Akai GX-636

• Track System: 4-track, 2-channel stereo/monaural with auto reverse and both-way recording

• Heads: Six heads total — 2 record heads (GX type), 2 playback heads (GX type), and 2 erase heads, all made from high-quality glass crystal ferrite for long life and excellent sound clarity

• Motors: 3 motors — 2 eddy current outer rotor motors for reel drive and 1 direct drive AC servo capstan motor (Center Pole Generated technology)

• Maximum Reel Size: Supports up to 10.5-inch reels

• Tape Speeds: 2 speeds: 3¾, 7½ inches per second

• Frequency Response: 30 Hz to 27 kHz (±3 dB at 7½ ips)

• Wow and Flutter: Less than 0.03% at 7½ ips

• Signal-to-Noise Ratio: Better than 65 dB

• Total Harmonic Distortion: 0.4%

• Crosstalk: 40 dB

• Inputs: 70 mV (line), 2 mV (DIN), 0.25 mV (mic)

• Outputs: 0.775 V (line), 0.3 V (DIN), headphone output

• Dimensions: 440 x 483 x 256 mm (17.3 x 19 x 10.1 inches)

• Weight: Around 21 kg (46 lbs)

• Additional Features: Feather touch logic-controlled button operation; digital real-time counter; tape tension control; mechanical analog VU meters; quoted reliable and precise tape transport; no servo tape tension, meaning tape tension varies with diameter

• Manufactured: Circa 1981–1982 with a production run ending by 1982, succeeded by newer models such as the GX-646

• Reliability and Sound Quality Ratings: Sound quality approximately 7/10, reliability 8/10 by vintage standards

• Known Issues: Some users report slow rewind/fast forward near tape ends; tape tension arm plastic insert can fail requiring replacement; transistors like 2SC458 may need replacement over time

• Serviceability: Uses GX-635D service manuals supplemented by additional GX-636 specific documents; PCB layouts differ slightly from earlier models

This model is a solid mid-high fidelity semi-professional deck with advanced features for its time and durable highly regarded GX heads engineered for longevity and superior playback/recording quality.