Aus Hello-Fi magazine overview
This overview and take a look at initially appeared in Australian Hello-Fi journal, one among What Hello-Fi?’s sister titles from Down Underneath. Click here for more information about Australian Hi-Fi, together with hyperlinks to purchase particular person digital editions and particulars on tips on how to subscribe.
Rotel Michi S5 examined at £3299 (AU$5999). Rotel Michi P5 examined at £5399 (AU$10,399).
Can a well-known model be a sufferer of its personal success? Ask any skilled advertising person who query and their reply can be a powerful “Sure!” Take, for instance, one of many world’s most well-known motorcar producers, Toyota.
Toyota shouldn’t be solely one of the well-known automobile firms on this planet, it additionally sells extra passenger autos than every other automobile producer. However when it first tried to enter the posh car market to compete in opposition to the likes of Rolls Royce, Mercedes Benz and Daimler, with its fabulous – and well-known – Century mannequin, it couldn’t acquire any traction on the world market.
No-one wished to purchase one, regardless of its technical superiority and the supply of luxurious fittings no different car had, corresponding to reclining rear seats with built-in therapeutic massage programs, and doorways that opened and closed electronically on the contact of a button. Nonetheless in manufacturing, the Toyota Century is the car that’s used to move each the Japanese Emperor Naruhito and the previous Prime Minister of Japan, Shinzō Abe.
It wasn’t the cash that stopped those that might afford it from shopping for a Toyota Century (the present mannequin will set you again greater than AU$250,000), it was the badge on the bonnet. As a result of anybody might personal a Toyota, it appears that evidently the wealthy didn’t need to be seen in a single. Motoring fans didn’t need to be seen in a single both. Think about if, when requested what kind of unique car they drove, they needed to reply “a Toyota”.
So what did Toyota do? It began constructing luxurious autos that didn’t have the Toyota badge on them, however one other one. That identify?
You recognize it already: Lexus. They usually bought like scorching truffles (and nonetheless do), as a result of, fairly frankly, not everybody can personal a Lexus.
Which brings us to Rotel.
Initially of the hi-fi period, within the 70s, Rotel was by far and away the best-selling hi-fi part producer in Japan and, certainly, most likely the best-selling hi-fi model proper around the globe, with a well-deserved status for delivering fine quality at cheap costs.
Nonetheless, as an increasing number of producers entered its explicit area of interest within the hi-fi market, Rotel’s market share diminished, in order that within the early 90s, the corporate determined to begin constructing high-powered, high-performance ‘luxurious’ fashions to compete in opposition to the likes of Luxman and Accuphase in its house market, and in opposition to the likes of McIntosh and Audio Analysis on the world stage.
The fashions it constructed had been undeniably fabulous and had been definitely fully completely different visually from all different Rotel merchandise, exemplified by the looks of the RHC-10 preamplifier and RHB-10 twin mono energy amplifier, to call however two. The corporate additionally discovered from Toyota’s advertising fake pas and branded the fashions ‘Michi’, which is usually translated from the Japanese as which means ‘Righteous Approach’. However as a substitute of leaving it at that, it marketed the model as ‘Michi by Rotel’. You may guess the remainder.
This time round, twenty years into a brand new century, the Michi model identify is simply ‘Michi’, the advertising is for ‘Michi’ and the model writ giant on the entrance panels can be simply ‘Michi’. It’s provided that you look across the again that you just’ll discover small lettering that claims ‘By Rotel’. “Michi is taking Rotel’s values of wonderful efficiency and worth into the high-end phase with fashions that provide new ranges of engineering, construct and design whereas setting new reference requirements for audio efficiency,” says managing director Peter Kao. “We’ve got used all of our 55 years of design and manufacturing expertise to create our best-ever merchandise.”
Michi S5 preamplifier
The entrance panel of the Michi S5 Management Preamplifier’s austere exterior, with its black glass plate and two giant rotary controls offers completely no clue as to the complexity of what’s inside it… no less than it doesn’t till you turn it on and its good full-colour OLED panel springs into life.
