Mastersound Evolution 845 (Hi-Fi+ 79)

Integrated amplifiers
Mastersound Evolution 845
Mastersound Evolution 845 (Hi-Fi+ 79)

Italian audio has two main thrusts today; gorgeous design and a passion for valves. So it’s perhaps no surprise where Mastersound comes from. The new Evolution 845 integrated amp from the brand comes from Vicenza in north-east Italy.

It’s definitely got the looks. The oversized design with wooden side cheeks, the black transformer cans, the metal top and the exposed valves are extremely elegant and not too dissimilar from Unison Research models (built some 50 miles away), but the elegant stacked heat sink/valve cage of the Mastersound gives it an class of its own.

And it’s certainly got the valves, a quartet of 845 power triodes. Until a couple of decades ago, large valves like the 845 (and 211) were all but forgotten. Their original use (radio transmitter power valves) was long since transistorised and aside from a few interested parties, they would have disappeared into complete obscurity. Fortunately, one of the interested parties was the late Hiroyasu Kondo of Audio Note who in 1988 released the Ongaku, which featured a pair of giant 211 power valves and delivered some 27 of the finest watts (a lot of) money could buy. This opened the floodgates and products featuring large power triodes culled from 1930's radio, cinema and telephony began to appear. Mastersound – beginning in 1994 – is one of the leaders in the field.

There is a school of thought that a valve amplifier is only as good as its transformers. This is simplistic thinking, like saying a camera is only as good as its sensor, but there is more than a ring of truth to the claim. Certainly because the output transformer couples the amplifier circuit to the loudspeaker in conventional single-ended and push-pull valve amp designs, there’s many a good circuit wrecked by inappropriate transformer use. Mastersound doesn’t have that problem, because it designs its own transformers to its own specific specifics. Which leads us to the simplistic test for that simplistic thinking – the heavier the transformers the better. Once again, Mastersound wins out, with some of the beefiest potted transformers around. So heavy in fact, the two output transformers have two smaller power transformers in orbit around the rest of the top plate. Joking aside, this bespeaks of a truly dual mono design, with only the plug, motorised volume and source selector shared between the channels. It also makes that 53kg load very rear-heavy, which can prove interesting if one of the two-man lifting team isn’t aware of the unevenness.

OK, there’s a little confession here; most weighty transformers are heavy because of the amount of metal, but these ones go a little further. Mastersound’s designer precisely specifies the number of windings, demands Litz wire windings, insists on a no-solder policy inside the transformer and then pots the thing inside a can filled with a resin and gravel (no, really… gravel) mix. This not only damps the transformer perfectly, and adds a lot of mass, it acts as a security measure; unscrupulous amp designers trying to find Mastersound’s secrets will destroy the transformer in the process of removing it from its casing; short of calling in Lara Croft and a bomb disposal team, Mastersound’s secrets are safe.

The amplifier itself dispenses with the old-school point-to-point wiring that seems to be the current valve vogue, instead using very serviceable large circuit boards and those 845 tubes sports a pair of ECC82 double-triodes as preamp drivers and a pair of 6SN7GT as drivers in the power amp stage. It has three line inputs and one direct input that by-passes the volume control. All these are single-ended, and the amp features decent gold-plated phonos at the rear. These are joined by four and eight ohm taps for speaker output. There are also biasing controls at the rear of the amp, but Mastersound recommends expert help here. Finally, there’s an under the chassis power switch, a wooden remote that operates volume up and down and nothing else and the whole caboodle sits on four Michell-sized black cones. You’ll need a large table too, because it’s a biggie. Overall fit and finish is very good; just the right balance between bling and understatement for most people.

