HydrogenAudio

CD-R and Audio Hardware => Audio Hardware => Topic started by: John 31415926 on 2016-10-21 07:32:22

Title: How do "objective" audiophiles choose an amp?
Post by: John 31415926 on 2016-10-21 07:32:22
I just read my first ever article by an objective audiophile discussing the idea that all amps, within comparable parameters, do the same thing and sound the same, regardless of price.  I had never heard that before.  I had always bought into the idea that one amp surely sounded better than another.  It's still a little hard to get my head around the idea that a $4,500 Mcintosh amp has the same effect on an audio signal as a $400 Onkyo ... but that is the argument that these so-called objective articles and blind tests make. 

It's even harder when product review after product review compares the amp being discussed to other amps and the writer argues this one is "crisper" and that one is "warmer" and so on.

So if that's true ... that all amps have the same effect on an audio stream ... how do we choose an amp?  I know a guy would want to spend a few bucks to make sure the components are of rugged enough quality so the thing actually lasts a few years.  That costs money.  A guy would also want to make sure it has the features he wants.  More features would cost more money.  Same with wattage. 

Beyond that, how does someone who buys into this "all amps do the same thing" belief choose an amp?  And what's the right amount to spend before steep diminishing returns kick in?  $200?  $500?  $1500?  I intended to spend up to $2,000 on an amp while I was still caught up in the marketing, but now I really have no idea at what point money is wasted on buying a "better" amp.
Title: Re: How do "objective" audiophiles choose an amp?
Post by: mudlord on 2016-10-21 08:09:48
Double blind tests.

It's still a little hard to get my head around the idea that a $4,500 Mcintosh amp has the same effect on an audio signal as a $400 Onkyo ... but that is the argument that these so-called objective articles and blind tests make. 

Yeah, it can be shocking at first to have notions shook by scientific tests. It was the same for me when the first time I did something audio related, like comparing different compression rates of codecs to suit my limits of hearing.

Quote
It's even harder when product review after product review compares the amp being discussed to other amps and the writer argues this one is "crisper" and that one is "warmer" and so on.

Emotional things like "warmer" should be taken out of the equation for me at all. Since those seem like complete buzzwords to me. Just what does "warmer" mean?
Title: Re: How do "objective" audiophiles choose an amp?
Post by: KozmoNaut on 2016-10-21 08:45:19
There can be differences in sound between amps, or more precisely in their interactions with the speakers. For instance the difference between an amp with a normal damping factor, and one with really low damping factor. The amp with the low damping factor will have less of a braking effect on speaker cone movement, which can lead to "woolly" or uncontrolled bass response, especially in speakers that use large woofers.

But this hasn't really been an issue for a long time, at least for solid state amps, and there is no definite correlation with price.
Title: Re: How do "objective" audiophiles choose an amp?
Post by: antz on 2016-10-21 09:22:42
I just read my first ever article by an objective audiophile discussing the idea that all amps, within comparable parameters, do the same thing and sound the same, regardless of price.  I had never heard that before.  I had always bought into the idea that one amp surely sounded better than another.  It's still a little hard to get my head around the idea that a $4,500 Mcintosh amp has the same effect on an audio signal as a $400 Onkyo ... but that is the argument that these so-called objective articles and blind tests make. 

It's even harder when product review after product review compares the amp being discussed to other amps and the writer argues this one is "crisper" and that one is "warmer" and so on.

So if that's true ... that all amps have the same effect on an audio stream ... how do we choose an amp?  I know a guy would want to spend a few bucks to make sure the components are of rugged enough quality so the thing actually lasts a few years.  That costs money.  A guy would also want to make sure it has the features he wants.  More features would cost more money.  Same with wattage. 

Beyond that, how does someone who buys into this "all amps do the same thing" belief choose an amp?  And what's the right amount to spend before steep diminishing returns kick in?  $200?  $500?  $1500?  I intended to spend up to $2,000 on an amp while I was still caught up in the marketing, but now I really have no idea at what point money is wasted on buying a "better" amp.
The last paragraph above is phrased rather as though you dispute that "all amps sound the same". It's not really a belief that is "bought into", more a case of plain science. At all realistic power levels, solid state modern amps of competent design have distortion levels that are beyond the ability of the human ear to distinguish. Additionally, any distortion they do produce will be masked by the (proportionally) far greater distortion introduced by even the best of speaker systems. Amplification of audio today is a solved problem. Clearly, this is a blanket statement and it's quite possible to find amps that are not "of competent design" and behave badly with certain loads or are non-linear in some way.

The best advice is simply to stick to a reputable manufacturer, determine what wattage is required then add the desired features. You will then arrive at a suitable amplifier. It's quite possible that you could have bought the same performance in a cheaper, not well-known, brand but at least you should get security of warranty etc. and you won't have been ripped off. Frankly I'd steer clear of unsubstantiated reviews containing buzzwords, in the hi-fi press.
Title: Re: How do "objective" audiophiles choose an amp?
Post by: Northpack on 2016-10-21 09:51:40
By choosing an inexpensive digital ("CLASS D") amplifier providing sufficient power output for the speaker system. Benefit: lower noise floor (probably the only characteristic of a modern amplifier that can be clearly audible) and significantly reduced power consumption:

(https://upload.wikimedia.org/wikipedia/commons/a/a0/LeistungsaufnahmeABD.png)
(Power consumption as a function of output power)
Title: Re: How do "objective" audiophiles choose an amp?
Post by: Arnold B. Krueger on 2016-10-21 13:15:32
I just read my first ever article by an objective audiophile discussing the idea that all amps, within comparable parameters, do the same thing and sound the same, regardless of price.  I had never heard that before.

This is actually a pretty old idea, easily going back to 1977 or earlier:

First ABX power amp test - 1977 (http://djcarlst.provide.net/abx.htm)

"May 7, 1977 SMWTMS did the first ever audio double blind subjective listening tests. An argument over the audibility of differences between amplifiers at a club meeting in November 1976 resulted in an agreement that a double blind test could settle the question. Just six months later, Arny Krueger gave a lecture on his design of a double blind comparator and the first three double blind tests were done. The results include the first three listed in the Power Amplifier Comparison Table in the data. Thus we credit Arny Krueger and his opponent in the argument, Bern Muller, as the inventors of the ABX Comparator. ."

Quote
I had always bought into the idea that one amp surely sounded better than another.

Is that a rational thought? If all amps sound better than each other, how can any of them sound better?

Quote
It's still a little hard to get my head around the idea that a $4,500 Mcintosh amp has the same effect on an audio signal as a $400 Onkyo ... but that is the argument that these so-called objective articles and blind tests make. 

The actual argument (and relevant facts) can go like this:

The human ear, like every other part of the human body has performance limits. Some differences are just to small for people's ears to hear. Eventually, after more than a half century of development, the amps became so well perfected that their differences became to small to hear.

