Ampex 350

The Ampex 350 reel-to-reel tape deck, introduced in the early 1950s (around 1953-1956), is a professional, high-fidelity tape recorder designed primarily for studio use with advanced features for its time. It supports tape speeds of 3¾, 7½, and 15 inches per second, with a frequency response up to 15 kHz at the highest speed, providing excellent audio fidelity.

Tape format: ¼ inch tape on 7-inch reels, compatible with NAB 10½ inch reels using suitable reel size adjustments.

• Head configuration: Three permalloy heads arranged for full-track operation, available in full or half track, supporting mono, stereo (350-2P), and three-channel (350-3P) configurations.

• Electronics: Fully tube-based with separate record and playback electronics and heads, enabling off-tape monitoring and precision control in recording and playback circuits.

• Controls: Electrical push-button operation for remote control, including start, stop, fast forward, rewind, record, and tape speed selection plus equalization for various speeds.

• Performance: Signal-to-noise ratio up to 70 dB (half track), wow and flutter below 0.15%, and fast start times achieving full tape speed in about 0.1 seconds.

• Mechanical: Three heavy-duty motors (capstan, take-up, rewind) ensuring steady tape transport with minimal mechanical noise or wow and flutter.

• Dimensions and weight: Console-equipped versions weigh about 168 lbs and measure approximately 48" high x 29" deep x 25" wide; portable and rack-mount versions were available.

The Ampex 350 was notable for its advanced transport design, quick tape speed changes, and the ability to support multichannel recording configurations, reflecting the evolving demands of professional and broadcast studios during the 1950s. Its modular construction also facilitated maintenance and customization. The introduction of electrical push-button controls was a significant step forward for operational reliability and convenience in studio workflows.

In summary, the Ampex 350 combined precision mechanical engineering with flexible electronic designs to deliver a high-performance, versatile reel-to-reel tape recorder that set professional standards for mid-20th-century audio recording.