Rotel Michi S5 power amplifier Measurements

Sidebar 3: Measurements

I measured the Rotel Michi S5 with my Audio Precision SYS2722 system, preconditioning the amplifier by operating it at 1/8 the specified power into 8 ohms for 30 minutes. At the end of that time, the top panel's temperature was 86°F/30°C, and that of the side panels next to the heatsinks 101.1°F/38.4°C. Though the rear-panel fans had turned on and were venting hot air, they were silent.

The Michi S5's voltage gain at 1kHz into 8 ohms was 23.6dB for the balanced input and 27.7dB for the unbalanced input, both values close to the specified gains. Both inputs preserved absolute polarity, ie, were noninverting. The single-ended input impedance is specified as 12.5k ohms. I measure 12.7k ohms at low and middle frequencies, decreasing inconsequentially to 11.7k ohms at the top of the audioband. The balanced input impedance, specified as 100k ohms, was 94k ohms at 20Hz and 1kHz, 88k ohms at 20kHz.

The S5's output impedance (including the series resistance of 6' of speaker cable) was low, at 0.07 ohm at 20Hz, 0.12 ohm at 1kHz, and 0.135 ohm at 20kHz. As a result, the variations in the Michi S5's small-signal frequency response into our standard simulated loudspeaker response (fig.1, gray trace) were inconsequential. Into resistive loads (blue, red, cyan, magenta, and green traces), the amplifier gently rolled off well above the audioband, the –3dB frequency dependent on the load. The response into 2 ohms (green trace) was down by 3dB at 85kHz. The Michi S5's reproduction of a 10kHz squarewave into 8 ohms (fig.2) featured very short risetimes and no overshoot or ringing.

622MichiS5fig01

Fig.1 Rotel Michi S5, balanced frequency response at 2.83V into: simulated loudspeaker load (gray), 8 ohms (left channel blue, right red), 4 ohms (left cyan, right magenta), and 2 ohms (green) (1dB/vertical div.).

622MichiS5fig02

Fig.2 Rotel Michi S5, small-signal 10kHz squarewave into 8 ohms.

The Michi's channel separation (not shown) was very good, at >80dB below 2kHz and still 64dB at the top of the audioband. The unweighted, wideband signal/noise ratio (ref. 1W into 8 ohms and measured with the unbalanced input shorted to ground) was also very good, measuring 79.5dB (average of the two channels). This ratio improved to an excellent 88.7dB, left channel, and 85.7dB, right, when the measurement bandwidth was restricted to 22Hz–22kHz, and to 92.1dB, left, and 89.7dB, right, when A-weighted. Spectral analysis of the low-frequency noisefloor while the Michi S5 drove a 1kHz tone at 1Wpc into 8 ohms (fig.3) revealed that although some AC-related spuriae were present, these all lay at or below –90dB.

622MichiS5fig03

Fig.3 Rotel Michi S5, spectrum of 1kHz sinewave, DC–1kHz, at 1W into 8 ohms (left channel blue, right red; linear frequency scale).

The Michi S5's maximum continuous power is specified as 500Wpc into 8 ohms (27.0dBW) and 800W into 4 ohms (26.2dBW). With our usual definition of clipping as being when the THD+noise reaches 1%, I measured a clipping power with both channels driven into 8 ohms of 570Wpc (27.56dBW, fig.4). Even though the wall voltage had dropped from 119.1V to 115.4V with both channels clipping into 4 ohms, the Michi S5 still easily exceeded its specified power into that load, the maximum power measuring 940Wpc (26.72dBW, fig.5). As the S5's manual says that 4 ohms is the recommended minimum load impedance, I didn't test the clipping power into 2 ohms.

622MichiS5fig04

Fig.4 Rotel Michi S5, distortion (%) vs 1kHz continuous output power into 8 ohms.

622MichiS5fig05

Fig.5 Rotel Michi S5, distortion (%) vs 1kHz continuous output power into 4 ohms.