Quote
It's even harder when product review after product review compares the amp being discussed to other amps and the writer argues this one is "crisper" and that one is "warmer" and so on.

Are you shocked that salesmen at least occasionally umm... embroider the truth? ;-)

Quote
So if that's true ... that all amps have the same effect on an audio stream

That's not true. Some amplifiers are audibly inaccurat., Sometimes they are made that way completely intentionally.  Others are not. Therefore not all amps sound the same.

Quote
... how do we choose an amp?

An ideal amplifier would have no audible imperfections, no?  We can compare amplifiers to other things that have no audible imperfections. If the amp sounds the same as something that is audibly perfect, then the amp might be a good choice if well made, reliable, flexible, and reasonably priced, no?

Fortunately as time has marched on, more and more audio amps have been perfected to the point where they meet this standard.

Quote
I know a guy would want to spend a few bucks to make sure the components are of rugged enough quality so the thing actually lasts a few years.  That costs money.

Not true. I have some inexpensive audio gear that is like 50 years old and still meets its origiinal specifications, and more importantly has no audible flaws.

Quote
A guy would also want to make sure it has the features he wants.  More features would cost more money.  Same with wattage. 

High performing, well built, well featured gear is not hyper-expensive.

Quote
Beyond that, how does someone who buys into this "all amps do the same thing" belief choose an amp?  And what's the right amount to spend before steep diminishing returns kick in?  $200?  $500?  $1500?

Depends on things like features and power capabilities.  There are sub-$100 amps that are sonically ideal, well made, and last for a long time.

Quote
I intended to spend up to $2,000 on an amp while I was still caught up in the marketing, but now I really have no idea at what point money is wasted on buying a "better" amp.

Probably, a point you have already passed.
Title: Re: How do "objective" audiophiles choose an amp?
Post by: ajinfla on 2016-10-21 18:21:37
the idea that all amps, within comparable parameters, do the same thing and sound the same, regardless of price. 

So if that's true ... that all amps have the same effect on an audio stream ...
This is Dunning-kruger effect, as seen ad infinitum.
Title: Re: How do "objective" audiophiles choose an amp?
Post by: greynol on 2016-10-21 19:03:37
https://hydrogenaud.io/index.php/topic,104049.msg854076.html
https://hydrogenaud.io/index.php/topic,106640.msg872165.html
https://hydrogenaud.io/index.php/topic,107277.msg878192.html
https://hydrogenaud.io/index.php/topic,107944.msg885897.html
https://hydrogenaud.io/index.php/topic,108285.msg889306.html
https://hydrogenaud.io/index.php/topic,108640.msg892594.html
https://hydrogenaud.io/index.php/topic,108596.msg892186.html
https://hydrogenaud.io/index.php/topic,108814.msg894536.html
https://hydrogenaud.io/index.php/topic,109087.msg897207.html
https://hydrogenaud.io/index.php/topic,109628.msg902840.html
https://hydrogenaud.io/index.php/topic,98478.msg818228.html
https://hydrogenaud.io/index.php/topic,99629.msg825222.html
https://hydrogenaud.io/index.php/topic,99893.msg827068.html
https://hydrogenaud.io/index.php/topic,106213.msg868977.html
https://hydrogenaud.io/index.php/topic,106278.msg869353.html
https://hydrogenaud.io/index.php/topic,106434.msg870594.html
https://hydrogenaud.io/index.php/topic,106449.msg870740.html
https://hydrogenaud.io/index.php/topic,106825.msg873979.html
https://hydrogenaud.io/index.php/topic,111723.msg920609.html
Title: Re: How do "objective" audiophiles choose an amp?
Post by: John 31415926 on 2016-10-21 20:35:58
Man, I love this forum!  Completely unlike other audio forums that toss around subjective opinions of sound.  What a luxury that, in the case of audio, an objective measure of value mostly equates with significant cost savings.

Arnold B. Krueger wrote, "There are sub-$100 amps that are sonically ideal, well made, and last for a long time."

Can anyone mention a few company names or model lines to get me rolling?  I'm just coming out of the realm of magazine reviews and ads and don't know anything beyond popular and (apparently) overpriced amps.  It sounds from this thread as though just about *any* appropriately powered inexpensive amp will do the job ... but I suspect that there is still the issue of long-term reliability in the quality of the internal components.

I'm not trying to shirk my own research here.  I just haven't learned yet where to look for an amp that isn't steeped in illusions and subjective reputation.  All I know is glossy ads in magazines and Magnolia Best Buy.  I see plenty of good reviews on Amazon when I search for stereo amps and sort by low-price, but I can't tell a machine that is expected to last twenty years from one that might last four or five.  Longevity is almost never discussed in user reviews.

Or are most under-$200 amplifiers' build quality, like the sound quality, pretty much the same?

I run a pair of Martin Logan Motion 40's and will shortly add a subwoofer.  (I haven't learned yet if adding a sub affects the type of amp I need.)  I'm running toslink out of my Mac.  No other components, just the Mac.  I'd also like basic bass/treble knob tone control and a remote control for on/off and volume.

Because someone might ask ... I need a new amp because I'm currently running through a 5.1 home theater receiver that I want to relocate to a different part of the house where I watch movies.  The Mac/music corner will be in a different part of the house than the TV - so I want to get another amp just for the music.
Title: Re: How do "objective" audiophiles choose an amp?
Post by: 4season on 2016-10-21 23:47:24
Not everything's got to be done as cheaply as possible: I got no problems with someone paying extra for overkill (if properly engineered!) as long as they don't kid themselves that's it's about anything besides features, form-factors and of course, pure luxury. McIntosh? Mark Levinson? Sure, why not. These days, I'd want to see UL and FCC Class B ratings if for no other reason than to know that my boutique manufacturer wasn't cutting corners.

Even tube amps can be "pretty good", though relatively high-maintenance and best paired with speakers which present it with an easy-to-drive load (e.g., mostly resistive, above 4 ohms). The catch is that if you do it correctly, tubes and solid state really do sound the same  :))

Me, I've been there, done that. So these days aside from wanting to tinker once in awhile, I'm pretty much okay with choosing my gear from sources like B&H Photo. Or Best Buy. My next amp will probably be a 4-channel 1U Class D thing, probably by Crown or Behringer. Crown's a lot pricier but doesn't need a cooling fan. QSC's got some pretty amazing 2U amps but those can be a bit pricey and offer a lot of capabilities I may never use.
Title: Re: How do "objective" audiophiles choose an amp?
Post by: Northpack on 2016-10-22 08:46:57
I somehow have the impression that most "audiophiles" are trapped in a steam punk world of the massive 1970s Hi-Fi equipment they fetishize, pretending the relation of price, size and weight to sound quality and durability remained the same for 40 years, as if the digital revolution somehow didn't happen, or just affected the media, not the rest of the playback chain.

