Amp question.

[amey01]

Amey. Who cares? I guess the question is given the original responses why would he be replacing his current setup since all amps sound the same? Given that - do I care what the impressions are? Nope.

Yes, I know. Very true. One must ask also though - why is he replacing with an NAD when he could get a Sony or a Pioneer for a fraction of the cost.........all amps sound the same and all.......

 

[timm]

I have an onkyo 818. Why is it that when I added an Emotiva XPA 3 I hear no difference in sound quality? I have Electromotion ESL's.

Here are my thoughts on this.... I have heard many amps - I have directly A/B'd them as well. Differences are heard at low listening levels... and I think those differences are really about system synergy...what you can hear...sonic signature of the amp... Here are my opinions on several amps:

Sunfire: warm/smooth/big
Bryston: detailed/layered/powerful
Mac solid state: warm/bit more detail
Prima Luna: round/warm/bass defintely sounds different because of the tubes.
Rotel: seemed kind of flat to me - compared directly to Sunfire
Most AVRs that I have heard: a bit thin/not quite as full as any of the above (not to say there aren't good ones ...I just haven't heard them)
ARC solid state: seems very neutral to me...very layered soundstage.

This might vary from model to model -- but I am betting that we could all (or most of us making other points statistically irrelevant) probably come to some type of close analogy among us if in fact you have heard the models etc...

Personally, with my experience (I am not claiming a lot here...) .. I have yet to hear a jaw dropping...OMG...difference with an amp. Differences yes... presentation - yes... more preference than good vs bad if you will... But, I am suspecting that there are amps that would do that for me... I either just haven't heard them or don't have the wallet. The system synergy is going to determine what sounds the best for a particular amp. Some systems may need more detail... others may need warmth....some folks shoot for total neutrality...some speakers are so difficult to drive the amp could also become unstable...so another amp might be more suitable.

I never heard real differences in Pre-amps... but here was my experience:
Carver Pre to Sunfire Pre ... to me really sounded very close... I am not sure if I could have told the difference if I was blind folded...
Carver/Sunfire/Yamaha AVR used as a pre: again to me not anything that I am sure I could have told you ... hey that one is WAY worth it...
Then I got a Cary Slp98p pre-amp and my jaw literally hit the floor!!! The difference was staggering...soundstage deep and wide ...texture...blahblahblah...

So, my point is - just because you haven't heard differences -- don't jump to the conclusion that there ARE no differences in amps/pre-amps. People are not telling lies to justify their expenditures. As you see in my examples above - I had several amps and several pre-amps sound similar...others sounding different. I had not heard a different sounding pre-amp - up until several years ago... But, I did find it after 20+ years... and only then did I know what people were talking about when they were discussing the importance of the pre-amp in the chain. Amps are truly the same.

As far as your experience with Emotiva and your AVR -- again, maybe from a sonic signature standpoint - the two are close... I am pretty sure you bought it without hearing it since they are online? I wouldn't expect a huge difference between an onkyo and the xpa-3...haven't heard them - but the xpa series is their cheaper amp isn't it? I would expect a slight difference...and probably a difference you might discern if you a/b'd things as roberto was suggesting.... Worth the money? Only for you to decide that...

 

[Gordon Gray]

Hi timm,

Good observations. I have two separate systems, two channel and HT. Regarding AVR's for HT, I've always liked Denon. Not the last word (at least the models that I've owned) in many areas, but the midrange is quite satisfying, ample power, no fatigue, good adjustability options, and very good reliability. What else can you expect for $800?

Gordon

 

[timm]

Hi timm,

Good observations. I have two separate systems, two channel and HT. Regarding AVR's for HT, I've always liked Denon. Not the last word (at least the models that I've owned) in many areas, but the midrange is quite satisfying, ample power, no fatigue, good adjustability options, and very good reliability. What else can you expect for $800?

Gordon

I agree Gordon .. I like the Denon AVRs as well actually... I have had a lot of good experience with denon and reliability.... and when I say reliability ... I mean no problems for 30 years type of reliability....a cd player that still operates flawlessly... now is my old cd player with the analog outs (only) the last word on resolution?:.... no... but, I still like it.... and I have denon 5900 universal.... never had any issue with it.. for 9 years I think? My yamaha avr is completely flat and bland sounding compared to my sunfire / cary combo... no comparison whatsoever...

 

[Gordon Gray]

timm,

Sounds like you might want to sell your yammy.

Regarding preamps, I've been wanting to replace my CJ Premier 18LS preamp, mainly due to new technology, with the CJ ET5. The 18 still works flawlessly but I'm confident that the ET5 will be a major upgrade.

Only down side is the dreaded break in. Reported by many to be a minimum 300 to 500 hours due to the capacitors. UHG!

Gordon

 

[Rich]

Only down side is the dreaded break in. Reported by many to be a minimum 300 to 500 hours due to the capacitors. UHG!

That's not so bad, Gordon. You just have to leave it playing 24/7 for three weeks, and then you are good to go.

 

[Pneumonic]

Amplifier measurement is a very complex matter. There are a couple of quite interesting papers on Nelson Pass' homepage. The problem is that most measurements are done with a single (or at most two) tones present at the same time. But this does not properly account for the way various distortion phenomena are perceived by our ear/brain interaction.

