Amplifiers/Processors

Eight channels? When I first saw the spec sheet for Primare's new power amplifier I did wonder if I'd read it wrong, because in the home cinema arena we're used to odd numbers. Yet the A35.8, thanks to flexible internal engineering, considers eight to be just the right amount, whether you're interested in movies or music.

Yes, music. Sweden's Primare has been so focused on hi-fi hardware recently (its current Prisma range of two-channel devices extends to DACs, network players, CD decks and integrated amps) that I wouldn't have expected it to suddenly unleash a power amp solely aimed at home theatre installs.

So the A35.8, a new stablemate for the pre-existing A35.2 stereo power amp, intends its eight channels to be put to use even by someone using just a pair of speakers. How so? The eight channels are arranged in four bridgeable pairs, giving you a four-channel amp if you desire. Those four channels can then be used to bi-amp a pair of speakers if they have the appropriate split crossover and terminals. Eight becomes four into two.

You'd only do this if your speakers were sufficiently high-end to justify the A35.8's £4,500 ticket, of course. Not to mention power-hungry, because you'd end up with a claimed 750W going to each speaker.

Channel Hopping
In an AV rig, the Primare's eight channels can, naturally, be used independently – each promises a hefty 150W. This is where those odd numbers come in. A 7.1 system would have a channel left over, to which Primare's answer is to bridge it and give the centre enclosure some extra clout. Or, in a 5.1 setup, bridge the L/C/R speakers and use the remaining two amplifier channels for the surrounds. And if you have 15 channels of Atmos to handle, well you could just buy two of these amps...

Making all this potent power available in a well-proportioned (430cm-wide, 14.5cm-high) pressed steel chassis that will fit easily on an AV rack is Class D amplification from Hypex. This has the benefit of being compact, with no requirement for a toroidal transformer the size of a bowling ball. It also runs relatively coolly, meaning that while the A35.8 does have heatsinks, these are mounted internally.

Indeed, take a peek inside Primare's new power pusher and it all looks rather neatly laid out. An APFC (active power factor correction) switch-mode power supply unit, with custom wound transformers, lurks behind the thick aluminium face-plate. Further back are the eight Hypex modules. Signal paths have been kept as short and pure as possible, even to the extent that the speaker binding posts are directly connected to the amps without the use of solder.

These binding posts are nicely spaced along the bottom of the A35.8's rear panel, and labelled Channel 1, Channel 2, etc. Above each set of binding posts are the inputs for your pre-amp (or the pre-outs from an AVR), which are available on both balanced XLR and unbalanced RCA. For each 'pair' (Channels 1 and 2, Channels 3 and 4, etc) there's a switch to instigate bridged mode, and the corresponding speaker terminals to then be used are clearly labelled.

Further connections are 12V trigger in/out, plus RS-232, for system integration. Even if these aren't used, the A35.8 has the wherewithal to wake from standby when an input signal is detected, and to enter standby after 20 minutes of no signal. Both these modes (Auto Sense and Auto Standby) can be defeated if desired.

As for the A35.8's overall styling, it's on the right side of functional. Some power amps adopt a black box persona, which is fine considering they're often likely to be sat out of sight, but Primare instead offers a very smart brushed-metal fascia in either silver or black. The company logo, central to the front panel, also serves as the power button, it's tiny white light glowing when it's ready to roll. During bootup, eight red LEDs inside the chassis illuminate momentarily as the amp's clipping detection system activates. Apparently these will also come on if you do overdrive any of the A35.8's channels, but this isn't something I experienced.

Ready For Anything
I auditioned this amp with both a two-channel Primare PRE35 pre-amp (with balanced XLR output), and via the multichannel RCA pre-outs on my Arcam AVR850 AV receiver. In both setups, its high-output delivery was easily apparent, as was the performance boost you can get from really giving loudspeakers a kick up the backside. Nor is this just a case of having extra grunt to help drive tough loudspeaker loads; the A35.8 has its own, welcome, sonic attributes.