Fig.6 shows how the percentage of THD+noise varies with frequency into 8 and 4 ohms at 20V (equivalent to 50W into 8 ohms and 100W into 4 ohms). The THD was very low at low and middle frequencies, though a little higher in the right channel (red and gray traces) than the left (blue and green). It rose in the top three audio octaves, this presumably due to the amount of corrective negative feedback reducing with increasing frequency.

622MichiS5fig06A

Fig.6 Rotel Michi S5, THD+N (%) vs frequency at 20V into: 8 ohms (left channel blue, right red) and 4 ohms (left green, right gray).

The distortion signature into 8 ohms was predominantly the second harmonic (fig.7), though when I examined the spectrum with 50Hz at a level of 100Wpc into 8 ohms (fig.8), this harmonic was lower in level than the AC supply–related spuriae. Repeating the spectral analysis with a 1kHz signal at the same voltage into 8 ohms (fig.9), the second harmonic lay at –89dB (0.003%), the third harmonic was negligible, and the fourth harmonic lay at –97dB (0.0014%). Despite the decreasing linearity at high frequencies seen in fig.6, the Michi S5 performed well when driving an equal mix of 19 and 20kHz tones at 50Wpc into 8 ohms (fig.10). Both the 1kHz difference product and the higher-order products at 18 and 21kHz were more than 90dB below the peak signal level.

622MichiS5fig07

Fig.7 Rotel Michi S5, 1kHz waveform at 50W into 8 ohms, 0.003% THD+N (top); distortion and noise waveform with fundamental notched out (bottom, not to scale).

622MichiS5fig08

Fig.8 Rotel Michi S5, spectrum of 50Hz sinewave, DC–1kHz, at 100Wpc into 8 ohms (linear frequency scale).

622MichiS5fig09

Fig.9 Rotel Michi S5, spectrum of 1kHz sinewave, DC–10kHz, at 100Wpc into 8 ohms (linear frequency scale).

622MichiS5fig10

Fig.10 Rotel Michi S5, HF intermodulation spectrum, DC–30kHz, 19+20kHz at 50Wpc peak into 8 ohms (linear frequency scale).

As with the Rotel Michi M8 monoblock that Michael Fremer reviewed in July 2021, the Rotel Michi S5 combines high power with a wide bandwidth, low noise, and very low, primarily even-order distortion.—John Atkinson

COMPANY INFO
The Rotel Co. Ltd.
US distributor: Sumiko
6655 Wedgwood Rd. N, Suite 115
Maple Grove, MN 55311-2814
(510) 843-4500
ARTICLE CONTENTS

COMMENTS
Anton's picture

Thank you.

georgehifi's picture

I may have missed it, but it's a shame no mention of what the output devices are, Mosfet or BJT (bi-polar).
The statement "high current" says they "could be BJT" and in the past Rotel in their bigger stuff did use BJT's, but then usually a 2ohm load shouldn't be problem to test into. Do you know JA?

Cheers George

Ortofan's picture

... of the bi-polar junction type.

For (peak/dynamic) output power test results performed at a load impedance lower than four ohms, refer to the lab report from Hi-Fi News.
https://www.hifinews.com/content/rotel-michi-p5s5-prepower-amplifier-lab-report

Long-time listener's picture

That sax solo in the middle of the title track, "Idle Moments," is aMAZing.

I'm sorry but I don't always understand your terminology. "The S5, in turn, sounded more transparent ... [but] never quite overwhelmed me with the detail and clarity the Progression M550s..."

What is the difference between "transparency" and "detail and clarity"?

Jason Victor Serinus's picture

Transparency refers to haze or lack thereof that can obscure space and silence between notes and dim / homogenize colors. In audiophile jargon, greater transparency is often equated with a blacker black. Think perhaps of the difference in sound and enjoyment between two loud venues, one with loud air conditioning and background noise and another dead silent. With greater silence, one can see deeper in the presentation.

Greater transparency can, of course, reveal greater detail and clarity. In a huge orchestral piece, greater detail can enable you to hear the complex harmonics of a cello or double bass. In vocal works, greater detail can refer to the undertones, overtones, and subtle shifts in dynamics and emphasis that distinguish fine artists from the truly great. Without the clarity that comes with a fast and focused presentation, instrumental lines may be smudged and bass boomy.