Well, there's nothing wrong about audiophile steam punk, I can absolutely understand its aesthetic appeal. The problem is when people don't admit to their fetish as such but make an occult science out of it. Instead of listening to music as the end of their equipment, the equipment is the end in itself and the music is merely an autosuggestive "placebo space" for imagining all those occult properties and nuances cunjured up by their magic equipment.

But it's up to anyone whether to dabble in this occult science of subjectivism or to enlight themselves about the current, objective state of science and technology and thereby become immune against all the phony marketing charms  ;)

Arnold B. Krueger wrote, "There are sub-$100 amps that are sonically ideal, well made, and last for a long time."

Can anyone mention a few company names or model lines to get me rolling?

This (https://www.amazon.com/Sound-Appeal-SA-100T-Digital-Amplifier/dp/B00E8ONRBS/) is one example of a 50 W stereo Class D amplifier the size of a cigarette box which is well build, totally transparent sounding and well under $100.
Title: Re: How do "objective" audiophiles choose an amp?
Post by: ajinfla on 2016-10-22 13:13:40
This (https://www.amazon.com/Sound-Appeal-SA-100T-Digital-Amplifier/dp/B00E8ONRBS/) is one example of a 50 W stereo Class D amplifier the size of a cigarette box which is well build, totally transparent
No.
(http://www.audiodevelopers.com/temp/TK2050.jpg)
Most inexpensive Class D have poor output filtering. If going Class D, stick with any of the Hypex or newer ICE chip designs.

I run a pair of Martin Logan Motion 40's and will shortly add a subwoofer.  (I haven't learned yet if adding a sub affects the type of amp I need.)  I'm running toslink out of my Mac.  No other components, just the Mac.  I'd also like basic bass/treble knob tone control and a remote control for on/off and volume.
Then you need only an amp that can drive a 4 ohm load, since your speakers have a 3.5 minima at 111hz (http://www.soundandvision.com/content/martinlogan-motion-40-speaker-system-ht-labs-measures#Mjec5ptyD3jXLMM0.97). There are countless of those without output filter issues. Something like this Yamaha (https://www.google.com/search?q=Yamaha+A-S301&oq=Yamaha+A-S301&aqs=chrome..69i57j69i60&sourceid=chrome&ie=UTF-8) for $300 new should do just fine.
Title: Re: How do "objective" audiophiles choose an amp?
Post by: Arnold B. Krueger on 2016-10-22 13:51:16
Man, I love this forum!  Completely unlike other audio forums that toss around subjective opinions of sound.  What a luxury that, in the case of audio, an objective measure of value mostly equates with significant cost savings.

Arnold B. Krueger wrote, "There are sub-$100 amps that are sonically ideal, well made, and last for a long time."

Can anyone mention a few company names or model lines to get me rolling? 

OK. "A few": Well-known mainstream audio brand AVR's such as Pioneer, Denon and Yamaha, and including their low and mid-end offerings. 

Quote
Or are most under-$200 amplifiers' build quality, like the sound quality, pretty much the same?

Both the same, and also completely adequate for the best possible sound quality.  There has been quite a bit of both improvement and standardization of actual parts quality.

Quote
I run a pair of Martin Logan Motion 40's and will shortly add a subwoofer.

Generally speaking adding a good subwoofer eases the load on your existing speakers and amps.

Quote
I'm running toslink out of my Mac.  No other components, just the Mac.  I'd also like basic bass/treble knob tone control and a remote control for on/off and volume.

Using the digital output of a Mac or PC as a sound source is a good route for high quality sound.

I'm surprised that you are unaware of the usual audiophile aversion for tone controls.
Title: Re: How do "objective" audiophiles choose an amp?
Post by: Northpack on 2016-10-22 13:55:24
This (https://www.amazon.com/Sound-Appeal-SA-100T-Digital-Amplifier/dp/B00E8ONRBS/) is one example of a 50 W stereo Class D amplifier the size of a cigarette box which is well build, totally transparent
No.
(http://www.audiodevelopers.com/temp/TK2050.jpg)
Ehem.. 2 ohms!? It's explicitly rated for 6-8 ohms, which should give a response -2 db at 20 kHz and about -0.5 dB at 10 kHz at worst. I don't think anyone could ever ABX that under real world conditions. That 7 ohm resonance is irrelevant because it is far beyond the audible spectrum. I agree though that for a 4 ohms load you probably want another amp.
Title: Re: How do "objective" audiophiles choose an amp?
Post by: Arnold B. Krueger on 2016-10-22 14:05:06
This (https://www.amazon.com/Sound-Appeal-SA-100T-Digital-Amplifier/dp/B00E8ONRBS/) is one example of a 50 W stereo Class D amplifier the size of a cigarette box which is well build, totally transparent
No.

Agreed.

Quote
(http://www.audiodevelopers.com/temp/TK2050.jpg)
Most inexpensive Class D have poor output filtering. If going Class D, stick with any of the Hypex or newer ICE chip designs.

The above seems to be a good example of an amp with poor output filtering. I suspect that I could set up an ABX test with younger listeners and they would be able to reliably detect this amp sounding different from many good traditional linear amps and receivers  while driving many common speakers.
Title: Re: How do "objective" audiophiles choose an amp?
Post by: Northpack on 2016-10-22 14:18:33
I suspect that I could set up an ABX test with younger listeners and they would be able to reliably detect this amp sounding different from many good traditional linear amps and receivers  while driving many common speakers.
Are you sure about that? AFAIK, most common speakers have a steady rise in impedance in the tweeter, often approaching an order of magnitude above the nominal impedance @ 20 kHz.
Title: Re: How do "objective" audiophiles choose an amp?
Post by: Arnold B. Krueger on 2016-10-22 16:00:54
I suspect that I could set up an ABX test with younger listeners and they would be able to reliably detect this amp sounding different from many good traditional linear amps and receivers  while driving many common speakers.
Are you sure about that?

Enough to entice me to take more test data and do a listening test.

Quote
AFAIK, most common speakers have a steady rise in impedance in the tweeter, often approaching an order of magnitude above the nominal impedance @ 20 kHz.

Hedge word: "Most"  noted.
Title: Re: How do "objective" audiophiles choose an amp?
Post by: ajinfla on 2016-10-22 16:18:12
Ehem.. 2 ohms!?
Or 1 to 3.5 like the popular Infinity 360~362
(http://www.stereophile.com/images/912Montisfig1.jpg)
(http://www.stereophile.com/images/archivesart/Infin360FIG1.jpg)
The amp you posted is an example of a non-transparent amp and one I wouldn't recommend for any low impedance loads.
I have a dead PE DTA-100 version if you're interested.

It's explicitly "rated" for 6-8 ohms
Right, which is why it has a 3.5 minima...measured.



