Akai X-150D

• Track System: 4-track, 2-channel stereo/monaural quarter-track system with Akai's cross-field bias head technology

• Tape Speeds: 1⅞, 3¾, and 7½ inches per second (IPS), with optional 15 IPS using larger capstan sleeve and smaller pinch roller

• Maximum Reel Size: Supports up to 7-inch reels

• Heads: Three heads — erase, record/playback, and separate cross-field bias head made of permalloy, which improves high-frequency fidelity

• Motors: Single hysteresis synchronous 2-speed motor with removable capstan sleeve to achieve three speeds

• Frequency Response:
  7½ IPS: 30 Hz to 23 kHz (±3 dB),
  3¾ IPS: 30 Hz to 18 kHz,
  1⅞ IPS: 30 Hz to 9 kHz

• Wow and Flutter: Less than 0.12% RMS at 7½ IPS

• Signal-to-Noise Ratio: Better than 50 dB

• Inputs: 60 mV line input, 0.5 mV microphone input with level control

• Outputs: 1.23 V line output plus DIN and headphone jacks

• Construction: Solid-state electronics with 11 silicon transistors and 2 diodes

• Dimensions: Approximately 343 x 343 x 230 mm (13½ x 13½ x 9 inches)

• Weight: About 14 kg (30.8 lbs)

• Manufacture Date: 1965-1969, Japan

• Features: Mechanical controls, no built-in amplifier or speaker, notable for cross-field recording system which reduces high-frequency distortion compared to typical combined bias/record heads

• Price at Release: Around $440 in 1969

The X-150D was a respected mid-60s consumer reel deck known for its sound quality enhancement due to the patented cross-field head, compact design, and reliable motor system.