That's the best I can do at an hour past my normal bedtime. Hope it helps.

Long-time listener's picture

and the review.

T.S. Gnu's picture

…further clarification with the passage of time allowing you to have, hopefully, had some rest and rumination? It would aid in providing more insight to what you are attempting to communicate in your writing.

Regards

Jack L's picture

Hi

It came from the medieval Latin word: "tranparere"

"tran means through
"parere" means appear.

In phyics, transparent means transmitting heat or other electromagnetic rays without distortion.

In simple layman language, transparent means see-through or crytal clear.

That's what I always describe "transparent" as virtualizing the music performance reproduced like seeing crystal clear all details of it.
I would not want veiled transparency in my home music, decided substantially by the amplifiers being used there.

Jack L

DougM's picture

Anyone that lives in the City, and calls it Frisco, is certainly not a native, and deserves to be run out of town permanently

David Harper's picture

I was under the impression "transparency" refered to the sound of the recording absent any amplifier at all.

Jason Victor Serinus's picture

If a tree falls in the forest and there's no one there to hear it fall, does it make a sound?

T.S. Gnu's picture

On what one considers to be the definition of the term "sound" and considering we are still trying to figure out what you mean when you use the term transparency, let’s shelve this one for a while. (◔‿◔)

Regards

MatthewT's picture

Define "transparency" and we go from there? JVS' defintion is perfectly clear.

T.S. Gnu's picture

….when I write something that you read. And, likewise, I will ask you to do so when you write something that I read. If I am to understand what you (or the author), mean when you use ta term that can be construed in different ways, I need to get you (or the author) to define that term. I don’t have to agree, or disagree with your definition — and, indeed, I am doing neither in this case, nor do I see any need to do so. I merely need to know, unambiguously, what YOU (or the author) mean so that I can gain meaning from what is written.

His definition isn’t perfectly clear, as I have pointed out in a comment below his response to my query. It is self-inconsistent. Hence my request for further clarification.

Put another way, I could have responded by saying, “It doesn’t work that way” because:
1) if you (or the auhor) don’t agree with my definition, we are back to square one (in a similar manner to whether georgehifi and the author think their definitions are the same or different which is the point I am trying to clarify here), and
2) asking a writer to clarify what (s)he means isn’t the imposition that you make it out to be…unless, the author is unable define the terms used, which then…is a whole different problem, that I hope is not the case her and am giving the author every opportunity to assure us of.

I hope that this clarifies my rationale and intent which is simply, “I’m not sure I understand. What do you mean by what you said?” I am hoping to be able to, whether I agree with the definition provided or not, say, “Got it!" and read future articles with that understanding.

Jack L's picture

Hi

Yes, by conversation of energy, the kinetic energy of the falling tree will be transformed into thermal energy while landing on the ground + SOUND energy HEARD by live creatures nearby enough, but NOT heard BY "no one there to hear it".

Jack L

georgehifi's picture

To me "transparency in audio means.
As little as possible colouration/distortion, no noise, no dynamic compression and unlimited extension lf to hf.
In other words an "open window to the sound".

Cheers George

T.S. Gnu's picture

can be read to mean many different things, as just exemplified by DH and georgehifi [edited to correct name]. I am hoping that the author of The Fine Article responds to my query above here requesting clarification on what he meant so that readers can take away some consistent, unambiguous interpretation of what he is attempting to communicate. It would certainly be helpful to at least three people, possibly four if one includes the author. (◔‿◔)

Jason Victor Serinus's picture

Lo and behold, Stereophile has An Audio Glossary, devised by magazine founder J. Gordon Holt: https://www.stereophile.com/j_gordon_holt/50. There you can find this definition:

transparency, transparent 1) A quality of sound reproduction that gives the impression of listening through the system to the original sounds, rather than to a pair of loudspeakers. 2) Freedom from veiling, texturing, or any other quality which tends to obscure the signal. A quality of crystalline clarity.

