Marchaudio P501 Mono Block Power Amplifier Review

[xaxxon]

How does the same person own a Benchmark AND a Carver?
(That seems like it would be a difficult combo of amps to own, and a rarity to find in the same abode.)




Is OSHA no longer a thing in the US?

carver actually sounds pretty nice to me. but the lack of ability to push the advertised power kinda doomed it.

 

[antcollinet]

Nonsense.

OK, are you up for some abx testing with sine waves? let's see what distortion you can hear. we can even try some of the levels you have defined max power at in recent tests, 0.001%, 0.085% etc.

I think it is time you let it go. Surely you get the point you are not going to get a different answer.

If you feel so strongly set up a different site and do your own tests.

 

[Elmar.F]

I usually agree,but depends.
I'm listening to this right now (the blue highlighted one):




View attachment 247599

If you try to put an average at 70db you will surely grab the remote to lower it at some points.
And it's a single piano.

A bit off topic but I'd much appreciate a response. Assuming you have a speaker like the one tested here and you listen mostly to highly dynamic music like you mentioned above how much power is needed to drive these speakers without audible or with an acceptable amount of distortion? (Listening distance 2.5m)

 

[Sokel]

A bit off topic but I'd much appreciate a response. Assuming you have a speaker like the one tested here and you listen mostly to highly dynamic music like you mentioned above how much power is needed to drive these speakers without audible or with an acceptable amount of distortion? (Listening distance 2.5m)

According to the measurements it seems that it cannot handle much power.If I had these I would use them in a small room at 1.5 meters triangle with a nice 2X100 watt@4ohms amp.Generally for high dynamic music at 2.5m I would choose something else.

 

[Sokel]

What is odd is that a company like Ice Power,otherwise considered honest,describes that 1% as "unclipped" when there are sure signs of clipping.
Another interesting point is where to put the knee point.At 100Hz?At 1Kkhz?At 6.66Khz (which is the worst case scenario with H2 and H3 well into 20Hz-20Khz)?
As it seems it's hard to put a standard and Amir's point seems fair.

 

[Holmz]

carver actually sounds pretty nice to me. but the lack of ability to push the advertised power kinda doomed it.

Does the Carver also not play loud enough?
Or does it seem like it does?

The fact you like, sorts of makes me question how important low distortion is.
Usually the high distortion amps or speakers tend to sound a bot louder, and low distortion seem a bit quieter, from what I have observed.

The distortion profile is also somewhat glossed over in favour of SINAD… and in the case of these amps, 400W (or whatever it is), is a lot of watts, and should be about 20W RMS, which is generally going to [put us in the 100dB(A) range.
That seems like a far blast of sound.

 

[JasonWells]

Once more... it doesn't matter to me what Thin Blue does. What he shouldn't do is measure power on the sweep with the cursor at the last clipping point, and compare it to my measurement of an amp where I put the clipping point at the knee.

The amp he measures has THD of 1% at his cursor, whereas mine is at 0.001% or 100 times less. Clearly I could have moved the cursor to the right and put it at the top of graph to show "more power." But as I have repeatedly explained, that is not proper.

As to "examining" my methods, all I am reading is that you don't understand them or my explanation of the same. You keep demanding to know power at one distortion level. I showed you that in a different measurement. The sweep method above CAN NOT show you that. It is by accident that OP's measurement landed on 1%. It could end any where it wants.

There is no such thing as the last clipping point. you are inventing terms. it's simply the power at 1% thd+n.
He didn't compare this value to your interpretation of max power, he simply stated readers should compare the data and graphs.

So what's proper about choosing random points somewhere around the knee? why should it be 0.001%, 0.01% or any of the other values you choose on that particular day?

So if the sweep measurement is so useless why are you using it to define max power?

 

[JasonWells]

No it isn't because you can't say one test with a fixed peak resembles all music and content. It is another value so I post it, mostly to show if there is headroom.

Headroom to 1% which you say is an unacceptable level of distortion. not sure I understand your reasoning in that case.
Anyway you completely missed the point. I never said it resembles all music. I said that in terms of power output a continuous sine bears no resemblance to music. you will never get any where near that continuous level with music. the peaks are much higher so the burst output of an amp is a more relevant metric to real world performance.

