Amps question

[Jphillips1963]

I'm in the process of adding an amp to my setup. Being confused by the different classes of amps, can someone with extensive knowledge of either owning or reviewing the different classes and brands give input of what each class amp is. The pros and cons of each.
I've recently demoed Parasound, Emotiva, NAD and one other brand I can't recall, then the final a McIntosh and I was blown away and sold by the difference in sound quality the Mac had over the others. I'm told I shouldn't have heard that kind of difference in just an amp but there was. So I'm confused and would like input on the subject.

Thanks in advance guys.

James

 

[Todd Anderson]

@Sonnie you have some experience with Parasound and Emotiva, no?

JPhillips, I run a five-channel Emotiva XPA-5 (which is a class A/B amp). It has been great (never seems to run hot). I wish I were more versed on the reasonings behind various designs... typically, Class D is said to run much cooler than A or A/B. Pioneer, I believe, is one of the few companies to use Class D amps (and have done so for roughly 5 years now?)

 

[Tony V.]

Hi James, let me work on something for you regarding the classes of amps. I will get that up here sometime tonight if I have time.

 

[Sonnie]

I've had all of those... personally could not tell you any differences I've ever heard in them... they are all very very good amps. I think I mentioned to you already that if you heard a "night and day" difference in any amp, there is likely something else going on. Subtle differences maybe, but "night and day"... something is array for sure.

The only con to any of the classes that I am aware of is Class A because it "may" require more power to operate... will "possibly" burn more electricity... and some may get a bit more warm than the other classes. The Parasound was a favorite in our amp testing we did several years back... as was the Emotiva XPA-2... and I believe it was a gen 2. The Emotiva XPA monoblocks class A + A/B that I have now do not get very warm at all.

I would say get the one you can afford that looks the best to you.

 

[ddude003]

Hello James,
It would be interesting to know which McIntosh amp you were looking at... Was it tube or solid state? Autoformers or not? Did you get a chance to hear it with your source, preamp and speakers? Were the other amps with your source, preamp and speakers?

As a McIntosh owner, inquiring minds would like to know... 8^)

PS - McIntosh and Martin Logan seem to have a synergy...

 

[Tony V.]

So we will be putting together a really good information page about this subject so I won't get too detailed but just for a quick reference:

Class A: is always drawing power and creates a fair amount of heat even when not producing sound at a speaker. They also tend to be very heavy.

Class A/B: (the most common by far) when on standby or under little load are quite efficient and will switch to a class A when demand becomes high.

Class G/H: are similar to A/B but are more efficient and the design is much more costly so usually only used in high end amps.

Class B: are usually used in Tube amp design and are usually used for amps wanted for instrument amps and some headphone amps. These tend to have a higher distortion level and give a warmer sound.

Class D: is a digital (solid state) design and is a rather new design that is efficient, lightweight and runs cooler than others above.

So what is best, well each has its pros and cons. In the end cost and what you plan on driving as a speaker load is what needs to be considered first.

 

[Jphillips1963]

Hello James,
It would be interesting to know which McIntosh amp you were looking at... Was it tube or solid state? Autoformers or not? Did you get a chance to hear it with your source, preamp and speakers? Were the other amps with your source, preamp and speakers?

As a McIntosh owner, inquiring minds would like to know... 8^)

PS - McIntosh and Martin Logan seem to have a synergy...

The McIntosh amp was the MC303. Yes I demoed apples to apples, I run a Marantz SR 6011 with Martin Logan Motion 40's for FR & FL with a Motion 30 for a center. This is how it was demoed. I brought a SPL meter so that the listening levels were the same as well.
The music was so pure and clean I couldn't believe there was that much difference. I had no intention of having them demo a McIntosh but since it was there and I asked they gladly hooked it up.

What I'm unsure of is what they used from my outputs to their inputs as my receiver doesn't have balanced outputs where the amp has balanced inputs?