I must disagree with part of George HiFi's assertion that transparency means "As little as possible colouration/distortion, no noise, no dynamic compression and unlimited extension lf to hf. In other words an 'open window to the sound.'" Coloration, for example, does not necessarily veil sound. Some systems are warmer than others, but both can offer crystalline clarity. Ditto for dynamic compression. To me, the essential component of transparency is the ability to hear silence between notes. There's a void - a blackness or absence - that enables colors to emerge.

The live event is inevitably colored by the acoustic. Put the same singer on the stages of the San Francisco War Memorial Opera House and Seattle's McCaw Hill, and listen from the 15th row of the orchestra and then from the front and rear of the top balcony. You'll get very different senses of how they sound. Neither the live event nor a recording offers, in and of itself, an open window to the sound. The former is colored by the acoustic, the latter by the will of the recording engineer. They are the final intermediaries. The goal of high-end audio is enable you to hear what the engineer intended you to hear (or, at the least, hoped you would hear.)

It's July 4. I hereby declare my independence from further discussion. As the Church Lady or whomever used to say on SNL, "Talk amongst yourselves."
https://www.youtube.com/watch?v=XVloHiUCKyg

T.S. Gnu's picture

You didn’t internalize it or refer to it when originally asked about YOUR definition of transparency, but instead answered in a vague manner. You invoke Holt’s definition but then follow it by effectively saying that colouration/distortion doesn’t veil sound. Then there are the gymnastics about a live event being coloured by the acoustic, and the recorded by the engineer.

Simply put, you are conflating the production of sound, with the REproduction of sound and appear to be unable/unwilling to see the difference between the two. Colouration (reverb/echo/harmonic distortion) added during the production of the music IS part of the original content. Your apparent confusion of this issue is rather disturbing to see. I say “apparent” because you later state that equipment should "enable you to hear what the engineer intended you to hear."

It is surprising that this has also slipped past the editor. Such a fundamental error, especially when proudly stated explicitly makes it very difficult for a reader to understand just what exactly you refer to when you in your attempts to characterize a piece of hardware that is designed to REproduce an input signal in a manner Holt refers to by (paraphrasing follows) simply making the “original sounds” louder without “obscure the signal.”

If one hews to Holt’s definition, as you claim to do, then your paragraph above your Declaration of Independence is, while being an entertaining encapsulation of thoughts, really not relevant (with the possible exception of the last sentence unfortunately obfuscated by your statements in your second paragraph.

Upon carefully reading all your responses, it appears you still haven’t actually answered the question “What is the difference between "transparency" and "detail and clarity"?” I say this, because if one carefully reads Holt’s definition he states that they are, pretty much, one and the same — especially point 2), which…seems to be pretty much what georgehifi said.

Regards

ken mac's picture

It seems this is the first time you've read "transparency" in an audio review. It's a common phrase. I suggest you read every Stereophile article found in this site going back to the early 1960s. Then you will understand such commonly used terms as "bass bloat," "transient snap," "midrange clarity," "extension," "dynamics," etc...Hope this helps.

T.S. Gnu's picture

I have, indeed, read the term oftentimes; it is a common phrase. The query directed at the august author of this piece arises from a response to Long-term listeners question, “ What is the difference between "transparency" and "detail and clarity"?‘ which ends with “That's the best I can do at an hour past my normal bedtime. Hope it helps.”

Your advise to "read every Stereophile article found in this site going back to the early 1960s" appears to be better directed towards the person making that comment, surely. I would also refer you To some of the very points I raised in my comment that you generously responded to, if that helps put things in context.

As Archimago below mentions quite succinctly, the term is generally agreed upon, and this discussion would have been much shorter (or never taken place at all) had the author simply responded so to the original query by Long-term listener.

Regards…and thanks for all the help (with due apologies to Douglas Adams)

Glotz's picture

Linda Richman.. Coffee Tawwwwwk. Mike Meyers was the actor.

Discuss.

And T.S. is tired and pedantic.

