Electronics Unit
(photo courtesy Frank Neuperger)

This device (and Telarc record engineering) established a 'gold standard' for audio recording: in its years of production and hundreds of commercial releases, no one ever claimed to hear a difference between its input and output.

The first unit was built in 1977; a total of 18 were constructed through 1981.

   
Top View
(photo courtesy Frank Neuperger)

Two power supplies (one for analog audio, one for digital circuitry) are at the rear. The digital circuitry is the row of cards closest to the power supplies. In the row of analog cards, the four input and four output low-pass filters are visible. In between the filters are four A/D cards (left) and four D/A cards (right).

The cost of parts for this device in 1977 was $21,000. The corresponding Honeywell tape transport cost $25,000.

Circuit boards for the first unit were hand-wired. The backplane (below the circuit boards) was also hand-wired.