Pre/Power Amplifiers

The really unusual aspect of the design is found on the input section, where there's a choice of not just single-ended RCAs or balanced XLRs, selected using a small toggle switch on the rear panel, but also a choice of XLRs – one set marked 'Bal' and the other 'Direct'. Selecting the 'Direct' position, which is done by setting the input selector, bypasses the amp's first gain stage (voltage preamp). This stage uses low-noise FETs and is fully differential/balanced – removing it takes an amp stage out of the signal chain, creating what the company calls 'Constellation Link'. Naturally, the 'Direct' input has a lower overall gain than the standard balanced one, but that is compensated for by the higher overall gain of Constellation's preamps.

That, and the presence of another small toggle switch, used to mute the power amp, means some study of the manual is required if one isn't familiar with this Constellation input arrangement. It would be too easy to hook the amp up and not hear a whisper from the loudspeakers. Completing the connectivity here are 12V trigger and RS232 control sockets, and a USB-B port – yes, even power amps are prone to firmware updates these days.

King Of Clout
The Centaur II 500 Stereo received rather more of a run in PM's listening room than is usual even during the exhaustive HFN review process, being used over several months as one of the test amplifiers for speaker reviews including the recent GoldenEar Triton One R [HFN Nov '19], Paradigm Persona 9H and the Focal Kanta No3 [HFN Sep '19] as well as driving our reference B&W 800 D3s [HFN Oct '16]. In every case it proved itself to be an unburstable ally when driven from the dCS Vivaldi One digital media player [HFN Feb '18] used as both DAC and preamp, and made it only too clear what the various speakers under consideration could do when driven properly.

Above all, the Centaur II 500 Stereo delivers all the power, clarity and dynamics anyone could want. Notwithstanding PM's slight reservations on the actual output on offer, the clout experienced in the HFN listening room was palpable. Without any sense of brooding menace, the II 500 Stereo always had power in reserve, not just for the occasional 'let's see what they can do' moment of speaker madness, but also for the real-world dynamics.

After all, loudness isn't everything, and all music exists as a collection of sonic light and shade. Even the most powerful amplifier will sound artificial if it can't respond immediately to the demands of what's being played, and that's where the Centaur II 500 Stereo truly scores, by combining its sheer might with the speed, delicacy and finesse required to illuminate the music, not steamroller it.

Rich Rewards
Playing a dramatic piece such as Britten's The Young Person's Guide To The Orchestra [from Reference Recordings RR-120; DSD64] – a recording that, by its very nature, tells one so much about how a system handles the timbres and dynamics of real instruments – the II 500 Stereo drove our suitably accomplished speakers not only to take the listener into the heart of the band, but also provide emotional surprises. The thunder of the percussion in its section of the work, and the crisp rattle of the snares, is superb, and the way the final fugue grows to its stately, massive conclusion is a spine-tingler.

But the amplifier is just as magical with the solo piano of Paul Lewis playing Mussorgsky's Pictures At An Exhibition [from Harmonia Mundi HMC 902096; 96kHz/24-bit], not only with the punchy rhythms of the faster-paced 'pictures', but also with the lovely limpid sense of the slower ones, with every note from Lewis's instrument hanging in the acoustic of Berlin's Teldex Studio. It's a delicious sound, both lush and rich but at the same time tightly defined, just as it should be.

That this amplifier can rock is beyond question: its combination of speed, grip and sheer grunt ensures it drives speakers hard and tight with everything from the histrionics of Queen's 'Keep Yourself Alive', from the band's eponymous first album [Universal/Island UIGY-9510; DSD64] through to the refined soft rock of 'Listen To What The Man Said' from Paul McCartney's Pure McCartney retrospective [Concord Music Group/MPL HRM-38690-02; 44.1kHz/24-bit]. The agility of this amp, belying its apparent status as a big ol' bruiser, is consistently in evidence, to exceptionally satisfying effect.

Play jazz, it swings; play rock, it bares its teeth; play chamber music, it glides – whatever you want, the Centaur II 500 Stereo delivers. But then one might suggest that at the price, it surely ought to...

Hi-Fi News Verdict
So does the Centaur name make sense? Well, this amplifier plays music on a human scale, while delivering no shortage of giddy-up when required. Although by no means the costliest of Constellation amplification, it still exists in a very rarefied stratum of hi-fi, but justifies its price-tag with impressive build, and a sound combining solidity and dynamics with delicacy and refinement. It deserves an extended audition.