T.S. Gnu's picture

If asking for details makes me a pedant, then guilty as charged

Jack L's picture

Hi

Agreed!

Coloration is the sonic characteristic of an audio piece which can be see-thru transparent.

Typical examples are, IMO.

(1) compression horn loudspeakers - very transparent, minimum distortion yet got coloration of a horn. Even vocals, strings & woodwinds sound horny, IMO.

(2) moving coil cartridges - the stringy sound detailing like splitting hair colours whatever they track up. I just find it too articulated.

Colouration & tranparency are 2 different things, IMO.

Jack L

curbfeeler's picture

Coffee Talk with Linda Richman performed by Mike Myers on SNL.

David Harper's picture

Imaginative subjective descriptions of the sound of an amp seem delusional to me. Only my opinion. Amps are a relatively simple technology. Nothing magical about them. They pretty much all do the same thing with the rare exception of an incorrectly designed one.

Jason Victor Serinus's picture

Glad to see that Julian Hirsch of Stereo Review is alive and well.

Every amplifier or monoblock that has entered my system has sounded different and measured differently. The proof is in the listening.

JHL's picture

...of folks who have never heard the transparent window on the original performance venue - a common aspect of the audio high end familiar to hundreds of thousands - Harper just must opine. The difference is that having never heard it, he feels compelled again to call the other guy delusional. It's like a tic.

Funny, because that transparent window is just the refinement of stereophonic playback to the point that it becomes a visual sensation. It's the inevitable result of ... high end audio.

latinaudio's picture

With all due respect Mr. Harper, maybe you must have had or need only one equipment in your life. I'm on my fifth rig in 60 years and no amp I've owned has sounded the same. None do. My current amp is "Class A" according to Stereophile, clean, crisp, full bodied... but still behind others I've heard. Please go to a hifi store as soon as possible and ask to hear at least 2 amps. If you can't hear any difference and continues to state that your opinion is correct... don't waste your time reading this magazine. If you hear differences: start saving for a higher experience in your life.
Cheers!!!

David Harper's picture

I have deleted this post because it was dumb. My apologies.

johnnythunder1's picture

nasty and bitter one. You are the audio Taliban. you know better than everyone here. No one else knows what you know about audio. we are all idiots besides you for buying different amplifiers with supposedly different sounds.

JHL's picture

...in a space he's never visited, Harper is eminently qualified to tell you what you mustn't hear from gear he's never heard delivering sound he has no comprehension of.

And everything you know is wrong. So ends the lesson in objectivity.

johnnythunder1's picture

You're entitled to your opinion of course but most people would seriously disagree with you. That said, there are people who think all cameras take the same photo regardless of quality of lens, and that the folly of paying $50.00 for a bottle of wine is silly, that there is no difference between a 300 dollar wool suit and a $3000 dollar one. The differentiator here is the quality of the components in an audio chain and the time and R&D spent in experimenting etc. to get to an end result. And the TASTE of the designer. Just because you can't hear the difference and can't even accept that there can be a difference says a lot.

David Harper's picture

What you mean is you have imagined that every amp has sounded differently.
In fact they have not. Placebo is a powerful thing. More powerful than you are consciously aware of.I'm not just trolling here. The truth is important.
People should not be led to believe that overpriced high-end gear is worth their money. It isn't.

supamark's picture

Do you also believe sommaliers are suffering from the placebo effect? I think all wine tastes pretty much the same - like grape juice with vodka added, but I don't make the mistake of thinking my experience is the same as anyone else's and say anything more than a box of Boone's Farm is a waste of money. Just because you can't perceive the differences doesn't mean they don't exist.

Mark Phillips,
Contributor, Soundstage! Network.

Anton's picture

Please leave us oenophiles out of this BS.

Wine tasting and rating is often done in blind fashion. In audio that is anathema.

For reviewers, it seems the approach is: ‘to listen blind is to be found out.’

supamark's picture

It is the heightening of one sense through extensive training to achieve the necessary brain alterations (brain plasticity is wonderful). I got my "training" as a recording engineer. I mean sitting there for hours listening to the same thing over and over and over making tiny adjustments and listening to the changes until it's just right. Learning the sound of each EQ, compressor, reverb, etc. For years.