Title: Re: How do "objective" audiophiles choose an amp?
Post by: 2tec on 2016-10-22 18:41:31
I just read my first ever article by an objective audiophile discussing the idea that all amps, within comparable parameters, do the same thing and sound the same, regardless of price. 
Isn't getting the adequate or "right" amount of power the idea behind getting the correct amp with the right "comparable parameters"? Doesn't the power requirements of the speakers figure in the choice of amplifiers?
Title: Re: How do "objective" audiophiles choose an amp?
Post by: greynol on 2016-10-22 18:50:32
Maximum power rating and sensitivity, yes.

Minimum and nominal requirements are bogus.

...already discussed in some of the links I gave as well as in numerous other threads.
Title: Re: How do "objective" audiophiles choose an amp?
Post by: Arnold B. Krueger on 2016-10-22 18:53:28
Isn't getting the adequate or "right" amount of power the idea behind getting the correct amp with the right "comparable parameters"? Doesn't the power requirements of the speakers figure in the choice of amplifiers?

Power is important, but it is not always the most important thing.

Ability to maintain flat frequency response at the amplifier output terminals with real world loudspeaker load impedance is more important, if for no other reason that it affects sound quality at all power levels.

The ability to deliver high power to speaker loads only matters at high SPLs, which may not even be ever be required.
Title: Re: How do "objective" audiophiles choose an amp?
Post by: krabapple on 2016-10-22 20:30:52
I don't use standalone poweramps,  but I choose *AVRs* mainly by features,e g.,  connectivity, DSP, codecs.  I have a 5.1 system so the subwoofer amplifier handles most of the bass.  Power considerations for the remaining channels --- all run as  'small' -- are not a huge deal.

No, I don't expect amps to 'sound different' otherwise, with the usual provisos.
Title: Re: How do "objective" audiophiles choose an amp?
Post by: RonaldDumsfeld on 2016-10-22 23:30:16
Quote
How do "objective" audiophiles choose an amp?

They don't. They buy active speakers instead.

After all ;  why not leave the, relatively trivial, task of designing the ideal amplifier for the specific crossover, driver and enclosure to the engineers responsible for the overall sound and quality of the bits at the sharp end?
Systems with active crossovers and individual amps fr each driver used to be regarded as high end and priced accordingly. Now you can get almost broadcast quality desktop monitors for less than $500 a pair. Even full scale systems need not cost more than $1000.

If you want to be absolutely sure you get the quality and reliability you need look at manufacturers that appeal  to the professional  market such as Genelec, Neumann, Focal, Adam or PSI. Althoigh to be honest the even less expensive alternatives are unlikely to disappoint.
Title: Re: How do "objective" audiophiles choose an amp?
Post by: Arnold B. Krueger on 2016-10-23 14:30:17
Quote
How do "objective" audiophiles choose an amp?

They don't. They buy active speakers instead.

Guilty as charged.   My main system's speakers are 3 x JBL Pro LSR 308  and 2 x 12" subwoofers - each has its own power amp.

Quote
After all ;  why not leave the, relatively trivial, task of designing the ideal amplifier for the specific crossover, driver and enclosure to the engineers responsible for the overall sound and quality of the bits at the sharp end?

The power amps in active speakers may be tolerant of what could otherwise be serious flaws in their design. If their frequency response is suboptimal based on their own design characteristics, the DSP-based active crossovers that the better active speakers contain can easily, stably, fully, and accurately compensate.

Quote
Systems with active crossovers and individual amps fr each driver used to be regarded as high end and priced accordingly. Now you can get almost broadcast quality desktop monitors for less than $500 a pair. Even full scale systems need not cost more than $1000.

I paid < $200 each for the LSR 308's, including shipping.  They are highly regarded by a goodly number of independent authorities, including the measurements that I did for myself.
Title: Re: How do "objective" audiophiles choose an amp?
Post by: KozmoNaut on 2016-10-23 15:29:04
Quote
How do "objective" audiophiles choose an amp?

They don't. They buy active speakers instead.

Guilty as charged.   My main system's speakers are 3 x JBL Pro LSR 308  and 2 x 12" subwoofers - each has its own power amp.

2x Adam A5X and 2x Dali SWA-12 subwoofers here, and DSP-based room correction+EQ. Couldn't be happier :-)
Title: Re: How do "objective" audiophiles choose an amp?
Post by: Ed Seedhouse on 2016-10-23 15:52:45
I just read my first ever article by an objective audiophile discussing the idea that all amps, within comparable parameters, do the same thing and sound the same, regardless of price.  I had never heard that before.  I had always bought into the idea that one amp surely sounded better than another.  It's still a little hard to get my head around the idea that a $4,500 Mcintosh amp has the same effect on an audio signal as a $400 Onkyo ... but that is the argument that these so-called objective articles and blind tests make. 

It's not an argument, it's a statement of measured fact.  It is what we observe, as opposed to what some people believe without evidence.
Title: Re: How do "objective" audiophiles choose an amp?
Post by: John 31415926 on 2016-10-23 19:53:51
The last paragraph above is phrased rather as though you dispute that "all amps sound the same". It's not really a belief that is "bought into", more a case of plain science.

It's not an argument, it's a statement of measured fact.  It is what we observe, as opposed to what some people believe without evidence.

That's the second such post, almost verbatim, to make this point on this thread.  Although the first one effectively continued on to articulate the whole concept point by point.

I don't want to inject a sour note into what has otherwise been a profitable and very helpful conversation (I really learn a lot from you guys) but hard statements like these sound to me as snobby and exclusive as subjective audiophiles sound fluffy and delusional.

The fact is, Ed, you may be speaking for yourself and a limited number of other people, but for me, it is not what "we" observe at all ... at least not yet.  I don't have time or interest (yet) to find a store that has all the low-end amps and all the high-end amps and do blind ABX tests for myself.  Nor do I even vaguely understand 80% of the specs referred to in this thread by people who are experienced and knowledgeable with audio measurements.  I know nothing about audio or electrical science.  So that shuts me out - at least at this point - of arriving at these conclusions by way of either blind listening tests or documented specs.

Perhaps hydrogenaudio is not a forum for amateurs or beginners in these matters?

I got to this point of asking what I consider to be more intelligent audio questions because someone wrote an article somewhere (maybe it was a post here on the forum) and made the simple statement that all an amp does is add electricity to an audio stream, thereby "amplifying" it, and, within the normal parameters, that's not a process that can be improved upon.

Therefore, all amps (given similar build quality and power specs) are equal. 

That was an argument someone had to walk me through, courteously and patiently, so I could follow it and finally agree - even without ever having any ABX or measured proof.  I know I can strengthen that conviction with listening tests or learning how to read these charts some of the other guys have presented here, but already now, I'm convinced by nothing more than a step-by-step argument presented by someone who didn't talk over my level of understanding or shut me out because I didn't understand "science".

You might even say that I believe this "without evidence".  I believe it because the argument makes sense.

Whenever I hear someone use a phrase like "the debate is over," or "this is a statement of measured fact" - without any regard for whether or not I've arrived at that conclusion for myself - I usually associate that kind of talk to someone who has no interest is winning me to the truth.

