Ampex AG 350

The Ampex AG-350 is a professional-quality, tube-based reel-to-reel tape recorder from the mid-1950s to 1960s, designed primarily for 1/4" tape in a half-track, monaural configuration.

• Tape Speeds: 3¾, 7½, and 15 inches per second (ips).

• Tape Format: 1/4" wide tape, half-track mono.

• Frequency Response: Up to 15 kHz at 15 ips speed.

• Wow and Flutter: Less than 0.15% RMS at 15 ips, ensuring stable playback.

• Signal-to-Noise Ratio: Around 60 dB (full track).

• Tube Complement: Multiple vacuum tubes including ECC83/12AX7, 12AU7, and others for amplification and control.

• Transport: Electrically controlled push-button operation with start, stop, fast forward, rewind, and record controls.

• Separate record and playback heads allowing for off-tape monitoring.

• Bias Frequency: Approximately 100 kHz.

• Inputs/Outputs: Balanced or unbalanced mic and line inputs; line outputs with +8 dBm into 600 ohms.

• Dimensions (with console): Approximate height 48", width 25", depth 29".

• Weight: Approximately 168 lbs (including console).

• Power Requirements: Designed for 110-120V or 220-240V AC with variants for different voltages.

The machine is robust and designed for continuous professional usage with three precision motors (two torque motors and one hysteresis motor).

• Full or half-track models were available, including mono, stereo, and three-channel versions.

• Known for quick tape speed ramp-up (full speed in 0.1 seconds) and stable operation with minimal tape movement when stopped.

• Features include a unique 30-degree sloped deck plate allowing a compact ergonomic design and remote control capability.

• The AG-350 offers NAB standard equalization and a high-quality permalloy head system.

This model was widely used in studios, radio stations, and other professional audio environments.

• Valued for its sound quality, reliability, and ease of use.

• Maintenance includes tube replacement, belt changes, cleaning, and periodic alignment to retain peak performance.

• Offers a blend of vintage warmth and professional recording capability.

In summary, the Ampex AG-350 is a classic, professional-grade reel-to-reel tape recorder designed for half-track mono recording with high fidelity, robust construction, and features suited to demanding audio production environments of its era.