Pre/Power Amplifiers

Launched in 1980, these slimline separates proved just the tonic for those seeking sophisticated sonics wrapped in eye-catching casework. How do they sound today?

Who buys top quality hi-fi equipment? First there is the audiophile, who is willing to devote considerable resources in the pursuit of components that deliver what he or she regards as the best sound quality for a given budget. There was once also a largely non-technical group who had equally high musical expectations. Wealthy and design conscious, they wanted complete systems that not only sounded good but looked good too, and included all the latest technological refinements.

Martin Colloms hears the FET nine/e and SA/3.9e from Threshold – a company that can lay claim to being one of the founders of the high-end...

Threshold has been making high-quality amps for many years, its preamps showing early use of FET circuitry and the power amps distinguished by an output stage design which Threshold calls 'Stasis', a kind of active Class A operation. Company founder and chief designer, Nelson Pass, remains fully involved and his signature appears on the circuit diagrams included in the excellently documented operating manuals supplied with the units.

Back after a hiatus of nearly a decade, Trilogy’s founder Nic Poulson has returned to amp manufacture, having spent the interim producing mains filters and regenerators. Both the promise and the standards of Trilogy ‘Mk I’ have been maintained in the rebirth, but with new twists, including microprocessor control. Poulson has revived Trilogy with three models, continuing the 900-nomenclature of the 1990s units. The 909 preamplifier will most amuse the tweaker because it’s all-valve, using three ECC88/6922s and a 6U4P rectifier, but it boasts features usually found in cutting-edge solid-state products, or valve exotica from the likes of VTL, McIntosh and other American makers.

John Atkinson lives with Krell pre- and power amplification

Streetwise. Now there's a word. I suppose you could say that in a hi-fi context it means being aware of the unwritten myths, such as 'image depth is due to microphony in valve amplifiers' or 'Class A amplifiers sound better than ones operating in Class B' or 'the only truly great preamplifiers use valves'.

Steeped in valve lore, this iconic tube brand extends the 'voicing' of its products right down to the choice of passive components and hand-wiring. We test a stack of VAC!

With the Valve Amplification Company, aka VAC, now 30 years old, it qualifies as a stalwart of the 'third wave'. The first was, of course, the original golden age generation of Marantz, Quad, McIntosh and others of the 1940s and 1950s, while the second wave hit in the early 1970s with Audio Research, EAR and other tube revivalists. VAC arrived at the point when tubes were demonstrably here to stay, Kevin Hayes founding the company with his father in 1990. He was, and remains, resolutely focused on the high-end, as this pairing's £69,000 cost attests.

Ken Kessler takes delivery of the Audio Research SP-11 preamplifier

The time is early June, and let us imagine that this issue has been on the stands for two weeks. Editorial secretary Jennifer Scotland walks to where I am sitting and dumps a pile of letters on my desk. The angry correspondence has arrived.

With VFETs costing top dollar and facing stiff competition from other semiconductors, the late '70s saw Yamaha unveil a new pre/power amp duo. How does it sound today?

It's always intriguing to see how a company reacts to the realisation that a technology it has championed is reaching its sell-by date. This was the situation faced by Yamaha in the late 1970s. Since the middle of that decade, its top-end products had made use of Jun-ichi Nishizawa's Static Induction Transistor – more commonly known as the VFET – to great effect. This led to the development of designs such as the B-1 and B-2 power amplifiers, and C-1 preamplifier, all of which are still held in high regard.