I'm 51 years old, reasonably intelligent, and only a few months ago was I ever exposed, for the first time ever, to the argument that all amps are basically the same.  I've since mentioned it around to a bunch of other people, and have yet to talk to even one person who has ever heard that argument before.  It seems the overwhelming number of people (at least people I've spoken to) have never given any thought to whether their amps were worth the money they spent.  They too were all about the subjective reputation of the brand name or the effectiveness of the advertisement.  Further, they've never even considered the simple idea that all an amp does is add electricity to an audiostream and that that is not a process that can be made "better" or "worse". 

The only reason I understand it now is because someone courteously argued it step by step until I understood it, without any measured specs and without two different amps around to compare.  I fully got it from just that.

And then, of course - after the fact - I can now read specs and do ABX tests all I want until the understanding is bullet-proof.

So a big THANK YOU to all the posters who go the distance and do the work to walk a guy through this stuff so I can benefit from your knowledge, even long before I completely understand it.  It will be a while before I can talk intelligently on your level, but I'm already now feeling good about spending around $1,800 less on an amp than I otherwise would have ... and I'm already feeling confident about the amp I will choose.

I really am humbled by the work some of you put into a post to help me understand something.

Case in point:

Then you need only an amp that can drive a 4 ohm load, since your speakers have a 3.5 minima at 111hz (http://www.soundandvision.com/content/martinlogan-motion-40-speaker-system-ht-labs-measures#Mjec5ptyD3jXLMM0.97). There are countless of those without output filter issues. Something like this Yamaha (https://www.google.com/search?q=Yamaha+A-S301&oq=Yamaha+A-S301&aqs=chrome..69i57j69i60&sourceid=chrome&ie=UTF-8) for $300 new should do just fine.

ajinfla, I don't understand any of those specs, but I've got enough faith in what you're talking about to use your recommendation.  The Yamaha AS301 looks like everything I want - bass/treble, remote control, reputable manufacturer - and, I assume, a correct match for my speakers.  Thanks for bringing this to my attention.



Title: Re: How do "objective" audiophiles choose an amp?
Post by: greynol on 2016-10-23 22:01:06
ajinfla, I don't understand any of those specs, but I've got enough faith in what you're talking about to use your recommendation.  The Yamaha AS301 looks like everything I want - bass/treble, remote control, reputable manufacturer - and, I assume, a correct match for my speakers.  Thanks for bringing this to my attention.
Don't overlook the variable loudness control.  I have an RX-460 which I purchased over 20 years ago and is still in use today.  I also have an RX-770 which allows access to the variable loudness control via the remote, though I normally also have to adjust the treble (along with the volume) when adjusting the loudness which isn't on the remote. :(

These receivers were made in Japan.  Time will tell whether or which products made in China will fare as well.  This isn't to say that I'm all that pleased with a certain guitar amplifier company in England for using cheap epoxy boards (http://www.electronicspoint.com/threads/marshall-jcm-2000-dsl-of-2003.245571/) and not plating their through-holes.
Title: Re: How do "objective" audiophiles choose an amp?
Post by: Ed Seedhouse on 2016-10-24 00:10:55
The fact is, Ed, you may be speaking for yourself and a limited number of other people, but for me, it is not what "we" observe at all ... at least not yet. 

May I suggest the terms of use of this forum, *to* *which* *you* *agreed* in order to be permitted to post here.  Are you a person of your word or not?  Did you not read the terms of service before agreeing to them, and if not, why not?
Title: Re: How do "objective" audiophiles choose an amp?
Post by: greynol on 2016-10-24 00:37:46
The fact is, Ed, you may be speaking for yourself and a limited number of other people, but for me, it is not what "we" observe at all

May I suggest the terms of use of this forum, *to* *which* *you* *agreed* in order to be permitted to post here.  Are you a person of your word or not?  Did you not read the terms of service before agreeing to them, and if not, why not?
I think what Ed is trying to say that your concept of "a limited number of other people" refers to this forum as a collective body which requires "observations" of perceived differences in sound quality to be supported by objective evidence.

*We* (hydrogenaudio) are not interested in what others "observe" or parrot if it doesn't comply with TOS8.

at least not yet.
Hopefully sooner than later.  It would be a shame that your lack of acceptance of the need for requiring proper controls is being held up because you're put off by statements you deem to be "snobby and exclusive."

... but that is the argument that these so-called objective articles and blind tests make.
You probably don't realize it, but there are people who find this somewhat offensive.
Title: Re: How do "objective" audiophiles choose an amp?
Post by: andrew_berge on 2016-10-24 01:00:19
My understanding of John's statement is that he has neither the equipment nor the knowledge necessary to test and make those observations, not that he disagreed with them.
Title: Re: How do "objective" audiophiles choose an amp?
Post by: John 31415926 on 2016-10-24 01:05:38
My understanding of John's statement is that he has neither the equipment nor the knowledge necessary to test and make those observations, not that he disagreed with them.

Thank you, Andrew.

Spot on.
Title: Re: How do "objective" audiophiles choose an amp?
Post by: greynol on 2016-10-24 01:08:14
My understanding of John's statement is that he has neither the equipment nor the knowledge necessary to test and make those observations, not that he disagreed with them.
Spot on.
I come at this from a different perspective: one shouldn't need the equipment or knowledge to test in order to be skeptical of unsubstantiated claims; rather, one needs to understand that the human perception of sound is fallible (https://www.youtube.com/watch?v=G-lN8vWm3m0).
Title: Re: How do "objective" audiophiles choose an amp?
Post by: ajinfla on 2016-10-24 02:13:14
Therefore, all amps (given similar build quality and power specs) are equal.
No.
There is an example provided in this thread why that isn't so and why no technically literate person would claims so.
What can be said, is with linear amplifiers, not driven to clipping or instability into the load (speaker), no audible difference will be heard by ears. Barring pathological loudspeakers, there are a great many amplifiers out there that "amplify", rather than possess a "sound". Given your particular speakers, one such example is posited.

ajinfla, I don't understand any of those specs, but I've got enough faith in what you're talking about to use your recommendation.  The Yamaha AS301 looks like everything I want - bass/treble, remote control, reputable manufacturer - and, I assume, a correct match for my speakers.  Thanks for bringing this to my attention.
Unless you plan to listen at very high levels, it should be more than suffice. If you listen to radio, something like this (https://www.google.com/search?q=R-S500&oq=R-S500&aqs=chrome..69i57j69i60&sourceid=chrome&ie=UTF-8) or this (https://www.google.com/search?q=R-N500&oq=R-N500&aqs=chrome..69i57j69i60l3&sourceid=chrome&ie=UTF-8) could be an option.
Title: Re: How do "objective" audiophiles choose an amp?
Post by: ajinfla on 2016-10-24 02:16:13
My understanding of John's statement is that he has neither the equipment nor the knowledge necessary to test and make those observations, not that he disagreed with them.
I don't have a rocket to fly to the moon to see if it's made out of cheese either, per "observation"
Title: Re: How do "objective" audiophiles choose an amp?
Post by: John 31415926 on 2016-10-24 02:36:06
Unless you plan to listen at very high levels, it [Yamaha A-S301] should more than suffice. If you listen to radio, something like this (https://www.google.com/search?q=R-S500&oq=R-S500&aqs=chrome..69i57j69i60&sourceid=chrome&ie=UTF-8) could be an option.