A zero-feedback, parallel single-ended design featuring a pair of 845s per side is capable of pumping out 55 watts per channel, but the Evolution 845 nevertheless demands an efficient loudspeaker design. A lot of this comes down to the dynamic headroom the amplifier delivers, which means instead of using up the power simply driving a moderately efficient loudspeaker, the Evolution 845 is in its happy place playing at a fair lick while cruising and then delivering huge dynamic swings from its power reserves. A pair of Tannoy Definition DC10T floorstanders fit the bill perfectly (in fact, Mastersound and Tannoy should consider this review something of a matchmaker – the marriage is a very happy one, far better than, say, an Armani kilt or tatties and tagliatelle). I’m sure the usual valve suspects (horns, efficient paper coned speakers, products from Audio Note, Living Voice, Zu, etc, etc) will do just as well.

When appropriately partnered, the Mastersound Evolution 845 is a delight to listen to, especially with classical and vocals. It breathes with live, unamplified instruments and feels like it gives the instruments the chance to sing out as they were made to.

Like many good amps, this starts from the midrange out. The mids are intensely satisfying, in they way scrambled eggs on hot buttered toast on a cold winter’s morning is intensely satisfying – naughty, but nice. Midrange sounds here are lithe and entice you to listen longer. No, they won’t turn PJ Harvey into Ella Fitzgerald, but the Mastersound’s midrange combines vocal clarity and articulation with a huge soundstage and a seductive richness that draws you in.

Moving away from the midband is not a wrench, because the treble is clean, extended and very attractive. The harmonic richness of the midrange appears to extend into the high frequencies, giving the overall sound a sense of coherence and natural balance that is often lacking in this ‘boom/tizz’ modern world. Once again, there seems to be a pattern to the way you discover the sound of the Evolution 845; that harmonic structure hits you like the top notes of a perfume, this is followed by the middle or heart notes of tying all the music together cohesively and finally a base note of large sense of soundstage scale. And yet again, I found myself drawn more toward vocals and acoustic instruments and away from wailing guitars and headbanging.

The bass is almost as strong as the mid and top. Once again, the sense of harmonic structure, huge soundstage and overall coherence hold a lot of sway and will win over many people. And once again, the way the bottom end charms and seduces you with live, unamplified music is hugely persuasive. But there is a slight euphony here, the bottom end is almost too lush – it’s the sort of amplifier that makes the piano on ‘Willow Weep for Me’ by Sarah Vaughan at Mister Kelly’s sound a fraction slow next to her voice and yet paradoxically speeds up the somewhat ponderous rhythm section on ‘The Quality of Mercy’ by Michelle Shocked on the Dead Man Walking OST. This is ultimately an image solidity issue, and is the place where this valve amp sounds most ‘valvey’; musicians don’t sound as rooted in space as they can when played with the sort of control of a top-notch solid-state design. But you need a good reference point to notice this kind of euphony. Having lived with a Devialet D-Premier for a while now, I don’t think I would count myself among those craving that euphony anymore, but even being used to the bloodiest of bleeding edge sounds now, I have to admit this one sings a siren’s song.

That’s the magic of the Mastersound Evolution 845. Turn it on, wait half an hour and the sound is so seductive it’s hard to resist its charms, even if what you normally listen to (both in terms of audio technology and the sort of music at which it excels) is very different. If you think valve amps are all about squidgy soft and warm sounding, the Mastersound is the natural way to show just how wrong preconceptions can be. Anyone with a penchant for acoustic music – especially if you own a pair of big Tannoys – might find their system undergoing some radical Evolution soon.


Stereo dual mono integrated amplifier in Class “A”
Parallel Single ended
Power tubes: 4 x 845
Pre-driver tubes: 2 x ECC82
Driver tubes: 2 x 6SN7 GT
Power: 2 x 55Watts
Inputs: 3 line + 1 direct RCA phono
Input impedance: 100 K ohm
Load impedance: 4 - 8 Ohm
Negative feedback: 0 dB
Bandwidth: 8Hz-40kHz – 0 dB
Dimensions (WxDxH): 54 x 47 x 27 cm.
Weight: 53 Kg
Price: £9,495

Manufactured by Mastersound

Distributed by Jordan Acoustics
Tel: (UK only) 0800 121 4771

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