Then, for those who spin the left-most management to see what sources is likely to be on supply, you’ll uncover that the P5 has no fewer than six line stage inputs, 4 of that are unbalanced (by way of RCA inputs) and two of that are balanced (by way of XLR) plus a single phono enter which you’ll be able to swap between being best suited for both moving-coil or moving-magnet cartridges.
On the digital aspect, you get six SPDIF inputs, three optical and three coaxial, in addition to USB and Bluetooth. Curiously, there is no such thing as a AES/EBU enter.
The Michi S5’s in depth menu system permits homeowners refined customisation choices for all inputs, so you possibly can swap off those you’re not utilizing so that they don’t seem if you’re scrolling via inputs, rename any or the entire inputs to extra precisely replicate no matter part you’ve related to them, plus you should use the Michi’s bass and treble controls to make particular tonal modifications connect to the particular enter you’re utilizing.
It’s also possible to repair a particular quantity stage to every enter that can override every other quantity setting and can’t itself by modified utilizing the entrance panel quantity management or the infra-red distant management’s up/down buttons. Michi says of this function: “That is helpful for enter sources that embody their very own quantity setting like frequent Apps on telephones or tablets.”
Look across the rear of the amplifier and also you’ll discover some further digital connections, however the community port is just for firmware updates and management over IP, and that USB-A socket is barely there to energy exterior gadgets. It has no digital sign functionality. The RS232 connector is there, in fact, to facilitate customized set up integration.
Additionally on the rear panel are six pairs of stereo line outputs, labelled ‘Line Out’, ‘Mono Sub Out’, ‘Pre Out1’ and ‘Pre Out2’, ‘Balanced Out1’ and ‘Balanced Out2’. The ‘left’ and ‘proper’ subwoofer outputs are usually not stereo: because the labelling suggests, every one outputs a summed sign derived from each channels. You additionally get two digital outputs, one coaxial and the opposite optical.
The USB enter helps 16-bit and 24-bit PCM from 44.1kHz as much as 384kHz in addition to DSD64 and DSD128, however to do that by way of a PC, you’ll must load a Home windows Driver, which Michi helpfully provides on a USB stick. Mac customers, in fact, don’t want a driver: their computer systems will simply work correctly with the Michi. The SPDIF inputs assist 16/24 PCM as much as 192kHz. Digital decoding is completed utilizing an AKM4490EQ 32-bit/768 kHz twin DAC, the most effective of the presently obtainable gadgets.
Whereas Rotel gear was as soon as manufactured in Japan, like the nice majority of Japanese hi-fi producers (and plenty of different hi-fi producers around the globe), it’s now manufactured in China, and the identical is true for parts bearing the Michi identify. Nonetheless, Rotel retains a degree of distinction from most producers as a result of it owns its personal manufacturing unit in Zhuhai in China, which it established in 2005. Rotel says that though Michi parts are manufactured at that very same facility, they’re made in a separate part of one of many factories.
Michi P5 energy amplifier
Me saying earlier on that the entrance panel of the Michi S5 was austere doesn’t depart me a lot to say concerning the Michi P5 stereo energy amplifier’s entrance panel as a result of, as you possibly can see for your self, it’s much more umm… austere.
There’s only a single button on the backside centre of its entrance panel, which is definitely a standby energy swap, for the reason that predominant energy swap is on the rear panel. Since energy amplifiers devour a variety of energy even after they’re not getting used, and significantly so within the case of the Michi P5, which is rated with an influence output of 500-watts per channel into 8Ω, you possibly can select to have the Michi P5 swap itself off routinely after a no-signal interval of 20 minutes, 1, hour, 2 hours, 5 hours or 10 hours. Alternatively, you possibly can disable the automated power-down circuit fully so it by no means switches off.