Blind listening isn't anathama, it's a pain in the ass that doesn't help describe how something subjectively sounds. We, like Stereophile, measure almost everything after the reviewer is done so you can see an objective view on the equipment. My job is to describe my subjective impression, in a way that's hopefully both informative and entertaining. If you want to check our work, go out and listen to the equipment yourself.

Mark Phillips,
Contributor, Soundstage! Network.

Anton's picture

"Blind listening isn't anathama, it's a pain in the ass that doesn't help describe how something subjectively sounds."

Just like open label wine reviewing is known to skew opinion based on knowing the wine in advance, humans suffer the same fate with listening that we do with tasting.

I don't mean this in a negative way....as a reader and fellow audiophile, I don't care if blind listening is a 'pain in the ass.' It's a pretty interesting phenomenon, especially getting away from the 'hearing what we expect to hear' paradigm. [I'm not one of those 'objectivists,' just interested in how precise a 'tool' I am. ;-D]

How big a pain in the ass would it be to have someone switch out a pair of interconnects without you knowing which ones you are listening to and see if your opinion persists?

Our local club does this sort of thing all the time, it can be an eye/ear opener.

We are curious about this sort of thing.

I would suspect all of us might have that curiosity, but maybe not.

Again, I'm not insisting on instantaneous DBT, blah blah blah....I just think we should always wonder what variability we bring to a situation.

On the plus side, imagine if someone were to be the "Interconnect Messiah" who can actually discern between cables in blind listening. That would be pretty epic. All the years of blind listening deafness would be washed away.

I'd like that.

supamark's picture

My "beat" is DACs and headphone amps, and a column about recording. When I reviewed the Cambridge DacMagic 200M I did something like what you suggest. It has three different digital filters with an easy way to switch them without looking. I suspect you can see where I'm going with this, I would look away and just start rapidly pressing the button to switch filters until I lost track. It helped that not every button press would advance to the next filter. Once I "learned" the sound of the filters I could reliably identify them blind. I had assumed they were the ones spec'd on the DAC chips, but Cambridge actually programmed their own (which is uncommon). I was a little surprised when I saw the impulse response measurements afterwards in/re my filter preferences.

The headphone amp I have in for review now sounds very different than what I expected *and* my reference Pass Labs HPA-1. It's the harmonic distortion, which the item under review claims to have very little of (I believe 'em), and the thing makes headphones sound like good studio monitor speakers instead of headphones - very weird and unexpected (and pretty cool). Also, based on sound, it *should* be bigger and weigh more than the Pass amp but it's less than 1/4 the size and 1/3 the weight.

I am not really into cables. FEP Teflon dielectric and a good connector are my main criteria. I don't like locking RCA plugs. The FEP dielectric requirement weeds out cheap cables, and it's a measurably excellent dielectric material. Now *that* is something that should be blind tested (dielectrics). You'd need a pretty large sample size and a DAC with multiple live outputs of the same type. And another person to decide which cable is "A" and "B" on a given day and hook them up so they're not visible. But it would be more experiment than review, and not exactly a gripping read.

Also, physically removing one pair of cables and inserting another would take too long to be experimentally useful in my experience. You have to power down the amp, swap out the cables, then power the amp back up. I've found that if I take more than a couple seconds to change headphone amps the differences start becoming less sharp very quickly, and that's a single "hot" cable pull/insert and comparing amps not cables.

Mark Phillips,
Contributor, Soundstage! Network.

MatthewT's picture

To be that closed-minded, but OTOH it must save you lots of money buying your gear at Walmart.

David Harper's picture

deleted post

MatthewT's picture

Arrogant and presumptuous. How could it be garbage if it is all the same? Eat your prunes and crap somewhere else, boomer.

Glotz's picture

Nailed him! lol..

If someone like David calls out that his gear is better... let's see a list of components from him to back up such statements and a brief description of where and when he bought said equipment.