 

[Jphillips1963]

I've had all of those... personally could not tell you any differences I've ever heard in them... they are all very very good amps. I think I mentioned to you already that if you heard a "night and day" difference in any amp, there is likely something else going on. Subtle differences maybe, but "night and day"... something is array for sure.

The only con to any of the classes that I am aware of is Class A because it "may" require more power to operate... will "possibly" burn more electricity... and some may get a bit more warm than the other classes. The Parasound was a favorite in our amp testing we did several years back... as was the Emotiva XPA-2... and I believe it was a gen 2. The Emotiva XPA monoblocks class A + A/B that I have now do not get very warm at all.

I would say get the one you can afford that looks the best to you.

Sonnie,

Yes you were the one whom mentioned I shouldn't had heard that much difference between the amps I demoed. I don't know how to explain what I heard, it the music was so much cleaner and the highs were really crisp. That's why I'm so confused as to why or how there was this much difference in what all I listened to. I had my mind set on the Parasound when I went in for the demo. My budget was going to be at the 3000-3500 range but unless something comes along that bests that Mac guess I'm going to need to double that budget.

BTW thanks for the great sub, I'm still a bit blown away by the size. And here I was already considering a second to make a pair, but that's before I saw the size and of this PB16.

 

[Todd Anderson]

Hearing some kind of difference isn't outside of the the realm of possibility... I would be curious to know if all other factors were kept constant?

 

[Jphillips1963]

Hearing some kind of difference isn't outside of the the realm of possibility... I would be curious to know if all other factors were kept constant?

I would agree, but they had no clue I wanted to hear a McIntosh amp since it fell outside my price range. The other amp I demoed was the Rotel. When I asked to hear the Mac they pulled the Rotel out and hooked up the Mac.
I dug thru my notes and listed in order what sounded best prior to listening to the Mac are as follow. Rotel, Parasound (these two were neck and neck) then the Emotiva and last the NAD.
Then I asked about the Macintosh and that moved to the top with no doubt.
So it's beyond me why or how it just sounded so much better.

 

[Todd Anderson]

Same speakers, same room, and same preamp used in the demo?

 

[Peter Loeser]

Difference in power ratings between the amps? I have owned all on your list (except Emotiva) and more. While I absolutely love the look and performance of McIntosh my experience has been that the night and day sound quality improvements come from speaker selection/positioning and room acoustics rather than amp selection (assuming amp power ratings are appropriately matched to speakers).

The differences in amp class could theoretically be measured at the output but aren't likely to be detectable by the average ear. As with anything else, there is a balance of cost, practicality, and performance. When selecting an amp I tend to lean toward the one best suited for my budget and application, since most modern amplifiers deliver very good sound quality. I sincerely don't think you would be disappointed by anything from the likes of Parasound, Emotiva, NAD, Rotel, etc in a well set up room. However, if you have the budget and you can't resist the McIntosh blue VU meters, I am compelled to support your decision to buy one

 

[Jphillips1963]

Same speakers, same room, and same preamp used in the demo?

Yes we were in the same room and were using everything exactly the same. I even checked and asked. As I thought they may were trying to pull one over on me. I went as far as walked up to the speakers to be sure they were playing and not some other speaker, I also turned the volume up and down on the AVR, actually I adjusted the volume for every amp to equal out the sound to the meter.

 

[Todd Anderson]

not to ask the obvious, but was your location in the room the same?

Just out of curiosity, what kind of speakers were demoed?

 

[ddude003]

So, the McIntosh MC303 is a 3 channel, 300 watt rms per channel solid state amp with autoformers... Balanced and unbalanced inputs... The guys at McIntosh seem to rate the output on their amps conservatively... My guess is that this amp is more on the order of 400 watts per channel...

I know many will disagree, OEM specs are just that, specs... Every design is in one way or another different... And different designs with different parts makes different sounds...

There is something to be said about hurling 900 to 1200 watts of electrons thru 125+ lbs of copper (read autoformers) into the blue charged atmosphere of your listening space... 8^)

Enjoy the differences...