As with the S5, the P5 has a really shiny OLED show whose major function is its capability to behave as a spectrum analyser, exhibiting the spectrum of the music being performed in your alternative of 8, 12 or 16 bands, or you possibly can select to have the show act as a VU meter, for which there are 4 completely different choices (VU/x2/x4/x8). For both setting you possibly can select between 4 completely different brightness ranges, or you possibly can select to change the show off solely.
The show additionally exhibits the enter voltage on the prime proper of the show and the temperature of the heatsinks on the prime left. The voltage proven on the show (240V) didn’t truly replicate the mains voltage in my house on the time, which was 244V, so it’d simply present the meant working voltage, reasonably than the precise voltage being delivered to the amplifier.
Being an influence amplifier, all of the motion is across the rear, and it is best to be capable to see from the {photograph} that the Michi P5 has two units of inputs, one balanced (XLR) and the opposite unbalanced (gold-plated RCA). The rocker swap that selects which of the 2 can be energetic is positioned above them, with a community port and RS232 to its left, and 12V set off inputs and outputs to its proper.
There are two pairs of high-quality speaker terminals which are colour-coded and have collars that make it very straightforward for the knobs to get a grip on naked wire, plus you can too use banana plugs. In a extremely welcome transfer, the knobs are fully detachable, so you should use ultra-secure insulated eye terminal terminations in your speaker cables for those who like.
As you may need guessed from the scale of the Michi P5’s chassis, the rated energy output into 4Ω (800-watts) and the comparatively restricted quantity of heatsinking – together with the truth that the heatsinks are lined by a protecting layer of aluminium – the output gadgets are fan-cooled, for which function there are two giant (90mm diameter) holes in both aspect of the rear panel.
These holes are the exits for air-cooling ducts on the different finish of that are positioned ultra-quiet, low-speed followers that swap on when the output transistors attain a temperature of 39°C. These followers are so quiet that after they’re working you’ll solely be capable to hear them by placing your ear as much as the duct exit, and even you then’ll hear solely a really comfortable sound; one which sounds uncannily as if somebody is exhaling softly via their absolutely opened mouth.
As for these output transistors, there’s fairly a couple of of them to be cooled – 32 of them, in reality. The facility delivered to them points from a pair of two.2kVA transformers made in-house by Rotel itself. This isn’t stunning, as a result of Rotel has been making its personal mains energy transformers for a few years. What’s reasonably stunning is that the 4 47,000µF capacitors linked (two every by way of regulators) to every of those transformers are made within the UK.
I say “stunning” as a result of Rotel can be well-known for making its personal capacitors, however its web site knowledgeable me that it “at all times sources the most effective capacitor for every particular utility”, which signifies that within the case of its Michi parts, it makes use of slit-foil and T-Community electrolytic capacitors from the UK; Rubycon electrolytic capacitors from Japan; and LCR polystyrene capacitors from Wales. The built-in circuits come from Analog Units, Texas Devices and Burr-Brown, firms which are all domiciled within the USA.
Can I warn you prematurely to not try to raise – and even manoeuvre – a Michi S5 by yourself? Its dimensions (485x238x465mm) would make it a clumsy raise at the most effective of occasions, however it doesn’t matter what its dimensions, its lifeless weight of 60kg would make it inconceivable… except you’re an Olympic weightlifter.
Efficiency
Somewhat unusually as of late, Michi contains interconnects with its parts. I say “unusually” as a result of most producers attempt to cull favour with their retailers by not together with interconnects, so these retailers could make further revenue by including interconnects to the sale.
Whereas I’ve to admire Michi for doing this, the standard of the interconnects it provides would have me asking my pleasant retailer what different interconnects he may need obtainable. The standard is, nevertheless, a moot level, as a result of Michi offers solely unbalanced interconnects, and given the selection between utilizing balanced or unbalanced connectors to hyperlink a pre-amplifier with an influence amplifier, I’d select balanced connectors each time, so meaning I’d must spring for balanced interconnects anyway.