Thank you, AJ.  Interesting that the amp with the receiver costs the exact same price as the AS301 you originally posted.  For the same money, of course I would take the unit with the radio included.

Again, I don't understand audio specs ... so can I borrow your expertise on this?  Again, specific to my Martin Logan Motion 40s, are there any other differences that I might concern myself with on these two units (the AS301 vs RS500)...?  It seems like the RS500 is a no-brainer since I get the added benefit of a radio receiver.  But I wonder if it has any other shortcomings (over the AS301) that offset that benefit?
Title: Re: How do "objective" audiophiles choose an amp?
Post by: ajinfla on 2016-10-24 02:56:01
Again, I don't understand audio specs ... so can I borrow your expertise on this?  Again, specific to my Martin Logan Motion 40s, are there any other differences that I might concern myself with on these two units (the AS301 vs RS500)...?  It seems like the RS500 is a no-brainer since I get the added benefit of a radio receiver.  But I wonder if it has any other shortcomings (over the AS301) that offset that benefit?

Dr Floyd Toole once made the observation that there is more useful performance information on the side of a tire, compared to what’s currently found on most loudspeaker spec sheets. I did not quote a "spec" for your ML, by rather an independently measured parameter, the impedance minima, including frequency. As such either one of those amps would suffice as an "amplifier", the inclusion of more features such as radio, would perhaps increase the value of the latter.
Again, unless your listening requirements are for very high levels, both will "amplify" your around 90db sensitivity speakers  just fine.
Title: Re: How do "objective" audiophiles choose an amp?
Post by: John 31415926 on 2016-10-24 03:44:45
Thank you, AJ.

I'm off to Amazon to buy the RS500.

-JOHN
Title: Re: How do "objective" audiophiles choose an amp?
Post by: greynol on 2016-10-24 03:49:12
I'm surprised that you are unaware of the usual audiophile aversion for tone controls.
I don't see how one can get satisfactory results over a variety of listening levels without tone controls.

I'm also unaware of any omniscient audiophiles who are able to reproduce the proper listening level and environment in order to achieve what was heard in the studio.
Title: Re: How do "objective" audiophiles choose an amp?
Post by: John 31415926 on 2016-10-24 06:11:06
Hey John, what happened to your Onkyo?

I'm swapping it out for a Yamaha.

Those Onkyo amps just don't sound as warm, persuasive, and colorful as a good Yamaha.
Title: Re: How do "objective" audiophiles choose an amp?
Post by: greynol on 2016-10-24 06:25:30
I don't know much about audio, but I do a hear a BIG difference in different amps, so I'll be shopping quality amps soon
THANK YOU for taking the time to help me and save me from making a costly decision that would not have solved my problem.
Good, I'm glad to see you did come to your senses.
Well maybe not for another 6 months.

Hey John, what happened to your Onkyo?
I'm swapping it out for a Yamaha.

Those Onkyo amps just don't sound as warm, persuasive, and colorful as a good Yamaha.
Surely you must be joking by now.

Title: Re: How do "objective" audiophiles choose an amp?
Post by: John 31415926 on 2016-10-24 06:37:35
Surely you must be joking by now.

Please don't call me Surely.
Title: Re: How do "objective" audiophiles choose an amp?
Post by: greynol on 2016-10-24 06:52:28
Well that was predictable.  So were you serious or were you kidding?
Title: Re: How do "objective" audiophiles choose an amp?
Post by: John 31415926 on 2016-10-24 07:17:34
I love it!  I've got greynol worked up, not knowing if I've violated the rules or not.  The poor guy's on the edge of his seat, ready to slap me down or ban me if I say that Yamaha amps are more "warm, persuasive, and colorful" as Onkyos ... even after all the rational exchange of this thread.  Hilarious!

 :))

Don't worry, greynol ... you were being a wiseguy by unlocking and remarking on an unenlightened six month old comment I made about amps ... so I returned in kind.

Yes, I was only kidding.  Although I have yet to AB test them myself ... and even though I don't understand a single graph that might prove it numerically ... I'm convinced that no human ear can discern the difference between a similarly spec'd Onkyo and Yamaha.

Happy?     ;)

Title: Re: How do "objective" audiophiles choose an amp?
Post by: greynol on 2016-10-24 07:30:10
Let's just say you wouldn't have been the first person to waffle between rational and irrational thought and your opening post had global-warming denier written all over it. ;)

Title: Re: How do "objective" audiophiles choose an amp?
Post by: John 31415926 on 2016-10-24 07:50:14
Boy, you just give people warm fuzzies with every post, greynol.

Some day I'll understand the frequent connection between higher knowledge and the loss of basic courtesy.  Then again, I might not really care to.  I recall in my own past when it felt good to be snarky and sarcastic, but I never really liked myself for it afterwards.

I guess some guys are wired for that and others aren't.

Anyway, I got my amp question answered and AJ helped choose my next amp for me. 

I got what I came here for.   8)

Title: Re: How do "objective" audiophiles choose an amp?
Post by: greynol on 2016-10-24 08:09:18
You'll like the Yamaha, unless that little voice inside your head says you didn't spend enough money. ;)
Title: Re: How do "objective" audiophiles choose an amp?
Post by: Arnold B. Krueger on 2016-10-24 14:23:17
Boy, you just give people warm fuzzies with every post, greynol.

Some day I'll understand the frequent connection between higher knowledge and the loss of basic courtesy.  Then again, I might not really care to.  I recall in my own past when it felt good to be snarky and sarcastic, but I never really liked myself for it afterwards.

I guess some guys are wired for that and others aren't.

Anyway, I got my amp question answered and AJ helped choose my next amp for me. 

I got what I came here for.  8)



What I see is that the poster who posts under the pseudonym John is now congratulating himself for his elaborate attack on all of  Hydrogen Audio by means of ridiculing Greynol.  Sincerity and honesty = 0.0000 .
Title: Re: How do "objective" audiophiles choose an amp?
Post by: antz on 2016-10-24 14:48:45
The last paragraph above is phrased rather as though you dispute that "all amps sound the same". It's not really a belief that is "bought into", more a case of plain science.

It's not an argument, it's a statement of measured fact.  It is what we observe, as opposed to what some people believe without evidence.

That's the second such post, almost verbatim, to make this point on this thread.  Although the first one effectively continued on to articulate the whole concept point by point.

