Quad 405 Stereo Power Amplifier

Why Buy New is pleased to offer for sale, this brilliant Quad 405 Stereo Power Amplifier.

It has been professionally repackaged to ensure safe delivery and comes with a power cable and user manual.

This has been tested and is in full working order. It is sold with a 3 month warranty.

The cosmetic condition is good. There are some minor marks. Please see the condition in the images.

FREE national courier delivery.

Why Buy... from us?
Because all of our items go through a full inspection, get serviced (if required), PAT tested for electrical safety, deep cleaned and all come with a warranty. We are 100% committed to customer care and are always on hand pre or post-delivery for technical help and advice.

Overview

The Quad 405 is an iconic two-channel power amplifier introduced in 1975 by Quad’s founder, Peter Walker. It employs the unique "current-dumping" design, combining a low-power Class-A error amplifier with a high-power Class-B output stage. The design earned the Queen’s Award for Technological Achievement in 1978. A refined version, the 405-2, was released in 1982. 

Key Specifications

• Power Output: 100 W per channel into 8 Ω; 250 W into 4 Ω
  
• Frequency Response:
  –1 dB at 20 Hz
  –0.5 dB at 20 kHz
  –3 dB at 50 kHz
  
• Total Harmonic Distortion: < 0.01% (100 Hz, 1 kHz, 10 kHz)
  
• Input Sensitivity: 0.5 V for full output
  
• Signal-to-Noise Ratio: Approximately 95–96 dB (A-weighted)
  
• Damping Factor: About 80
  
• Channel Separation: ~85 dB at 1 kHz
  
• Load Impedance Range: 4–16 Ω
  
• Dimensions (W×H×D): 340 × 115 × 195 mm
  
• Weight: ~9 kg