Every part comes with its personal distant management, however the two are similar, so you possibly can maintain one for a spare. The remotes are of extraordinarily prime quality and really engaging. If solely Michi had seen match to provide high-quality name-brand alkaline (and even lithium) batteries to put in in them reasonably than those it does present. I didn’t likelihood it, and used my very own Eveready batteries as a substitute. Why Eveready? As a result of the corporate ensures that its batteries won’t leak, and a distant management will be ruined by a leaking battery as, to my chagrin, I as soon as found.
Each models not solely have similar distant controls, these controls additionally use similar infra-red distant codes. This has the benefit that the identical distant sign turns each models on and off, and adjusts show brightness, for instance. However on this case it additionally introduces a curious quirk in order that if you’re utilizing the distant to inform the P5 to do one thing, the identical distant sign will inform the S5 to do one thing fully completely different… which can be, for instance, to change the show from spectrum evaluation to VU.
Since any modifications applied on the P5 by this behaviour are fully benign (i.e. they’ve completely no have an effect on on the amplifier’s sound high quality or its efficiency or, in reality, something that might have an effect on the music taking part in on the time) I didn’t fear about it and simply regarded it as a quirk. Nonetheless, for those who’re significantly bothered by it, you possibly can simply obscure the P5’s IR receiver so it couldn’t obtain the sign.
Set-up is sort of intuitive, so you might be unlikely to have purpose to have recourse to both of the 2 Homeowners’ Manuals, however for those who do you’ll be happy to search out that they’re well-written, well-illustrated and extremely informative. Throughout set-up please resist the temptation to position the P5 on prime of the S5, regardless of the apparent bodily and visible temptations to take action. Each gadgets will return higher efficiency in the event that they’re positioned aspect by aspect, or one above the opposite on separate racks of a correct hi-fi part shelving system.
My overview models had been clearly comparatively new, so I made positive to burn them in repeatedly for a number of days utilizing pink noise at comparatively excessive quantity to take action, avoiding any sonic annoyances by wiring one of many two audio system out of section then going through it straight in entrance of the opposite loudspeaker so nearly the whole lot cancelled out. (If you happen to haven’t ever tried this, it’s not solely an ideal burn-in assist, but additionally an ideal get together trick!)
After the lengthy wait I used to be fairly keen by the point the listening classes had been scheduled and I’m right here to inform you it was nicely definitely worth the wait. The sound was completely enthralling, completely life like and fully charming.
I knew I used to be in for a deal with as a result of there was no must acclimatise myself to something or work my approach into the listening session. Proper from the outset it was all simply vast smiles and toes a-tapping and permitting tracks to play proper via, reasonably than switching to different tracks to judge completely different areas of efficiency.
The results of all this was that I spent reasonably extra time listening to the Michis than I actually ought to have given the time constraints concerned in getting ready a overview for this situation, however there have been no complaints from me. If the Michis had been performers, I’d will surely have been on my toes calling for an encore.
This similar excessive stage of efficiency proved true for no matter enter I used, as a result of the Michi P5’s digital and phono phases are actually glorious. If you happen to’re a real vinylista you’ll need to use an exterior phono stage that permits better precision with cartridge matching than the P5’s ‘one enter matches all’ phono stage, however for those who play vinyl solely irregularly, I believe you’ll be more than pleased with the sound of the phono stage… I definitely was. I couldn’t fault the digital inputs both, whether or not I used SPDIF or USB. They’re so good that there can be completely no must spend money on an exterior DAC except you’re a type of audiophiles that really likes fidgeting with completely different filter settings and oversampling charges. So full marks to Michi right here as nicely.
What did I discover so enthralling concerning the sound? The whole lot actually. However general, I’d must say that what’s most spectacular is the totality of the very actual and tangible feeling {that a} musical occasion is happening proper there in your personal room. The sonic presentation is so vigorous and so true-to-life it’ll take your breath away.