Those that walk can talk.

johnnythunder1's picture

assumptions that you are being taken advantage of by rip off artists of all kinds. you know better. all amps sound the same. No difference at all. It's a large conspiracy of audio equipment engineers, retailers and reviewers working together to take our money. You're right. You know it all to make such grand assumptions despite the experts who know better.

Long-time listener's picture

It must be: Your belief that all amps sound the same is exerting a powerful placebo effect that keeps you from hearing, or even listening for, any differences. Placebo effects work in both directions my friend.

JHL's picture

...is that in this "delusion" he's always projecting on people he hasn't met about things he hasn't experienced and admittedly doesn't know, the joyless Harper - even with his amazing technocolorless stereo system, the one nobody knows anything about - can't account for the pattern of use experience that routinely has scores of users hearing the same sonic effects from the same component, then passing on that opinion among other listeners, to find they too heard it do the same thing.*

Here Harper, without a scant shred of evidence, postulates that not only is the sound of a thing somehow your delusion, but that it involves clairvoyance and the unique and odd phenomenon of reaching backwards and forwards in time to connect biases the way it logically must if this is all made-up.

That's the only explanation if you heard it, then a year later I heard it, and in the end we find that we agree how it sounds right down to the words.

Meanwhile the whole human experience routinely reports impressions of interfaces with nature. Audio is the only one where it's prohibited to the degree that the only way to account for it is mass psychosis with brain-to-brain activity spanning time itself...

*which is, of course, the gist of audio reviewing.

bhkat's picture

Interesting review. If calling it "Frisco" deserves running out of town, you probably don't want to know what we call it in the Midwest.

Jason Victor Serinus's picture

Are you suggesting that the midwest is homogeneous? Have you performed listening tests and public opinion polls to confirm that?

David Harper's picture

This is what I love about the internet. Everyone has an equal voice. No matter how stupid and uninformed they are. The lowest common denominator.

johnnythunder1's picture

stupidest comment I've read here recently (and it was tough competition.) Why are you here if you think all amps sound the same? This is Stereophile. Subjective audio reviews are what they do. Admit it - just to troll and sh-t on other's joy.

Anton's picture

Their job is to transmit an intact musical signal to our speakers, despite the designer never knowing which preamp or speakers will precede it in the chain or follow it after.

Looking at the variability of the pieces of the chain upstream or down makes me feel like amplifiers face a truly Herculean task.

No surprise at all that different amps sound different in different circumstances. Why would one think they don’t?

MatthewT's picture

Sound exactly the same. That you, Jack?

Glotz's picture

'that Jack L rages and spews upon.

Johnny allows for other voices to be heard (and I would think grows by discussing with these other voices).

Johnny is a fair, concise and funny poster and builds sound logical arguments throughout the years I've been in here.

PS- And David Harper is an excellent example of Lowest Common Denominator on the internet, esp. for someone in their 70's (and presumably very close to death).

Do you really feel after 50 years of listening as an audiophile that all amps sound the same? If so, turn in your 'lying badge of dishonor' please

johnnythunder1's picture

I appreciate that you have noticed. The feeling is mutual.

Jack L's picture

Hi

Stop your personal attack !

Your frequent incorrect comments make many here, including me, spew out bigtime !!!

Jack L

Long-time listener's picture

I have no doubt this amplifier sounds as good as the reviewer says, and that it's worth the money. But that raises a question in my mind. Why does Rotel's top-end stuff sound so good, at "reasonable" prices, while their entry-level stuff is frequently reviewed with adjectives such as "dry," "flat," etc., and rarely gets rave reviews (relative to similarly-priced gear from other companies)?

johnnythunder1's picture

a couple of years ago. The A11 Tribute integrated for approx. 1/10th of the price. It was worked on by Ken Ishiwata of Marantz fame. This Michi line seems to be engineered, designed and industrial design is at a way higher level than the standard Rotel line which is pretty generic stuff. NAD similarly has basic lines along w their Master series (though I think that NAD's basic lines punch above their weight but a shame they look so drab.)