 

[Sonnie]

Another thing to remember is simply changing the volume a few db can make one amp sound different than another... or should I say make a more drastic difference in the sound as you might have experienced. Otherwise, the only way you'd hear a "night and day" difference is if something was drastically different in the setup. The idea behind an amp is not to change the sound you hear... it's to keep it neutral and not color the sound, therefore drastic "night and day" differences would not be a good thing in an amp, as it is doing something unnatural.

 

[ddude003]

If all amps sounded the same there would be no market for the number of OEMs amps available. If you really what to see the differences in your amps then throw them up on a bench, get out your signal generator and oscilloscope... You will see differences... Every OEM has a different way that they test and derive their specs... There is no UL of amp specs... Yet...

Oh... One persons distortion/noise may be anothers warmth... Even I own a second order harmonic generator (read tube amp)... 8^)

“In theory, there is no difference between practice and theory. In practice, there is.” - Yogi Berra

 

[Jphillips1963]

not to ask the obvious, but was your location in the room the same?

Just out of curiosity, what kind of speakers were demoed?

Yes I was taking measurements right at the AVR so I could tweak the volume to get the same decibels on the meter. Then I'd go sit down and listen the same sound tracks over and over for 5-10 mins on estimate.
Speakers demoed were Martin Logan Motion 40's for the LF & RF speakers and the Motion 30 center channel. That's the exact same speaker I have in my home. The AVR used was a Marantz SR6011 which is also the same unit I have.

 

[Jphillips1963]

So, the McIntosh MC303 is a 3 channel, 300 watt rms per channel solid state amp with autoformers... Balanced and unbalanced inputs... The guys at McIntosh seem to rate the output on their amps conservatively... My guess is that this amp is more on the order of 400 watts per channel...

I know many will disagree, OEM specs are just that, specs... Every design is in one way or another different... And different designs with different parts makes different sounds...

There is something to be said about hurling 900 to 1200 watts of electrons thru 125+ lbs of copper (read autoformers) into the blue charged atmosphere of your listening space... 8^)

Enjoy the differences...

I remember when we had swapped out to the McIntosh amp that the volume control was turned a lot further down to get the same decibels on the meter as the other amps. That amp has the energy for sure.

 

[Sonnie]

If all amps sounded the same there would be no market for the number of OEMs amps available. If you really what to see the differences in your amps then throw them up on a bench, get out your signal generator and oscilloscope... You will see differences... Every OEM has a different way that they test and derive their specs... There is no UL of amp specs... Yet...

Oh... One persons distortion/noise may be anothers warmth... Even I own a second order harmonic generator (read tube amp)... 8^)

“In theory, there is no difference between practice and theory. In practice, there is.” - Yogi Berra

I don't think anyone has stated that "all amps sounded the same" ... but that would not change the market if they did... people even pay more for the same identical speaker because they don't realize it can be purchased for less elsewhere... same with a car... etc., etc. It's the "night and day" differences that are going to always be questioned... even all the reviewers that have reviewed fifty-eleven amps would question "night and day" differences with all else being equal other than the amps in question... assuming one is not solid state and one tube... those might very well have a more noticeable difference.

 

[Todd Anderson]

Yes I was taking measurements right at the AVR so I could tweak the volume to get the same decibels on the meter. Then I'd go sit down and listen the same sound tracks over and over for 5-10 mins on estimate.
Speakers demoed were Martin Logan Motion 40's for the LF & RF speakers and the Motion 30 center channel. That's the exact same speaker I have in my home. The AVR used was a Marantz SR6011 which is also the same unit I have.

I'd be curious if they could arrange for a quick A-B test (quickly switching between Amps)?

Look... I don't think anything is outside of the realm of possibility (in terms of you perceiving a difference).

