The Ampex ATR-100 is a multitrack tape recorder, designed by Ampex Corporation, of Redwood City, California. It was originally released in 1978, and was geared towards the ultra high end studio market, and having been designed specifically as a stereo or quadrophonic (2 or 4 track) mixdown and mastering deck. It has gained a virtually unchallenged reputation in the recording industry and amongst engineers as the most accurate tape recorder ever to be produced.
Key features of the design are the machine's interchangeable headblock system, which allows the ATR-100 to be quickly converted to run either quarter-inch or half-inch magnetic tape. Also, Ampex was the first company to implement a servo-controlled, direct-drive-capstan tape transport, which allows the tape speed and tension to be continuously monitored by a servo relay. The transport consequently has excellent wow and flutter specifications. The ATR-100 also features dual VU meters, or four VU meters in the case of the four track models, and a digital tape timer. An optional remote control is also available.