To upgrade a Quad 405 Amplifier

[Labarum]

Although I have a Quad 77 Stack for the last couple of years I have been using a refurbished Quad 405-2, which does seem to outperform the Quad 77 Integrated Amp. The 405 is a current-dumper (the 77 is not), the 405 has more reserves of power, and driving a power amp directly from a DAC shortens the signal path which surely must be an advantage.

All this is by-the-by.

A Quad 405-2 may be bought on eBay (UK) for less that £200 if you are patient. It may be sent off for refurbishment - new capacitors - new op amp and maybe converting to a dual power supply by reconfiguring the twin secondaries of the mains transformer.

The result is an extremely competent amplifier at a very attractive price that will give another ten years good service.

There are a number of places where you can have the work done

http://www.diyhi-fi.co.uk/quad405.shtml

http://www.net-audio.co.uk/quad405caps.html

or look for 405man on eBay who refurbished mine.

405man from time to time sells ready refurbished 405s on eBay. You might get one under £300.

Quad Pre-amps may also be purchased on eBay and refurbished.

About that I know less, as I only need a Power Amp.

[Sebastien]

Nothing new under the sun: Quad is famous. A long story of audio improvement and quality products.

As I never heard any Quad product, can you tell me what are the strenght of that company?

Sebastien

[Labarum]

Quad and Harbeth have often been paired. Both companies follow the same no-nonsense philosophy. Both supplied the BBC. Quad got into difficulties a few years ago and were bought out. There is no evidence the quality of the product has suffered.

The Quad 405 and 405-2 used a principle called current dumping as a means of increasing quality and reducing the crossover distortion of a Class B Amplifiers. I am told that components have much improved in recent years and techniques like current dumping are less necessary. The Quad 99 amps do not use it but the current big amp, the 909 does.

405

http://www.retrohifi.co.uk/q405r2.jpg

909

http://www.superfi.co.uk/images/main/quad-909-power-amp-1200x542.jpg

The Quad Preamps have the famous "Tilt" controls rather than conventional Bass and Treble controls.

The Electrostatic loudspeakers are world beaters.

The build quality of the electronics is excellent - it's almost as tough as military kit.

The strengths of the company? They build long lasting, no-nonsense equipment for listening to music with out a fuss. You buy it, install it, and forget it. It doesn't get in the way of the music, but delivers year after year after year - like Harbeth.

Technical specifications of the 405 are reproduced here

http://www.retrohifi.co.uk/quad%20_405-2.html