TEAC A-4010 GSL

The TEAC A-4010GSL is a mid-high fidelity, 4-track, 2-channel stereo reel-to-reel tape deck with auto-reverse playback, produced in Japan around 1973–1976. It is an advanced version of the popular A-4010 model, incorporating several technical improvements and user-friendly features.

Track and Head System

• 4-track, 2-channel stereo system with 4 heads: erase, record, playback, and reverse playback heads.

• Heads are made of HD ferrite with permalloy cores, featuring a ferrite shield and hard glass molding to reduce track crosstalk and enhance sensitivity and saturation levels.

Tape Transport and Motors

• Three motors:
  One dual-speed hysteresis synchronous capstan motor for precise tape speed control.
  Two eddy current outer rotor reel motors for stable tape tension.

• Tape speeds: 3¾ and 7½ inches per second (9.5 cm/s and 19 cm/s).

• Supports reels up to 7 inches (18 cm) diameter.

• Wow and flutter: 0.08% at 7½ ips, 0.10% at 3¾ ips, ensuring stable playback speed.

• Auto-reverse mechanism allows seamless playback in both directions.

Frequency Response and Sound Quality

• Frequency response:
  At 7½ ips: 40 Hz to 18 kHz ±3 dB
  At 3¾ ips: 40 Hz to 12 kHz ±3 dB

• Signal-to-noise ratio: approximately 55 dB, improved by 5 dB over the earlier A-4010 model.

• Distortion factor: about 1% at normal recording level.

• Crosstalk: 60 dB at 1 kHz, with stereo separation around 50 dB at 1 kHz.

• The deck features a bias current changeover switch and an equalizer/level switch to optimize recording for low-noise or standard tapes, allowing higher recording levels (+6 VU) when using low-noise tape.

Amplifier and Controls

• Equipped with a dedicated 4-unit amplifier system, with separate circuits for recording and playback.

• The equalizer stage is a 3-stage direct connection type.

• Double scale VU meters with an expanded linear scale for precise level monitoring, showing normal and +3 VU offset scales depending on tape type settings.

• Pause mechanism can be locked in record, playback, or stop mode to avoid clicking noise during recording start.

• Independent volume controls for microphone and line inputs allow mixing without external equipment.

• Headphone output included.

Additional Features

• New reel clamp mechanism for secure reel attachment and easy removal.

• Height adjustment on reel stand to prevent tape damage from reel edge contact.

• Delay circuit in the pinch roller mechanism to protect tape during reverse playback.

• Reverse playback can be automatically triggered by sensing foil on the tape.

• Timer recording/playback capability with optional timer control adapter.

• Remote control available (RC-403 model).

Physical Specifications

• Dimensions: approximately 450 mm (W) x 445 mm (H) x 251 mm (D) (about 17.7 x 17.5 x 9.9 inches).

• Weight: around 20.5 kg (45.2 lbs).

• Power consumption: 97 W at 100 VAC, 50/60 Hz.