We all know how great the Leak Stereo 20 is. Introduced in 1958, it was a perfectly packaged ‘do-it-all’ stereo valve power amplifier with enough power to drive most loudspeakers of its day. Using the same basic circuit as Harold Leak’s ‘Point One’, it was an evolution of the classic mono TL12 Point One. The latter evolved into the EL84-toting TL12+, offering a claimed 12 watts. Two twin channel amplifiers followed; the aforementioned EL84-powered Stereo 20 and the EL34-aspirated Stereo 50. Then came the Stereo 60, Leak’s punchiest stereo tube amp ever – so why is there so little love for it?
The Stereo 20 is decently powerful and very reliable, which is why it’s gone on to be such a friend of the classic tube amp fraternity, but the Stereo 60 is rather more troublesome and commonly regarded as inferior sounding. The upside is that it’s pretty rare and something of a curio – and with a little TLC can be made to make a far nicer noise. Although similar in its circuit design to the Stereo 20, it sports an input attenuator switch which can be beneficially bypassed. It has type 8615 output transformers with 25% screen taps – as opposed to 50% screen taps on type 3925 transformers on its Stereo 50 predecessor. The power supply is choke-regulated, and the tube complement comprises a single 12AX7 cathode gain stage, with another one making a long tailed pair for gain and phase splitting. The four EL 34 work in push/pull to produce 35W per side maximum, or 25W at a claimed 0.1% distortion. Leak specified the KT66 as being suitable for fitment as an alternative, and there was an option of using K5881s.
Any Stereo 60 is now the best part of sixty years old, so many will have been modified. Ideally this should have be done lightly, with the capacitors renewed with high quality paper-in-oil types. When this classic amplifier has been correctly fettled, it’s capable of a very nice sound – although not quite as peppy as the Stereo 20, it’s still smooth and open and three dimensional, with a typically classic valve ‘louche’ quality that makes listening a pleasure. It has fine reproduction of instrumental timbre and a lovely, sweet treble too, although the bass isn’t the tightest around. Still, there’s a decent amount of power at hand – especially for an amp of this era – and the overall effect is most pleasing.
They’re pretty rare, so expect to this to be reflected in the price. Typically, you can spend between £500 for a fixer-upper to £1,500 for an excellent, original example. Factor in spending £250 or so for a full service and/or refurbishment from a Leak specialist such as Classique Sounds, and you’ll have a lovely classic valve powerhouse – and something a little bit different, too.