Pre/Power Amplifiers

Goodness me! Two Quad scoops in one season! OK, so it's not like waking up with Kim Basinger, but I am fully aware of the privilege. When I kicked off the Quad 989 loudspeaker review [HFN Jul '00]

DNM's long-awaited update to the PA3 power amplifier has finally arrived. Fully regulated, the PA3 S reflects the uncompromising approach of its designer Denis Morecroft. Offering just 23W per channel but costing £3750, this stereo power amp has undergone a long gestation, the reasons for which Morecroft outlines in our interview boxout.

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.

Ever get the feeling we've been here before? Well, the arrival of the latest amplifier system from Musical Fidelity brings a new twist to the whole déjà vu thing as the Nu-Vista naming and macho aesthetics are familiar from the historically hefty Nu-Vista 800 integrated amplifier [HFN Nov '14]. In practice that classic nuvistor tube-equipped integrated amplifier, also rated at 300W/8ohm, has provided the inspiration for both the industrial and technical design of the PRE and PAS we see here, the hybrid nuvistor/transistor concept now evolved into a pre/power set-up, complete with separate PSUs for each. So one box is now four...

Hands up those who have seen a Bryan amplifier before, let alone heard one. Me neither – until I unpacked the Mark III Model 500/700 pairing seen here. The first 500 arrived when higher-power transistors were beginning to be used in quality audio, yet while the technology became universal, British brand Bryan sank without trace.

Musical Fidelity is no stranger to big power amplifiers. Its top-of-the-range monoblock, the £3599 M8s-700m, claims a 700W/8ohm output and weighs in at 35.5kg, and the company sells a stereo model in the M8 series too, the £3999 2x500W/8ohm-rated M8s-500s. But perhaps what few expected from the brand, considering its range also consists of DACs, streaming amps, phono stages and CD players – everything a two-channel audiophile could want, in other words – is a seven-channel amplifier. Which is what we have here, in the shape of the M6x 250.7.

Until this year, the flagship power amplifier in PS Audio's stable was the BHK Signature 300 [HFN Jul '16]. Still on sale, it bears the initials of Bascom H King, the veteran designer (Infinity, Constellation Audio and more) who was given license by the Colorado-based company to engineer a high-output monoblock amp around his favoured tube/solid-state hybrid topology. Six years on from launch, the '300 model has been relegated to second-tier status, replaced by the PerfectWave BHK M600.