And for those who’re into attempting to realize true-to-life listening ranges, then the Michi S5 is amongst these only a few amplifiers that can be capable to realise this for you effortlessly, with out stress, with out distortion, with out impacting in your mains energy invoice… and with out its chassis turning into so scorching it’s good to wreck the atmosphere by turning on the air-conditioning.
That stated, the Michi S5’s chassis can turn into heat for those who work it very, very onerous, so do give it some room to breathe, however that stated, I discovered that it runs far cooler than most amps of its ilk.
‘Large’ can be the most effective descriptor for the bass I heard from this Michi combo, however it was on the similar time delicate and tuneful. I can consider no higher demonstration of those twin virtues than to recommend that you just hearken to the tympani within the second motion of Beethoven’s Ninth, the well-known Choral Symphony.
Sure, their sound is impactful, spectacular and thunderous, however many high-end amplifiers can do that. What most can’t do is reveal that there’s solely two being performed, or that they’re tuned an octave aside. However utilizing this Michi duo, I might hear this immediately… and that’s a metric I’d name not simply revealing, however a revelation.
But when the Michi’s capability to disclose trivia within the bass areas is spectacular, its capability is equally spectacular throughout the midrange… if no more so. And if you wish to test the midrange capability of any part, the most effective albums to make use of is the one which debuted Chick Corea on electrical keyboard but additionally has two of my favourites, Joe Farrell and Flora Plurim. Regardless of being recorded in 1972 (or maybe due to it), the recording is stunningly good, whether or not it’s Plurim’s wealthy scat singing or the readability with which Corea’s staggeringly lyrical electrical piano taking part in is revealed, and the Michis revealed the whole lot with crystal readability.
On this album, you possibly can actually hear how an amplifier’s capability to ship air within the midrange aids one’s capability to listen to a number of devices clearly, regardless of how intently they compete for house. Whereas I believe that lots of the once-revered jazz fusion albums now sound dated, ‘Return to Ceaselessly’ sounds as if it might have been recorded yesterday.
The Michis’ high-frequency efficiency didn’t disappoint both. I’m typically an ideal fan of Ludovico Einaudi (although maybe not of his extra minimalist stuff) and his album ‘Components’ from 2015 is one among my favourites for testing the acute highs, and most significantly the second monitor, Night time. Simply hearken to that ethereal opening synth because it loops after which the best way Einaudi layers all the opposite sounds over it. The stabbing piano notes are interjected on the good moments. It’s an ideal instance of why timing is the whole lot, and why component-chain timing is essential for an genuine high-fidelity listening expertise.
Nice stereo separation and sumptuous stereo imaging are essential to tricking the ear and the mind into imagining the reproduced sound is ‘stay’, and the Michis demonstrated each to perfection when replaying Canadian chanteuse Holly Cole’s Prepare Track, from her 1995 Tom Waits tribute album ‘Temptation’. Though it’s additionally an ideal tester of bass, I favor to make use of the myriad sounds of Cyro Baptista’s tinkly percussion to judge high-frequency copy, stereo imaging and, for amplifiers, channel separation. And what I heard from the Michis was nearly as good as I’ve ever heard from any pre/energy combo. Bravo!
Last verdict
You might want to see the Michi P5 and M5 within the flesh to see how beautifully they’re constructed. Phrases can’t actually start to explain that. However you additionally want to listen to for your self how music that’s performed via them sounds, as a result of phrases can’t even start to explain that… although for those who began off by saying “completely and fully pure”, you’d be off to an excellent begin.
This Michi P5/S5 combo will get it proper. Actually nails it, in reality. If you need attractiveness, insanely excessive energy output, low noise, excellent efficiency and, most significantly, nice sound, you’ve arrived at your vacation spot.