I don't want to inject a sour note into what has otherwise been a profitable and very helpful conversation (I really learn a lot from you guys) but hard statements like these sound to me as snobby and exclusive as subjective audiophiles sound fluffy and delusional.

For my part, it was not my intention to sound snobby and exclusive. It was merely an observation that your phrasing implied that you do not believe the evidence. If you reject the evidence after considering it, then you should provide evidence to the contrary. If you aren't sure about accepting it because you don't understand it, that's not something I'd criticise you for.
Title: Re: How do "objective" audiophiles choose an amp?
Post by: 4season on 2016-10-24 19:02:12
A proper power amp ABX may be a bit tricky to set up, requiring a bit of hardware which you may never care to use again.

But you can certainly test the basic premise of such testing using line-level source components. In my case, I happened to have a couple of FM tuners. Plug each into a line-level input such that you can switch between them with a minimum of fuss.

Now here's the absolutely essential part: Level matching! I believe the standard for such things is to keep things within 0.1 db of each other. But I also recall a quote from Stereo Review's Larry Klein to the effect that this can be done by ear, and you know you've got it when you can no longer hear differences! If you want to do it double-blind, you might have someone else do the switching for you, but you may not need to go that far to experience a revelation.

If you are going with a receiver or integrated amplifier, may I suggest one which has a tape loop or other handy input/output jacks were an equalizer or MiniDSP can be inserted?  It'd be a rare speaker + room combo which doesn't benefit greatly from some correction. Would be super-handy if you could just use the room correction that's built into cinema receivers, but these functions may not be available unless you've got all 5.1 channels connected, at least that was true of my old Harman Kardon.
Title: Re: How do "objective" audiophiles choose an amp?
Post by: John 31415926 on 2016-10-24 20:06:17
For my part, it was not my intention to sound snobby and exclusive. ... If you aren't sure about accepting it because you don't understand it, that's not something I'd criticize you for.

In hindsight, I should not have quoted your comment when I made that post, Antz.  In fact, you continued right on with a thorough point-by-point explanation which in fact was the opposite of "snobby and exclusive".  Taken out of context, your comment sounded similar to Ed's, but you were kind enough to continue right on and took time to help me understand the arguments and added that there are in fact badly built amps to be avoided. 

Sometimes I wish that the "quick edit" button still stayed with a post hours or days later - especially now that I see that quoting your post was not really an accurate example of my complaint about people who sniff at other people's various level of understanding with dismissive "it's settled science, the debate is over, you're obviously ignorant" kind of comments.

I've always interpreted short, curt comments like that as someone trying to flaunt his own understanding and gratify his ego, rather than genuinely trying to help the next guy out ... but that might just be my interpretation.

Either way, quoting you out of the broader context of your helpful comments wasn't appropriate and I apologize if I lumped you in with the "snobby and exclusive" comment.
Title: Re: How do "objective" audiophiles choose an amp?
Post by: John 31415926 on 2016-11-16 00:59:58
AJ ... I wonder if you're still checking this thread.  I procrastinated buying the Yamaha R-S500 amp you recommended three weeks ago and only now finally sat down, credit card in hand, and went to Amazon to order the thing. 

I really appreciated the straight recommendation without too much spec-talk, as I don't understand much about what kind of wattage is appropriate for a certain speaker ... and I know nothing about ohms, hertz, etc.  It would be a lot of homework and a steep learning curve if I have to choose my next amp myself.  Much of this thread went right over my head.

You recall I'm replacing an Onkyo 5.1 amp which I've been using as my stereo amp.  I listen to music from my Mac going to the Onkyo via digital optical ... and my Onkyo has two digital optical inputs. 

As far as I can tell, the R-S500 you recommended has no digital optical inputs. 

To further complicate matters, I realize now that I can actually use two digital optical inputs because I have my Mac on my desk, which I use for recorded music ... and behind me in the same room, I have music keyboards that I want to hook up to a separate laptop to play software synthesizers.  That would create another optical out from the laptop.

I could just google stereo amps with two digital inputs, but then I'm back to not knowing what I'm doing with regard to the specs that are appropriate for my Martin Logan Motion 40's.

I also really liked that the receiver you recommended had basic tone controls (I would use those constantly) and almost no embedded menus.  A real 70's looking "everything out front" amp.  My Onkyo is a drag because it's made to amplify a 5.1 video system, with all controls displayed on an HDTV screen. 

Does an amp like the R-S500 - but with two digital optical ins - come to mind?  Again, keeping in mind the demands of Martin Logan Motion 40 speakers (https://www.martinlogan.com/pdf/brochures/brochure_motion40.pdf).  (Click for specs.)

If two optical ins is rare or unheard of for a stereo amp, is there an amp like the R-S500 with one input that you can recommend?





Title: Re: How do "objective" audiophiles choose an amp?
Post by: greynol on 2016-11-16 03:45:39
AJ already gave you a link to a receiver with two optical inputs.
Title: Re: How do "objective" audiophiles choose an amp?
Post by: John 31415926 on 2016-11-16 04:43:54
AJ already gave you a link to a receiver with two optical inputs.

You're right.  The Yamaha R-N500BL.  I was so focused on the one I had chosen, I forgot that there were a couple other links in AJ's posts.

That model is discontinued, though.  I'm sure there's got to be a recent one that has the same features. 

Greynol ... if you don't mind me asking you since you read all the posts ... when I read that digital optical is supposed to sound better than analog outs (for stereo), is that improvement something that the serious listeners who post on HA would agree is readily discernible?  Or is that improvement one of those "I can tell the difference between FLAC and 320kpbs" kind of things, i.e. better in theory but indistinguishable in practical reality?




Title: Re: How do "objective" audiophiles choose an amp?
Post by: greynol on 2016-11-16 08:05:28
when I read that digital optical is supposed to sound better than analog outs (for stereo), is that improvement something that the serious listeners who post on HA would agree is readily discernible?
Optical is good for eliminating ground loops.  If there is audible hum with an analog connection, but not with an optical connection then clearly the optical connection will sound better.

If there isn't a problem with audible hum, and both of the DACs being compared are competently designed, then they will be indistinguishable.

It is best not to draw an analogy with lossy compression or try to shoehorn the situation into some esoteric "theoretical" category.  Psychoacoustics and hardware are apples and oranges.
Title: Re: How do "objective" audiophiles choose an amp?
Post by: John 31415926 on 2016-11-16 08:08:43
If there isn't a problem with audible hum, and both of the DACs being compared are competently designed, then they will be indistinguishable.

Thanks, Greynol.
Title: Re: How do "objective" audiophiles choose an amp?
Post by: Arnold B. Krueger on 2016-11-16 13:46:22
Does an amp like the R-S500 - but with two digital optical ins - come to mind?  Again, keeping in mind the demands of Martin Logan Motion 40 speakers (https://www.martinlogan.com/pdf/brochures/brochure_motion40.pdf).  (Click for specs.)