Glotz's picture

and I will agree that they sound dry and flat-ish. I also owned several pieces of NAD gear during that time and did not find them dry or flat.
Caveat - Compared to solid state gear now, both brands then pale in comparison to current Rotel or NAD (and the rest of the modern stereo market).

I believe it comes from lower parts quality implementation vs. Rotel's Michi gear. There a ton of spots throughout the amplification chain where cheaper parts have a cumulative effect on the sound. Michi gear addresses the parts quality throughout the circuit.

As parts-quality goes up, the immeasurables become more audible.

T.S. Gnu's picture

I would suggest that ss parts-quality goes up, the measurables become less audible. (◔‿◔)

Better parts measure better, and “disappear” by making their presence less obtrusive. And, yes, I’m being pedantic. (◔‿◔)

Archimago's picture

Hey guy, while reading the messages, I could not help but feel that often we overthink these things as obsessional audiophiles ;-). We have here a good solid-state amp that looks well made, no reason to think it would sound bad, and the measurements also provide an extra level of assurance that it was engineered quite well.

Ultimately, whether it's worth the $8000 asking price is up to the audiophile... Certainly not the most expensive thing out there.

Regarding transparency, IMO, it only makes sense to be simple with the definition as it applies to the hardware as: "the reproduction chain does not change the sound between what's on the music source and the sound waves arriving at the listener's ears".

Whether the listener enjoys the "transparent" sound is really another question altogether. Nothing wrong with having preferences for something different.

These days, most music is consumed digitally so I think it's fair to say that a "transparent" system allows us to hear the implied sound on the data stream or played on CD; warts and all. A highly transparent system will not always reproduce "unveiled" sound.

Often, the recordings themselves are "veiled", "colored", "lacking in blackness" between notes or whatever negative we can use to describe a lack in fidelity. I think that's an area reviewers need to be mindful of: there is such a thing as transparent reproduction hardware, and also transparent sounding recordings. Each can be described as having a certain level of "fidelity" when done well, best when both hardware & software sides synergize.

As for amplifiers, I think it's quite easy to demonstrate that not all amps sound the same, for example:
http://archimago.blogspot.com/2021/08/summer-musings-no-not-all-amplifiers.html

However, I believe that measurably clean amps with little distortion, adequate power, relatively flat frequency response, low noise, low output impedance (high damping), all approach a certain type of "high fidelity" sound. So a good amp like the Michi here more than likely will sound like any other high quality, high fidelity amplifier.

Anton's picture

:-)

David Harper's picture

For the record my gear is;

OPPO 203 UDP
Yammy Aventage AVR (used as a pre)
Schiit Vidar amp
maggie LRS speakers

and I never said all amps sound the same. re-read my first post carefully. and I also added "only my opinion".
and as for the wimps here who ridicule me for being 70 let me advise you that you, to, will be 70 some day.

providing that you don't ridicule the wrong 70 year old before you get there.

David Harper's picture

Normal people use their gear to listen to music.
Audiophiles use music to listen to their gear.

ARX's picture

From an electro-physical perspective, excluding the digital domain, each part - thus each of the materials used in those parts - affects a signal.
Whether we can actually measure or hear these effects in individual components, let alone a complete system, is another matter.

steve59's picture

I'm startled at the differences different amps can make on speakers, I've even owned a pair of speakers persona 7f I could, on occasion hear differences between dac's, and I've been on construction sites for 40 years subjected daily to 120+ db levels. I don't have a problem with DH saying all amps, except flawed ones sound the same, that's his experience and who am I to deny it? When somebody tells me my experience was imagined I can defend my position, consider their scientific reasoning and reevaluate or deny. If I deny then what makes me different than the complete stranger that tells me i'm wrong?

Fact is, and this is for you DH, most of us that have worked our entire careers and are finally at the point to buy a dream system are very close to your age and have accumulated similar levels of wisdom if not education, and have tested the placebo effect many times against perceived value of hi fi components along with every other significant purchase we make and are entitled to our findings as are you.
Kef Blade 1
Mc611x2
c49
project pre box s2 digital dac & roon nucleus.

X