Akai GX 210D

The Akai GX-210D is a mid-1970s consumer to semi-professional reel-to-reel tape deck known for its solid-state reliability and quality tape handling. It was manufactured in Japan and marketed for both home and light studio use.

Technical Overview

• Track System: 4-track, 2-channel stereo auto-reverse system.

• Heads: Two GX heads — one combined record/erase head and one playback head made with Akai's advanced Permalloy alloy.

• Motors: Three motors total:
  One 4/8-pole self-lubricating hysteresis synchronous capstan motor driving the tape at accurate speeds.
  Two 6-pole eddy current outer rotor motors for supply and take-up reels ensuring smooth tape flow.

• Tape Speeds: 3¾ ips (9.5 cm/s) and 7½ ips (19 cm/s).

• Frequency Response:
  7½ ips: 30 Hz to 25 kHz (±3 dB) using low noise tape
  3¾ ips: 40 Hz to 20 kHz (±3 dB)

• Wow and Flutter:
  Less than 0.08% RMS at 7½ ips
  Less than 0.12% RMS at 3¾ ips

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

• Total Harmonic Distortion: Less than 1.5%.

• Tape Size: Supports reels up to 7-inch diameter.

• Inputs: Two microphone inputs (0.3 mV, 4.7 kΩ), two line inputs (60 mV and DIN 0.5 V), with dedicated level controls.

• Outputs: Stereo line outputs at about 1.23 V (0 VU) and headphone output (150 mV / 8 Ω).

• Additional Features:
  Auto-reverse function with fast direction change (2–3 seconds).
  Digital 4-digit tape counter for precise tape positioning.
  Tape selector for different types of tape for optimized bias and equalization.
  Durable mechanical design and oil circulatory system within the capstan motor for long life.

• Dimensions: 368 mm (W) x 371 mm (H) x 227 mm (D).

• Weight: 15.4 kg (33.9 lbs).

Summary

The Akai GX-210D is a reliable and well-featured reel-to-reel tape deck representing a balance between consumer and semi-professional quality in the 1970s. Its hysteresis synchronous capstan motor and dual reel motors provide smooth tape movement and speed stability suitable for accurate stereo playback and recording. While it lacks some professional-level recording features, its broad frequency response, low flutter, and multiple inputs and outputs have made it a well-regarded machine for home enthusiasts and semi-pro use.