Archive / Classics, 1946 to 1969
Stereo 20
Stereo 20 (Point One Stereo 20). Power amplifier, Leak, 1958
Leak's two-channel EL84 power amplifier, shown at the April 1958 Audio Fair in London, rated at 10 watts per channel at 0.1% distortion.
A-12, isometric, same camera for both
- Drawing
- A-12
- Introduced
- 1958
- Produced
- Not published
- Made in
- United Kingdom
- Designed by
- Harold Leak
- Launch price
- 29 guineas (GBP 30 9s), 1958; the matching Point One stereo preamplifier was 20 guineas
- Size
- Not published
- Weight
- Not published
H.J. Leak and Company introduced the Stereo 20 in April 1958 at the Audio Fair in London, sold under the Point One name that Harold Leak had applied since 1945 to amplifiers with 0.1% distortion. It delivers 10 watts per channel from EL84 output valves in an ultra-linear stage, with two ECC83 valves in the driver stage and a GZ34 rectifier. The finish started as Champagne Gold, changed to Gold Bronze and became dark grey in 1964. The Stereo 50 and Stereo 60 with EL34 valves followed as higher-power versions.
Specification
| Item | As published |
|---|---|
| Output | 10 watts each channel |
| Distortion | 0.1% on each channel |
| Valves | EL84 output (ultra-linear), 2 x ECC83 driver, GZ34 rectifier |
| Frequency response | 20 to 20,000 c/s |
| Feedback | 24 dB |
| Noise | -80 dB |
| Output impedance | 4, 8 and 16 ohms |
Out of production
Find an original
The Stereo 20 (Point One Stereo 20) is out of production. Originals change hands on the marketplaces listed here; buy restored, or budget for recapping and new valves.
The house
- Founded
- 1934
- Founder
- Harold Leak
- Origin
- London, United Kingdom
- Today
- Sold to the Rank Organisation in 1969, then revived by the IAG Group in 2020 after years of dormancy.
Further sheets
Sources
- https://hifipig.com/leak-stereo-20/
- https://keith-snook.info/manufacturers-averts/LEAK-1959.pdf
- https://keith-snook.info/manufacturers-averts/LEAK%20TL12%20Plus%20.pdf
- https://en.wikipedia.org/wiki/LEAK
- https://hifi-wiki.com/index.php/Leak
- https://www.radiomuseum.org/r/leak_stereo_20.html
Notes for the record: The 29 guinea price is from hifipig; a 1959 Leak price sheet on keith-snook.info (OCR text) lists the Point One Stereo 20 at GBP 30 9s, which equals 29 guineas. That sheet also gives 24 dB feedback, -80 dB noise and ultra-linear EL84 output. The hifipig article gives frequency response as 20 to 20,000 Hz plus or minus 0.5 dB and signal to noise as 80 dB. No dimensions or weight were found for the Stereo 20, so both are null; the sibling TL/12 Plus is listed at 10 x 7 7/8 x 5 15/16 in and 14.5 lb in a Leak brochure, but that is a different amplifier. Radiomuseum dates its Stereo 20 entry 1962 and its US-market entry 1959 with a question mark. The designer credit follows hifipig, which calls the Stereo 20 the pinnacle of Harold Leak's work, and Leak's TL/12 Plus brochure, which says that amplifier was designed by Harold J. Leak; no source says so in those exact words for the Stereo 20. The brief allowed either the Stereo 20 or TL/12 Point One; the TL/12 (1948, 12 W, two KT66) is a separate model.