Laboratory take a look at report
Earlier than going into element concerning the outcomes of Newport Take a look at Labs’ take a look at outcomes, it’s extraordinarily necessary to notice that for the needs of this take a look at, Australian Hello-Fi specified that every one assessments needed to be carried out with each the Michi S5 and Michi P5 within the ‘take a look at loop’. Subsequently there are only a few outcomes that may be in contrast with Michi’s personal specs, that are gained by testing the parts individually, or certainly in opposition to the outcomes from every other audio take a look at laboratory that has not examined the 2 amplifiers as a ‘combo’.
It signifies that, in impact, we’re reporting ‘worst case’ outcomes as a result of for outcomes corresponding to distortion, the inherent distortion of the Michi S5 are right here added to that of the Michi P5, which clearly doesn’t happen if the parts are examined individually.
One of many few outcomes that will not change is energy output, in fact, and Newport Take a look at Labs measured the facility output of the Michi S5 at 612-watts per channel (27.8dBw), each channels pushed into 8Ω, when it was delivering a 1kHz take a look at sign. It was additionally capable of ship this very same energy when delivering a 20Hz take a look at sign.
Nonetheless, when Newport Take a look at Labs used a 20kHz sign to check energy output, the Michi P5’s safety circuitry kicked in when the output voltage reached 45 volts RMS, which is round 253-watts (24.0dBW) into 8Ω, and round 506-watts (27.0dBW) into 4Ω. The truth that the safety circuit kicked in was not a shock in itself, as a result of 20kHz is a really excessive frequency to make use of for testing energy output, and the facility spectrum of music is such the Michi P5’s rated output energy (500-watts into 8Ω) would by no means be required at this frequency.
However as a result of the safety kicked in slightly sooner than we anticipated, we checked with Michi, which instructed us: “The S5 has been engineered and examined for steady energy output of 20Hz–20kHz however as you seen we now have safety circuitry to watch what is taken into account irregular working circumstances together with brief circuit, d.c. voltage on the outputs and over-current. As regular operations wouldn’t sometimes have a sign of this kind (frequency/energy) we do shut down the unit into safety at excessive energy outputs at excessive frequency. We discovered it greatest apply to watch and use an abundance of warning with the facility output generated by the S5.”
When Newport Take a look at Labs examined the facility output of the Michi S5 into 4Ω masses, the identical safety circuitry kicked in with 20kHz take a look at indicators, however the Michi S5 simply delivered 1052-watts (30.2dBW) per channel with 1kHz take a look at indicators, each channels pushed into 4Ω and 1,024-watts (30.1dBW) per channel with 20Hz take a look at indicators (each channels pushed into 4Ω). These impartial laboratory take a look at outcomes at 1kHz and 20Hz present energy output ranges which are nicely above Michi’s energy output specification for each masses.
It also needs to be famous that if Newport Take a look at Labs had examined dynamic (short-term) energy output, the Michi S5 would have delivered its rated energy output, as a result of the take a look at sign used for this function is so short-term that it might not have triggered the safety circuitry, however the Australian amplifier energy measurement normal specifies that the facility output of excessive constancy audio amplifiers have to be measured (and acknowledged) on a steady, reasonably than a dynamic foundation.
Frequency response is one take a look at that will surely be impacted by measuring each the P5 and S5 as a combo, but as you possibly can see from the tabulated outcomes, the Michi combo delivered superlative efficiency, with Newport Take a look at Labs measuring a response of 5Hz to 480kHz –3dB. The Michi combo’s frequency response throughout the audio band, which is proven in Graph 7, was measured as 20Hz to 20kHz ±0.18dB, which is self-evidently a wonderful outcome.
The frequency response measured when the Michi S5 was driving a take a look at load that simulates the load that will be offered to it by a typical hi-fi loudspeaker system is proven by the black hint on Graph 7, under.
You may see that it tracks the response gained with a non-inductive load nearly completely, which exhibits that the Michi S5 will sound the identical it doesn’t matter what audio system you hook up with it, and also will be capable to completely management the back-emf from audio system which have giant bass drivers. Though the Michi S5’s damping issue was greater than can be required by any speaker system, it’s not overly excessive, with Newport Take a look at Labs reporting it as DF61, on the again of an output impedance (at 1kHz) of 0.13Ω.
