II
Power amplifier, Quad, 1953
A compact 15-watt monaural KT66 power amplifier that stayed in production from 1953 to 1970, with about 90,000 units made according to Wikipedia.
A-04, isometric, same camera for both
- Drawing
- A-04
- Introduced
- 1953
- Produced
- 1953 to 1970
- Made in
- United Kingdom
- Designed by
- Peter Walker
- Launch price
- Not confirmed
- Size
- 330 x 125 x 165 mm
- Weight
- 8.3 kg
Peter Walker founded Quad in London in 1936 and moved production to Huntingdon, England, in 1941 after wartime bombing. The Quad II followed in 1953 as a mono power amplifier that also powers the companion QC II control unit and Quad FM tuners. It uses two KT66 output valves, two EF86 input valves and a GZ32 rectifier. The company still sells a recreation, the QII-Classic, which Quad says uses Peter's circuit with equivalent valves.
In the collections of National Museum of Scotland (per Radiomuseum listing) and Das Rundfunkmuseum, Cham (per Radiomuseum listing).
Specification
| Item | As published |
|---|---|
| Output | 15 W, 20 to 20,000 Hz |
| Valves | 2 x EF86, 2 x KT66, 1 x GZ32 |
| Frequency response | 20 to 20,000 Hz within 0.2 dB; 10 to 50,000 Hz within 0.5 dB |
| Configuration | Monaural, one amplifier per channel |
Reissued
Quad QII-Classic
Quad builds the II again. Pricing is through dealers.
The house
- Founded
- 1936
- Founder
- Peter Walker
- Origin
- London, United Kingdom (moved to Huntingdon in 1941)
- Today
- Quad HiFi has belonged to the IAG Group of brands since 1997 and is based in Huntingdon, England.
Further sheets
Sources
- https://www.radiomuseum.org/r/acoustical_ii.html
- https://en.wikipedia.org/wiki/Quad_Electroacoustics
- https://quad-hifi.co.uk/products/qii-classic
Notes for the record: Radiomuseum dates the amplifier 1954 with a question mark and asks for proof of 1953 sales; Wikipedia gives production from 1953 to 1970. Radiomuseum lists 466 DM as the first-year German price, a German price, so launch_price is null. Walker is credited by inference: Wikipedia names him founder and Quad's QII-Classic page refers to Peter's circuit; no opened source states plainly that he designed the Quad II. Dimensions and weight are Radiomuseum's 330 x 125 x 165 mm and 8.3 kg. The museum entries rest on Radiomuseum's museum mentions alone.