Whereas I agree that many people underestimate the power that is required to avoid clipping, this alone does not explain why amplifiers sound so different at low levels. And "lumping" everything into a single distortion parameter does not tell much either. We all know that 2nd and 3rd order distortion is much more difficult to hear than higher order distortion at the same level.

Even Stereophile's measurements does not tell the whole story. They limit themselves to two-tone intermodulation effects. And already there it becomes very difficult to interpret the measurements.

Many of us find many tube amplifiers to sound less harsh at low level than many SS amps. This is often attributed to high-frequency roll-off. But why? There are several tube amps that measure flat to above 50 KHz, so surely high frequency roll-off can not be the reason.

There is one thing I find a bit strange: When an amp sounds clinical, we tend to name it neutral or uncolored. When an amp sounds warm, we tend to name it colored. Could it not be the other way around? That the clinical sound of some SS amps actually is a coloring from various distortion effects? And that the warm sound from a well-designed tube amp below clipping actually is from the lack of this distortion?

As long as we are measuring amplifiers with single or two-tone test signals, I doubt that we will be able to relate all sonic differences to measurements.

I can’t speak well enough on how the brain/ear perceives audio things (which is why I posted what I did in post #55 in this thread) but, technically, an amp never deals with multiple tones. Music consists of thousands of frequency tones which all combine together to form 1 single voltage at a given period of time. As a result, no matter how complex the music and no matter how many frequencies are involved, the voltage at any given time will be a single value. It doesn’t matter if it’s asked to reproduce 1, or 2 or 1,000 or 1 million tones; the audio signal the amp deals with will only ever consist of 1 voltage at any given time. So, tying this into IMD (which I think is your point) ...... an amps nature to produce IMD will be the same regardless of how many frequencies are present (as long as there is more than 1 frequency present to cause modulation).

If there is just 1 test tone, then we measure total harmonic distortion. Practically speaking though, in all well designed amps, THD and IMD are essentially the same. That’s why engineers rarely bother to measure IMD as it can be easily deduced from the THD measurement.

Also note that in well designed amps, any simple/complex distortion patterns are mitigated to inaudible levels. Exceptions to this might be an amp which doesn’t employ any feedback; these amp designs very well could have audible levels of distortion and, therefore, might easily sound different from one another. If an amp is designed to produce audible levels of distortion then one could argue its design is questionable though, perhaps, not undesirable by some because they may enjoy the sound of said distortion. Thus we enter into the subjectivists versus objectivists argument.

 

[Bevensee]

I can’t speak well enough on how the brain/ear perceives audio things (which is why I posted what I did in post #55 in this thread) but, technically, an amp never deals with multiple tones. Music consists of thousands of frequency tones which all combine together to form 1 single voltage at a given period of time. As a result, no matter how complex the music and no matter how many frequencies are involved, the voltage at any given time will be a single value. It doesn’t matter if it’s asked to reproduce 1, or 2 or 1,000 or 1 million tones; the audio signal the amp deals with will only ever consist of 1 voltage at any given time. So, tying this into IMD (which I think is your point) ...... an amps nature to produce IMD will be the same regardless of how many frequencies are present (as long as there is more than 1 frequency present to cause modulation).

If there is just 1 test tone, then we measure total harmonic distortion. Practically speaking though, in all well designed amps, THD and IMD are essentially the same. That’s why engineers rarely bother to measure IMD as it can be easily deduced from the THD measurement.

Also note that in well designed amps, any simple/complex distortion patterns are mitigated to inaudible levels. Exceptions to this might be an amp which doesn’t employ any feedback; these amp designs very well could have audible levels of distortion and, therefore, might easily sound different from one another. If an amp is designed to produce audible levels of distortion then one could argue its design is questionable though, perhaps, not undesirable by some because they may enjoy the sound of said distortion. Thus we enter into the subjectivists versus objectivists argument.

Sorry, but: Complete and utterly nonsense! The music signal is not DC. It is a timevarying signal comprised of many different tones. If what you claim was true, our amps could not play, say, a chord, let alone music.

Lumping IMD and TDH into one single value is misleadong. Imagine two amps, both having 2% THD. One of them has only 2nd oreder, the other only 7th order. In your world they sound the same. Even worse: be extension of your logic, all instruments sound the same if they play the same note and has the same total amount of overtones. If you can't hear the difference between amps, fine. But don't tell the rest of us that we can't either. Thank you very much.

 

[Pneumonic]

IMD is an innate characteristic of amplifiers and has nothing to do with the audio signal, which remains a single voltage at any point in time.

Understand that when reproducing music, the frequency of the voltage will vary over time as will the amplitude of the voltage. No matter what, the amplifier will only have to reproduce a single voltage (which will vary in how quickly it changes) at any point in time.

BTW, I'm not attempting to tell people that they can't hear what they hear. I'm attempting to explain why, technically, the OP couldn't hear any difference when changing his amps.

 

[Bevensee]

Single voltage in time. Not single frequency. Try to fourier transform a time domain audio signal. This will give you the spectrum, and show you that many tones are present at the same time. Try to read this paper from Nelson Pass: https://passlabs.com/articles/audio-distortion-and-feedback

 

[JordanD]

Fourier Transforms FTW!

 

[Pneumonic]

Single voltage in time. Not single frequency. Try to fourier transform a time domain audio signal. This will give you the spectrum, and show you that many tones are present at the same time. Try to read this paper from Nelson Pass: https://passlabs.com/articles/audio-distortion-and-feedback

Hello, check your PM please.