Channel separation was excellent at low and midrange frequencies, as proven within the tabulated outcomes, with the Michi mixture returning take a look at outcomes of 105dB at 20Hz and 98dB at 1kHz. The 72dB outcome at 20kHz is great, and greater than will ever be required with the intention to ship good stereo imaging and separation, however slightly wanting what I may need anticipated.
Nonetheless, this might simply have been influenced by the place the amplifiers had been positioned on the take a look at bench relative to one another, in addition to by the interconnects connecting the 2, so even-better outcomes is likely to be achieved beneath completely different circumstances. The identical could possibly be stated for the inter-channel section outcomes, despite the fact that these, too, are actually glorious outcomes.
Channel stability was amazingly good. Taken merely on its worth of 0.019dB, no-one would ever have guessed this could be the results of testing a pre/energy mixture; It’s extra such as you’d get by testing a state-of-the-art stereo energy amplifier by itself. This can be a excellent achievement by the engineers liable for designing the Michis.
Newport Take a look at Labs measured the A-weighted signal-to-noise ratio of the Michi P5/S5 mixture as 76dB referenced to an output of 1-watt, and 103dB referenced to rated output. The 103dB result’s glorious, however additional means that the outcome at 1-watt, though good, could possibly be additional improved by cautious part placement and interconnect routing.
Graph 1 exhibits the whole harmonic distortion measured by Newport Take a look at Labs when the Michi combo was delivering 1-watt into an 8Ω load. You may see there’s a second harmonic part at –95dB (0.00177%) and a fourth harmonic at –110dB (0.00031%) and that’s it: in any other case the noise flooring above the elemental is completely clear, and in addition sitting proper down at –115dB (referred to one-watt). This is a superb outcome, as each harmonics are harmonically associated to the elemental, which can guarantee good sound.
Graph 2 exhibits the whole harmonic distortion measured by Newport Take a look at Labs when the Michi combo was delivering 1-watt right into a 4Ω load. You may see the second harmonic part has elevated barely, to –88dB (0.00398%), and the fourth to –112dB (0.00025%) plus a 3rd harmonic has appeared at –108dB (0.00039%) and a fifth at –113dB (0.00022%). As soon as once more, that is glorious efficiency.
Graph 3 exhibits the whole harmonic distortion measured by Newport Take a look at Labs when the Michi combo was delivering 20-watts into an 8Ω load. As you’d have anticipated given the rise in energy output, further distortion parts have been launched, however the important construction of the lower-order parts is maintained, with the second harmonic part at –93dB (0.00223%), the third at –110dB (0.00031%), the fourth at –112dB (0.00025%) and the fifth at –115dB (0.00017%).
The distinction within the visible look of the graph is because of the noise flooring of the amplifier having dropped all the way down to round –130dB, which speaks for itself.
You may see that the noise that contributed to the general outcome talked about beforehand and tabulated within the outcomes is low-frequency in nature, as evidenced by the spikes on the excessive left of the graph.
Graph 4 exhibits the whole harmonic distortion measured by Newport Take a look at Labs when the Michi combo was delivering 20-watts right into a 4Ω load.
Primarily the distortion parts are the identical as when driving an 8Ω load, however curiously, there’s a slight enhance within the noise flooring. This, along with the one-watt outcomes, would appear to recommend it is best to favor 6Ω or 8Ω designs when selecting loudspeakers to companion with the Michis.
CCIF-IMD distortion (19kHz and 20kHz take a look at indicators at equal ranges) into an 8Ω load is proven in Graph 5. As you possibly can see, there’s nothing to be seen in any respect. Sensational efficiency! Not solely are there not any of the side-bands across the high-frequency take a look at indicators I usually count on to see, there’s additionally no signal in any respect of a regenerated distinction sign down at 1kHz.
