Rotel Michi X5 Integrated Amplifier Review
David Price gets to grips with this mammoth single-chassis powerhouse …
Michi X5 Integrated Amplifier
AUD $8,999 RRP
Having reviewed Rotel's Michi series P5 preamplifier and S5 stereo power amplifier around a year ago, it was time for me to experience the X5 integrated amplifier. I have to report a certain degree of initial scepticism, as so often, monster single-chassis designs don't cut the mustard for me. I often get the sense that in trying to please everyone – by throwing everything in but the kitchen sink – they end up pleasing no one because the sonics aren't up to scratch. Bitter experience has taught me over the years that the fancier that hi-fi at this level looks, the less impressive it can sound.
The manufacturer says that the Michi X5 pumps out a colossal 350W RMS per channel into 8 ohms, 600W into 4 and 1,000W into 2. This comes not via MOSFETs or Class D power modules but six pairs (per channel) of Sanken MN/MP1526 bipolar transistors running in Class AB. Interestingly, the company hasn't gone the Class D route to get this ceiling-lifting power. Rotel's Chief Technology Officer, Daren Orth, explained to me that:
We have been designing and manufacturing high performance, high quality electronics for over 60 years. Class AB, linear amplification is our DNA.
Experience has taught me that in my room, with my Yamaha NS-1000M loudspeakers (with a quoted sensitivity figure of 91dB), I rarely use more than around 10W of power. I regularly run valve amps of 12W to 15W, and they go pretty loud. So what's the need for the surfeit of power that the X5 boasts, you ask? Well, in my case, it's load driving – this big Rotel has tree stump-pulling torque, and of course, dynamics…
For example, crashing crescendos such as those on Los Endos by Genesis need plenty of power in reserve to capture the hard-hit snare drum and bass drum thwacking together in unison, as Steve Hackett lets rip one of his trademark guitar licks. Momentarily, the amp might be putting out 100W instead of 10W just fractions of a second before. That's where a really powerful amplifier counts for something, but it is, of course, contingent on the way it delivers this – and that's where proper auditioning beats reading from spec sheets.
Of course, this giant Rotel has great bragging rights. Measuring 485x195x452mm and weighing 43.8kg, it's big, beefy and utterly dominating of any domestic space you put it into. It has the on-paper power to fry the voice coils of many loudspeakers and flap your flared trousers. Yet it's no thuggish brute – indeed, the X5 looks rather civilised, house-trained even. It has copious amounts of user-definable analogue inputs, including moving magnet (5.7mV) and moving coil (0.57mV) phono, balanced and unbalanced, plus digital inputs, USB and aptX Bluetooth – all controlled by a slick user interface, including a MUSE 72320 precision volume controller. The latter's 0.25dB steps and optimised gain curve make the X5's power very easy to unleash.
Although the amp – which comes in any colour you like as long as it's black – looks a bit austere and imposing, it has perfect table manners. The large volume control, allied to a large OLED display, feels really nice to use, as does the same-sized source selector opposite on the left; the remote control is also excellent. All the various smaller functions – including tone controls – are easy to access. The internal DAC works up to 32-bit, 384kHz (albeit only via the USB input), and there's MQA and Roon support. Using the Michi X5 is all so easy and civilised – and, dare I say it, convenient. Purists won't like it, then!
However, they might just suspend their disbelief if they take a look inside. It's quite a sight – each mono power amp board has its own huge, custom-made toroidal power transformer and two massive smoothing capacitors. The company is very proud of these Rotel-designed and built trannies, which are said to deliver 1.525K V-A of output. Daren continued:
These are dedicated and isolated to the left and right channels respectively feeding a bank of four BHC British engineered 22,000uF slit-foil bulk storage capacitors, totalling 88,000uF for deep, controlled bass energy.
To the rear, mounted to the back panel socketry to minimise signal path lengths – are two preamplifier boards, one of which sports the highly respected AKM 4495SEQ 32-bit, 768kHz DAC chip with custom-engineered external output filters. Considerable vibration damping is used throughout the chassis, along with patented slit foil, bulk storage capacitors and other assorted fancy components such as metal film resistors and polystyrene or polypropylene capacitors in critical signal paths.
Daren says the physical separation of separate components helps to eliminate noise to the most sensitive circuits.
The X5 was designed with all of these critical elements to carefully place low voltage circuits farther from the power amplifier output transistors and independent windings on the dual transformers for the analogue and digital circuits. The amplifier was engineered as dual mono design to eliminate crosstalk and provide further isolation and lower noise and distortion.
The X5's phono stage is a discrete transistor design using thermally coupled transistor pairs to ensure a precise RIAA gain curve. Again, serious stuff!
With all this functionality and connectivity, you'd expect the rear panel to be busier than a shopping mall on Christmas Eve, but strangely it isn't. That's because the amplifier is so massive that there's plenty of real estate to fit its many inputs and outputs. Everything seems to be included, including three coaxial digital ins, three TOSLINK digital ins, a USB-B digital in, four pairs of unbalanced RCA analogue ins, one pair of balanced XLR analogue ins, RCA phono preamp outputs, two mono subwoofer outputs and an Ethernet network control port. Oh, and let's not forget the two sets of speaker terminals paralleled up – and the front panel mounted headphone jack.
