Ampex 900

The Ampex 900 series reel-to-reel tape decks, which include models like the 910 and 960, were professional and consumer tape recorders released around the late 1950s and early 1960s. They represent a transition from tube to solid-state technology with high-quality tape recording and playback capabilities.

Technical Overview of the Ampex 900 Series

• Models:
  Ampex 910: Released 1959-1962, this was a two-speed (3 3/4 and 7 1/2 ips) tape deck with three heads supporting stereo playback but mono recording.
  Ampex 960: An evolution of the 910, physically similar but with full stereo record and playback capabilities. It often came in portable cases with removable speakers and featured bi-directional tape motion (auto reverse).​

• Tape Format and Tracks: 1/4-inch tape with standard stereo two-track half-track format typical of the period. The 960 model allows full stereo recording and playback, while the 910 model only offered stereo playback with mono recording.​

• Tape Speeds: Both models operate at 3 3/4 ips and 7 1/2 ips tape speeds, balancing fidelity and tape duration..​

• Mechanical and Electronic Design: The 900 series integrates vacuum tube electronics (910 model) with reliable mechanical transports. The 960 was often updated with improved features such as higher integration and solid-state components while maintaining rugged, portable design.​

• Features:
  Auto end-of-tape stop to protect tape and equipment.
  Single VU meter and high impedance microphone and line inputs with mixing capability.
  Typically includes matched speaker/amplifier units (e.g., model 2010) with Ampex-designed 8" PM speakers.​

• Physical Dimensions and Weight: Around 17.5" x 15" x 9" (445 x 381 x 229 mm) and weighs approximately 38 lbs (17.3 kg).​

• Audio Performance:
  Frequency response: 50 Hz to 15 kHz (±2 dB at 7 1/2 ips).
  Wow and flutter: <0.25% at 3 3/4 ips; 0.2% at 7 1/2 ips.
  Signal-to-noise ratio: Approx. 50 dB, reflecting professional quality.​

Summary

The Ampex 900 series, especially the 910 and 960 models, are highly regarded vintage reel-to-reel tape decks known for their robust build, reliable stereo recording and playback, and solid audio fidelity. The 910 offered stereo playback with mono recording capabilities, while the 960 advanced to full stereo recording and convenient features like auto reverse. These decks were used in homes, studios, and broadcast environments during their era and remain sought-after by collectors and audiophiles.