 

[JBrax]

I've never personally demoed different amps but I'd like to. I do fall into the camp of questioning "night and day difference" though. Like others have said you shouldn't hear a night and day difference unless variables have changed in the supply chain. Could you have been mentally swayed knowing it was a McIntosh before the demo began? My opinion is if you can afford it and you really do think it sounds worth the difference in price then why not? The blind A/B testing might be in order before pulling the trigger though.

 

[ddude003]

I don't recall the OP saying anything about a "Day and Night" difference... I don't recall that I ever said that anyone else said "all amps sounded the same"...

I will say that if I were to listen to several of those other brands 3 channel power amps and being about as careful to compare apples to apples in the listening environment as the OP did (I think he did a great job there) that I would come to the same conclusion... That is... Wow, that McIntosh sounds a lot better to me... And, in fact, I have gone thru a similar experience a few years ago in picking a 2 channel solid state power amp... And yes, I picked a McIntosh...

Maybe the real question is more about the amps themselves... Their architectures and designs, their parts and manufacturing processes and their sound...

The OP appears to have asked the basic question about classes of amps and why did the McIntosh sound better... I would submit that its the extra 100+ lbs of copper (read autoformers)... The MC303 Weighs 155 lbs all the others are less than 50 lbs...

Cordially...

 

[GFOviedo]

I'm still trying to figure out why do people say an amplifier has sound. I disconnected my speakers from the amplifier, and I started to play music from my HTCP to my AVR-X4300 to the LPA-1 amplifier, and I didn't hear any sound from it!

Now if I connect my Change A5rx-c there is sound. If I then proceed to connect my Pioneer BS22 bookshelves speaker there is sound coming out of it as well. Both brands of speakers sound different.

 

[Sonnie]

For clarification...

I don't recall the OP saying anything about a "Day and Night" difference... I don't recall that I ever said that anyone else said "all amps sounded the same"...

He said it to me when we spoke on the phone, which is why I quoted him... and why I eluded to the fact we had talked previously.

If all amps sounded the same there would be no market for the number of OEMs amps available.

Not sure what else to read into this statement but that you are assuming someone said it, thunk it or assumed it.

I certainly apologize if you meant something totally different and I interpreted it the wrong way.

I have heard numerous McIntosh amps and owned quite a few... more because I like the way they look, not because they sounded any better. I have heard the MC303 at Rocky Mountain Audiofest and at Axpona... on the same MartinLogan speakers that I have owned and some supposedly better, yet they did not sound near as good as my Parasound, my Denon AVR, my Emotiva monoblocks, my Behringer EP2500 amps, or anything else I've had in my room. It had absolutely zero to do with the McIntosh amp though. I suspect it was everything to do with setup of the speakers and perhaps lack of frequency balancing the speakers in the room they were setup in.

As far as what the OP heard... dunno... but my personal opinion is that if I were "blown away and sold by the difference in sound quality" of an amp, I would want to set it up in my home to compare it so that I could hear what remarkable improvement has happened with the development of amps of recent. That in no way diminishes the ears of those who state they can hear differences in amps... I praise those folks... Dennis Young (tesseract - who will be at my home in a few weeks reviewing speakers with us), will attest to the fact I believe he can hear differences in amps, yet he would also attest that the differences he hears are not differences that cause him to be "blown away" or would they be considered "night and day".

On another note... McIntosh adamantly refused to participate in our amp comparison event, where we had the Parasound, Mark Levinson, Krell, Pass Labs, Emotiva, Van Alstine, Sunfire, and a few ohters I can't remember at the moment. That doesn't prove anything... it's just an interesting fact to me.

James, the OP... per his post, I believe is curious if perhaps the class of amp can be making the differences he heard. I think it is the same class as the others he listened to, so what he heard would not be attributed to the class of amp.

For the record... I would LOVE to own that McIntosh amp... it is a beautiful piece of gear and no doubt it sounds as good as any other amp I have ever owned. Unfortunately it is sorely over-priced for me... even at the industry accommodation pricing that McIntosh has offered me in the past.