Quad 50E (1966–1983)
A solid-state mono power amplifier built for professional broadcast and studio use.
Overview
The Quad 50E is a single-channel amplifier designed for broadcast, recording, and industrial audio applications. Manufactured by Acoustical Mfg Co Ltd under the Quad brand, it was produced from 1966 to 1983 with approximately 12,000 units made. Unlike consumer stereo amplifiers of the era, the 50E was engineered as a mono block for professional environments such as studios and public address systems. It delivers 50 watts into 8Ω and supports multiple output impedances for maximum power transfer across different loads.
Specifications
| Power output | 50 watts into 8Ω (mono) |
| Frequency response | 30 Hz to 20 kHz, -1 dB unbalanced |
| Input sensitivity | 0.5Vrms unbalanced |
| Output connections | Maximum power transfer at 5.8, 12.5, 23, 50, and 200 Ω |
| Product type | Single channel amplifier designed for Broadcast |
| Production years | 1966 to 1983 |
| Production quantity | 12,000 units |
Design
The Quad 50E is a solid-state amplifier featuring an output transformer connected to the front panel via ribbon cable. It includes an octal socket on the rear for an input balun transformer, supporting balanced signal integration in professional setups.
Context
Before the introduction of the Quad 303, the 50E served as Quad’s first 50-watt solid-state single-channel amplifier. It was specifically developed for use in broadcast, recording, and other professional audio industries, reflecting Quad's engineering focus beyond the consumer hi-fi market.
Market
Due to its age, the electrolytic capacitors in the Quad 50E are likely past their operational lifespan and may require replacement. Replacement PCBs and service manuals are available from third-party suppliers, supporting restoration and long-term maintenance.
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