Akai X-100D

• Track System: 4-track, 2-channel stereo/monaural system with quarter-track stereo recording.

• Tape Speeds: Supports 3 speeds — 1⅞, 3¾, and 7½ inches per second (IPS).

• Maximum Reel Size: 7 inches.

• Heads: 3 heads — erase, record/playback, and cross-field bias head for improved high-frequency fidelity, all made of permalloy.

• Motor: 2-speed hysteresis synchronous motor.

• Equalization: NAB standard with a 3-position equalizer switch.

• Frequency Response:
  7½ IPS: 30 Hz to 23 kHz (±3 dB),
  3¾ IPS: 30 Hz to 15 kHz (±3 dB),
  1⅞ IPS: 30 Hz to 9 kHz (±3 dB).

• Wow and Flutter: Less than 0.15% at 7½ IPS, 0.25% at 3¾ IPS, 0.35% at 1⅞ IPS.

• Signal-to-Noise Ratio: Better than 45 dB.

• Total Harmonic Distortion: Approximately 3%.

• Inputs: Separate level controls for line (50 mV) and microphone (0.5 mV).

• Outputs: 1.23 V line output.

• Semiconductors: Equipped with 11 silicon transistors and 2 diodes.

• Dimensions: 343 x 343 x 230 mm (13½” x 13½” x 9”).

• Weight: Approximately 13.5 kg (30 lbs).

• Additional Features:
  Auto stop/shut off switch.
  Three-digit mechanical tape counter.
  Separate left and right mixable line/mic level controls.
  Optional capstan sleeve and pinch roller for 15 IPS speed compatibility.

• Build: No built-in amplifiers or speakers; solid-state electronics with cross-field head technology for superior sound quality.

The X-100D was one of Akai’s early mid-high fidelity consumer quarter-track stereo tape decks released between 1965-1968, well-regarded for its cross-field bias head design providing enhanced recording quality especially in high frequencies.