 

[JasonWells]

Given this, I assume you agree that no one should be in the market to buy March Audio amp. Find a much cheaper, high distortion one instead. Tons of commercial class D amps do that job for much less money. I am thinking Crown, Behringer, etc. Agree?

How do you draw that conclusion? I have been very clear this isn't about any specific distortion level. it's about your reasoning for the numbers you are producing and expecting thin blue to follow suit.
Where does thin blue take the measurement on the knee?

 

[JasonWells]

You made the claim of inaudibility, I did not. So you need to provide proof. For my part, I can do one better with published ABX test with real music:

Double Blind tests *did* show amplifiers to sound different

In many online debates, position taken by some that when amplifiers are used that have flat frequency response and low distortion that no double blind tests have shown them to sound different. Well, I managed to dig up a 32 year old test that says otherwise. What is fascinating is that one of...

www.audiosciencereview.com

This small incursion into clipping region caused this result:

This is why you want to avoid going beyond the knee of the distortion sweep test.

Your study is missing crucial information. what was the distortion levels when "clipping". what was the severity of the clipping? eyeballing a scope is not an accurate measurement.
You are implying clipping is a hard line. it isn't.
Are you saying that an amp is clipping and thd is audible at 0.001%? would you like to take part in an abx test and identify the track with 0.001% thd? Let's arrange it.

 

[restorer-john]

@JasonWells

Alan, just give it up. You're so predictable, it's hilarious.

You look like a complete and utter clown. Again. You trash your own brand, get banned, rinse and repeat on every site. Over and over.

 

[JasonWells]

What is odd is that a company like Ice Power,otherwise considered honest,describes that 1% as "unclipped" when there are sure signs of clipping.
Another interesting point is where to put the knee point.At 100Hz?At 1Kkhz?At 6.66Khz (which is the worst case scenario with H2 and H3 well into 20Hz-20Khz)?
As it seems it's hard to put a standard and Amir's point seems fair.


View attachment 247703


View attachment 247704

Clipping isnt a hard line. wave forms distort prior to the tops being literally chopped off.

 

[restorer-john]

Clipping isnt a hard line. wave forms distort prior to the tops being literally chopped off.

No, they do not. And that is what shows you really have zero idea of how amplifiers actually clip. I suggest you buy yourself a distortion analyser, hook up your 'scope and actually look at how a variety* of amplifiers clip.

*not just your Hypex/Purifi babies.

 

[JasonWells]

@JasonWells

Alan, just give it up. You're so predictable, it's hilarious.

You look like a complete and utter clown. Again. You trash your own brand, get banned, rinse and repeat on every site. Over and over.

@restorer-john I assume you are referring to Alan March of March Audio. that's not me.

 

[JasonWells]

No, they do not. And that is what shows you really have zero idea of how amplifiers actually clip.

Please enlighten me. are you saying that no distortion happens until the power rail voltage is met by the signal and the waveformxgets truncated?
So you think an amp is clipping audibly so at 0.001% thd?

 

[Sokel]

Clipping isnt a hard line. wave forms distort prior to the tops being literally chopped off.

Distortion is one thing,clipping is another.
That's why I said that is odd that Ice Power says that this 2200-2000 watts up there are unclipped.
Even if the chart is not analogous and the line would be a lot less steeper if stretched we can clearly see the kick.

 

[restorer-john]

Please enlighten me. are you saying that no distortion happens until the power rail voltage is met by the signal and the waveformxgets truncated?
So you think an amp is clipping audibly so at 0.001% thd?

or is it this post prior, Alan?

Classic March edit the post after someone else has replied. Yawn.

When will you learn?

 

[JasonWells]

I

Distortion is one thing,clipping is another.
That's why I said that is odd that Ice Power says that this 2200-2000 watts up there are unclipped.
Even if the chart is not analogous and the line would be a lot less steeper if stretched we can clearly see the kick.

I agree. there appears to be some conflation of the two going on. you can't compare the chart to the readings from the burst test. the burst is for very short durations so in all probability the power supply voltage will not sag. longer durations or continuous the psu voltage will drop hence more distortion or even clipping.

 

[JasonWells]

or is it this post prior, Alan?

View attachment 247763

Classic March edit the post after someone else has replied. Yawn.

When will you learn?

I have reported you and put you on ignore.

 

[Sokel]

I

I agree. there appears to be some conflation of the two.

Yep.

That's distortion:

And that's what clipping looks like.
Ugly thing: