.

The Rockwell/Allen Computer Organ engineering  team with a prototype model.
The Rockwell/Allen Computer Organ engineering team with a prototype model.

The sound itself was generated from MOS (Metal Oxide Silicon) boards. Each MOS board contained 22 LSI (Large Scale Integration) circuit boards (miniaturised photo-etched silicon boards containing thousands of transistors – based on technology developed by Rockwell International for the NASA space missions of the early 70’s) giving a total of 48,000 transistors; unheard of power for the 1970’s.

Publicity photograph demonstrating  the punch-car reader
Publicity photograph demonstrating the punch-car reader
Allen Organ voice data punch cards
Allen Organ voice data punch cards
Allen Computer Organ
Allen Computer Organ


3 thoughts on “The ‘Allen Computer Organ’, Ralph Deutsch – Allen Organ Co, USA, 1971”

  1. Thanks for listing my website as a source. I assume some of your photos came from my site.

    In your video, there is a some misinformation you may want to correct.

    The reason the stop tabs go up and down in several time slots had nothing to do with the speed of reading information from memory. In fact, this was another clever invention in its own right. The idea was to reduce the power requirements in the console. The electromagnets that forced the tabs up and down were (and still are in moveable tab consoles) big power hogs. By phasing the action, they were able to reduce the instantaneous pulse power requirement and therefor reduce the amperage of the console power supply.

    The “gyro” tab did not control a Leslie speaker – because Allen did not use Leslie speakers. Instead, they had their own rotating speaker design, which I think they called a “gyrophonic cabinet.” While a Leslie speaker had a fixed speaker cone and a baffle that spun in front of it, the Allen system placed a set of speakers on a large wooden disk which was rotated. You can tell if your organ still has the original gyrophonic system if you stand next to the speakers. You will hear a clicking sound which comes from commutator brushes that route the signals onto the rotating disk.


  2. Our Parish Church has one of these Allen Card Readers and the speaker wires were cut during a Church renovation and the speakers were disposed of. I have a sound tech connecting a pair of vintage Alec Lansing speakers to it to see if it is playable.

    Would you be able to give any advice on what may need to be replaced or upgraded to make the best of this instrument before we consider an upgrade? or who in the State of Michigan would best be able to service this instrument?

  3. An excellent collection of data on electronic musical instruments from the earliest to recent. However, there is a hole in your listings from 1939 through 1971: it was during this period that Jerome Markowitz pioneered the individually-tunable oscillator; initially with tubes and later with transistors. A minimal model had 96 oscillators with larger models adding ranks of oscillators as pipe organs add pipes. Allen’s 1971 introduction of digital was late in their history with analog oscillator organs already around the globe.

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