Pre/Power Amplifiers

At first glance, one might be forgiven for wondering what's going on here – after all, California-based Constellation Audio already has a Centaur II stereo power amplifier on its books, selling for a not inconsiderable £48,000. So the $64,000 question must surely be 'what is this second version, dubbed the Centaur II 500 Stereo, bringing to the party?'.

Or rather it's the £64,998 question, for that's what this latest stereo power amp in the company's Performance range will set you back. If you want even more of the same, you could opt for the Centaur II Mono amps, at a cool £47,998 apiece – clearly £998 is the new £0.99 when it comes to pricing in the higher-end – or even move on to Constellation's Reference line. These power amps, the Hercules II Mono and Stereo, are listed by UK distributor Absolute Sounds with a discreet 'POA'. If you need to ask…

Head Spinning
OK, so there's an easy answer to what the extra £17k over the 'standard' Centaur II gets you, and the clue is in the name, for the lesser amplifier gives you 250W per channel, while the '500' version... aww, you guessed it. However, that can't be the whole story, as the company's Inspiration Series Mono 1.0 amps [HFN Oct '19] will also deliver 500W for a tad under £26,000 a pair, and even the Revelation Series Taurus Mono amps, another 500W, are well short of the Centaur II 500 Stereo at just under £46,000 for the brace.

Head spinning enough with all those numbers? Now you know how your humble reviewer feels when confronted with the big, bluff edifice that is the Centaur II 500 Stereo power amp – all 68kg of it – and realises that we're not just in 'the price of a decent car' territory. Flicking on the kitchen TV while having a mid-morning coffee break, we saw houses on fixer-upper property show Homes Under The Hammer selling for less than this amplifier – and that's after they've been fixer-upped!

So, taking a deep gulp of the very thin air up here in hi-fi's mesosphere, what is the Centaur II 500 Stereo all about, beyond that headline output figure? Well, in essence this is the existing 250W Centaur II Stereo, into which has been transplanted a power supply derived from the flagship Hercules II amplifier. Or, as Constellation puts it, when it upgraded its original Centaur stereo amp to MkII status, its engineers 'ended up with an amplifier they knew could deliver far more than its rated power, if only the power transformer could provide enough voltage. As an experiment, they installed one of the transformers from our Reference Series Hercules II into a Centaur II Stereo chassis. The experiment worked even better than they imagined, producing the Centaur II 500: a stereo amplifier with the same power rating as a pair of Centaur II monoblocks'.

And, as we've seen, the 500 Stereo saves you over £34k compared to a pair of those mono amps – beginning to look like a bit of a snip now, isn't it? Of course, just slamming in a bigger transformer – actually one of the pair of 3kW-capable devices the Hercules II Stereo uses – isn't the whole story. In addition, Constellation has increased the maximum voltage of each of the power supply capacitors by 30% to handle the new higher rail voltages. However, the output stages and their heatsinking were left untouched, as they were already up to the demands of the increased output.

Direct Connect
Editor PM goes into the design of the output section in his Modular Magic boxout but outside the chassis at least, the Centaur II 500 Stereo is pretty much a conventional solid-state power amp, albeit with one or two twists of industrial engineering. The main power switch is on the rear of the amplifier, with on/standby controlled by the bar on the front. With the power on, the central LED glows red, with a long push on the left side of the bar initiating a soft start/self-diagnosis procedure during which the lamps flashes green, the LED turning blue and the amp unmuting once powered up and stable.