The Michi X5 was more of a journey than is usual for me. I initially didn't fully warm to it, but came away, six weeks or so later, really respecting it and not wanting to move on to my next review amp. Indeed I would say that 'respect' is the operative word because, above all else, that's what it engenders. It doesn't have the obvious charm of a similarly priced valve integrated, and several other solid-state rivals I tried are initially more appealing too – but as a performer, the Rotel has fantastic strength-in-depth…
Actually, it's slightly matter-of-fact, measured delivery went from being a criticism to an asset to me at least. Properly partnered up with excellent digital and vinyl sources and highly revealing loudspeakers, the X5 is capable of great things. The point is, though, it's a bit of a grower. It doesn't have much character to speak of and instead lets the music do the talking – but it doesn't flatter recordings, instead preferring to dig deep inside them with archeological zeal. It's a 'details' amp, rather than just trying to convey the big picture – but to appreciate its forensic accuracy, as I said, you need a suitably good system to suit.
Let me give you an example. I had an Exposure 3510 integrated to hand and cued up a slice of classic rock in the shape of Rush's Red Barchetta. This amp proved heaps of fun, with a big, bombastic presentation and a creamy, rich tonality. The Rotel X5 sounded tonally thinner and didn't quite have the superficial ebullience of the Exposure. Yet the more I listened, I realised the 3510 had soft, soggy bass, compressed dynamics, a narrower soundstage and way less air and space. The X5's initially slightly analytical sound redeemed itself, as it proved a great way into understanding this track. Indeed I simply didn't want to go back to the Exposure after I'd heard what I had been missing.
That's the Rotel's skill – it tells you what's on the recording with great accuracy and precision. So if it's a relatively thin and dry classic rock track you're playing, then that's how it comes over. On the other hand, if it's Cafe Regio's by Isaac Hayes – a super-sweet early seventies Stax soul track – then magically, this amp sounds warm, sumptuous and expansive. And when this amp does get a great recording to play with, it really does sound magnificent. Suddenly you realise that it's actually a fabulous performer, in its way.
Along with its forensic detail capability and tonal neutrality, the other defining characteristic of this amplifier is its combined power, drive and dynamics. These three criteria are not one and the same thing. For example, whenever you listen to an amplifier playing music in a system, much of what you're hearing is a function of the electrical relationship between the power amplifier and the loudspeakers. The speakers impose a load on the amp, which it must manage while adding gain. It also needs to swing lots more power fast, when called on to reproduce dynamic transients.
The Michi X5 is one of the best integrated amps I have come across at doing this, appearing completely indifferent to reactive loads from troublesome speakers. It took my Yamaha NS-1000Ms – which are a handful to drive loud – and shook them around like an Alsatian with a rag doll toy. It simply wasn't in the least bit bothered about the speakers on the end of it and sounded as relaxed as if it were driving a pair of Klipschorns. In addition to this, the X5 squeezed remarkable dynamics out of my big Yammies. I don't think I've heard any other integrated amp to date with the ability to really make these speakers go loud on a transient peak in the way the Rotel can.
So this amplifier tracks the dynamics of the music it's playing in a highly faithful way. Prefab Sprout's Bonny, for example, is a lovely slice of eighties pop with a gorgeous Thomas Dolby production. Played loud, and I mean very loud, the Rotel stayed smooth and clean and measured, never grating. And when those snare drum strikes came at the beginning of each chorus, the effect was hugely satisfying. There was absolutely no sign of strain, and none of the other parts of the dense mix clouded over. So powerful was it that I found myself wondering why my speaker's midband and treble drivers hadn't catapulted themselves out of the cabinets – such was that visceral 'thwack'.
It was a really rousing rendition, with the Rotel showing great grace under pressure. This is where this amp's control shows itself to be a wonderful thing; it keeps everything together, tight and taut and correctly syncopated. This same characteristic is evident in its soundstaging, too. The Michi X5 is a very high achiever in this respect; it projects out a very large, deep and wide recorded acoustic with excellent image location.
Everything is precisely placed, strikingly so on a recording like Herbie Hancock's The Prisoner, which is the sonic equivalent of an out-of-body experience. This classic late sixties Blue Note jazz track used a simple crossed pair of microphones in the studio to give an almost holographic sound. Few integrated amplifiers recreate this recorded acoustic in the way that the Michi X5 does. It served up a wonderfully wide sound, with the flute far left and the drum kit far right, while Hancock's ivory tinkling sat central but way back in the room. This amplifier gave a glass-clear rendition of the recording, with each individual instrument practically nailed to its place in space.
Rhythmically, the Rotel swings along very well. It times much faster than you might expect a massive muscle amp to do; there's no sense that it drags its heals. Bass isn't just super strong; it's very quick too – making for a very deft reading of the aforementioned Herbie Hancock piece. It's just as much fun on modern techno, too, with K Klass's Rhythm is a Mystery powering along with seemingly unstoppable momentum, the Michi X5 dealing out vast swathes of sub-bass with total ease. It's not quite as jaunty sounding as a talented tube amp like Prima Luna's EVO400, or indeed Copland's fine CSA150 solid-state integrated. Still, it has other redeeming features that they conspicuously lack.
Rotel's Daren Orth says the new Michi platform took three years to design and develop, with one year given to the integrated version after the pre/power amps came out. Frankly, it shows. This is a super-capable, breathtakingly thorough design that works so well in so many ways. Although its styling may be modest, take a look inside if you need reminding about what a great engineering feat it is.
Sonically, I came to really rate it. For me personally, it wasn't love at first listen, but the more music I played, the more it revealed its superb ability – just like some of my favourite albums, it proved a real grower. With so much insight, detail and power, it makes the majority of its price rivals seem mushy, soft and gloopy. If you're in the market for a serious, no-compromise 'super integrated', this is undoubtedly one of the finest that money can buy.
David started his career in 1993 writing for Hi-Fi World and went on to edit the magazine for nearly a decade. He was then made Editor of Hi-Fi Choice and continued to freelance for it and Hi-Fi News until becoming StereoNET’s Editor-in-Chief.
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