When Newport Take a look at Labs used the identical CCIF-IMD take a look at sign, however elevated the facility output to 20-watts (Graph 6, above), each the aspect bands and the regenerated sign had been launched into the output, however at very low ranges: round –90dB (0.00316%) for the 2 major aspect bands at 18kHz and 21kHz, and at round –105dB (0.00056%) for the regenerated sign. As soon as once more, these are all outstandingly good outcomes.
The tone management motion of the Michi P5 is proven in Graph 8. You may see the bass management delivers round 11dB of increase that’s properly shelved at 20Hz, then rolls off under this, which is great design. It delivers reasonably extra lower: round 17dB. This similar graph additionally exhibits the motion of the treble management, and you’ll see it gives 9dB of increase that cabinets properly at 20kHz. Once more, that is glorious design.
As with the bass management, the treble management gives reasonably much less high-frequency attenuation, however nonetheless a more-than-adequate 13dB at 20kHz. If you happen to attenuate each bass and treble additionally, you will scale back the general quantity barely throughout the midrange, however that is of no import, because it could possibly be simply corrected by rising the amount barely.
The Michi combo’s distortion on the S5’s rated energy output (500-watts per channel into 8Ω) is proven in Graph 9. As soon as once more, Michi’s engineers have excelled themselves, with distortion fully beneath management, such that the second-order part is at 93dB (0.00223%), all of the even-order parts are greater than 100dB (0.001% down, and all of the odd-order parts are greater than 120dB down (0.0001%).
All these distortion parts are too low in stage to be audible, however even when they had been, even-order distortion is agreeable to the ear, so it wouldn’t be a difficulty. Notice on this graph that the noise flooring proper throughout the audio spectrum is now down at –140dB, and even the low-frequency noise on the left of the graph, which is greater in stage, remains to be greater than 110dB down. As soon as once more, glorious efficiency.
Sq. wave testing utilizing a 100Hz sq. wave revealed what the frequency response already confirmed, with the lean on the waveform indicating the Michi combo’s frequency response rolls off at low frequencies and doesn’t prolong to d.c. The slight curvature within the tilt additionally exhibits a tiny quantity of group delay.
The overshoot on the vanguard exhibits that there’s a rise within the Michi’s frequency response at an ultrasonic frequency. Additional investigation into this by Newport Take a look at Labs revealed that the rise was 3dB, and that the frequency of the height was at 302kHz. That is fascinating, and clearly measurable, however can have zero have an effect on on the amplifier’s sound high quality.
The 1kHz sq. wave exhibits the identical h.f. overshoot, and a few slight tilt on the horizontals, so it’s not an ideal outcome, however it’s so near good as actually doesn’t matter.
The 10kHz sq. wave’s horizontals are then again, completely flat, and the rise-time is super-quick, so if it weren’t for the overshoot attributable to the high-frequency rise to 302kHz, it might be an ideal outcome.
Newport Take a look at Labs determines amplifier stability by putting a 2µF capacitor in parallel with an 8Ω load and driving the amplifier into this load utilizing a 1kHz sq. wave because the take a look at sign. As you possibly can see from the oscillogram, the Michi was superbly behaved, with only a quarter wave top overshoot that was fully damped inside three cycles, so I can say that the S5 can be fully steady into even probably the most extremely reactive loudspeakers.
When each models are in standby mode, they may nonetheless draw 2.41-watts out of your mains energy provide, which is reasonably greater than the Australian Authorities’s mandate for standby energy consumption, however low sufficient that it might have nearly zero impact in your utility invoice.
If you’re utilizing this Michi combo to hearken to very loud music, the 2 will pull someplace round 200-watts out of your energy provide, which is surprisingly modest contemplating the S5’s energy ranking. Mixed energy issue was measured at +0.627.
Total, Newport Take a look at Labs measured outstandingly good efficiency from this high-powered, low-distortion pre/energy mixture.