If two optical ins is rare or unheard of for a stereo amp, is there an amp like the R-S500 with one input that you can recommend?

Coax and optical (AKA toslink)  inputs and outputs generally pass the identical same data, so it is the transport mechanism (light based versus electrical current) that varies. Thus  inexpensive black boxes that interconnect the two are readily available.  Google "toslink coax converter"   (without quotes) and be rewarded with many options , of which even the most inexpensive have no audible impact on the signal.

Similiarly, googling on "toslink splitter"  (again no quotes on the actual search) will reward you with many options for increasing the number of optical outputs available in your system.
Title: Re: How do "objective" audiophiles choose an amp?
Post by: John 31415926 on 2016-11-17 01:13:48
Does an amp like the R-S500 - but with two digital optical ins - come to mind?  Again, keeping in mind the demands of Martin Logan Motion 40 speakers (https://www.martinlogan.com/pdf/brochures/brochure_motion40.pdf).  (Click for specs.)

If two optical ins is rare or unheard of for a stereo amp, is there an amp like the R-S500 with one input that you can recommend?

Coax and optical (AKA toslink)  inputs and outputs generally pass the identical same data, so it is the transport mechanism (light based versus electrical current) that varies. Thus  inexpensive black boxes that interconnect the two are readily available.  Google "toslink coax converter"   (without quotes) and be rewarded with many options , of which even the most inexpensive have no audible impact on the signal.

Similiarly, googling on "toslink splitter"  (again no quotes on the actual search) will reward you with many options for increasing the number of optical outputs available in your system.

You seem to understand why I asked about optical vs RCA.  I haven't looked at every amp on the market yet, but of the few that I looked at, one optical input shows up on an amp that is around $300.  No problem there.  For two optical inputs, the cheapest amp I've seen is $600.  No bueno.  This was, after all, a thread about spending only as much as needed for a well built amp - and not more. 

That's why I asked about optical vs RCA.  If I have two sound sources going into the amp, but only have one optical input, then I can use RCA for the other, if the difference in sound quality is indistinguishable.  I'm willing to just take Greynol's word for that; you guys get around these things much more than I do.  Thanks too for the suggestion to look at TOSLink to coax converters.  I didn't know there was such a thing.  I've never used coax before and have no idea why it exists as something separate from RCA.  Yet more reading, I guess, to learn about that.

I know there is nothing inherently expensive about two optical inputs.  My cheapie Onkyo amp right now has two optical inputs (plus coax and multiple HDMIS) and it cost me only $399 for the amp *with* all the 5.1 speakers.  Everything works great on this thing.  But again, this amp has embedded menus that require a TV screen, no tone control knobs, etc ... not ideal for a music corner. 

Otherwise, I would just go out and get another one of these.

Jeez, I really like the vintage 70's look of these newer Yamaha amps, the one AJ recommended.  That's what amps looked like when I was young and beautiful ... and they seem to work right at my level of understanding about audio gear.  Nothing at all confusing about this interface.

(http://data.yamaha.jp/sdb/product/image/main/raw/a/a-s501_silver/C16F0F418BB745F49102B5E9C3843ACC_12073.jpg)
Title: Re: How do "objective" audiophiles choose an amp?
Post by: KozmoNaut on 2016-11-17 12:42:55
If you need additional optical inputs, you can just get a small toslink DAC and run that into an RCA input.

Or you could get a toslink splitter, though I would personally prefer an active toslink switch rather than a splitter. A simple splitter is really nothing more than a couple of pieces of plastic and some lenses, and you manually move a knob to select a different signal. An active switch does the switching electronically, and most come with a handy remote control.
Title: Re: How do "objective" audiophiles choose an amp?
Post by: John 31415926 on 2016-11-17 17:22:23
If you need additional optical inputs, you can just get a small toslink DAC and run that into an RCA input.

Good suggestion, but adaptors and converters would be my last resort.  I haven't looked at Onkyo amps yet.  If my 5.1 Onkyo has two opticals, perhaps their stereo amps do too.
Title: Re: How do "objective" audiophiles choose an amp?
Post by: Nichttaub on 2016-11-18 00:55:31
This (https://www.amazon.com/Sound-Appeal-SA-100T-Digital-Amplifier/dp/B00E8ONRBS/) is one example of a 50 W stereo Class D amplifier the size of a cigarette box which is well build, totally transparent
No.
(http://www.audiodevelopers.com/temp/TK2050.jpg)
Most inexpensive Class D have poor output filtering. If going Class D, stick with any of the Hypex or newer ICE chip designs.


I have one of these, and while it may not be a great amp, it works well in my workshop driving both 4 and 8 ohm speakers at satisfying volume.  I don't want a huge receiver or component amp when all I need is 30-40 Watts out and a line level in, 2 channels.  Are there any small amps with quality chip sets that don't cost $300?
Title: Re: How do "objective" audiophiles choose an amp?
Post by: ajinfla on 2016-11-18 13:10:43
I have one of these, and while it may not be a great amp, it works well in my workshop driving both 4 and 8 ohm speakers at satisfying volume.  I don't want a huge receiver or component amp when all I need is 30-40 Watts out and a line level in, 2 channels.
Right. I have several of these types (Dayton, Lepai, etc) and use them with regularity, given their small, portable but potent nature.
My only contention was the statement that they were an example of a "transparent' amp. They are not. However, that doesn't make them junk. To the contrary, as long as one understands the nature of the output filtering vs load and the slight very HF variations, it can be no big deal at all. Under many circumstances, it may be difficult if not impossible to detect. That's why I use them.

Are there any small amps with quality chip sets that don't cost $300?
Aside from these Class D types, yes, but no ICE or Hypex that I'm aware of. There could very well be some based on newer chip designs that don't exhibit this type of filtering issue as shown. Or a non class D like this LM based design (http://www.ebay.com/itm/40W-40W-LM3886-mini-amplifier-machine-home-audio-amplifier-machine/322326834871?_trksid=p2047675.c100011.m1850&_trkparms=aid%3D222007%26algo%3DSIC.MBE%26ao%3D1%26asc%3D38530%26meid%3D6f980788e1e24e48b8073f506880dc30%26pid%3D100011%26rk%3D1%26rkt%3D12%26sd%3D162112760568)

cheers
Title: Re: How do "objective" audiophiles choose an amp?
Post by: Arnold B. Krueger on 2016-11-18 13:47:53
This (https://www.amazon.com/Sound-Appeal-SA-100T-Digital-Amplifier/dp/B00E8ONRBS/) is one example of a 50 W stereo Class D amplifier the size of a cigarette box which is well build, totally transparent
No.
(http://www.audiodevelopers.com/temp/TK2050.jpg)
Most inexpensive Class D have poor output filtering. If going Class D, stick with any of the Hypex or newer ICE chip designs.

I have one of these, and while it may not be a great amp, it works well in my workshop driving both 4 and 8 ohm speakers at satisfying volume.  I don't want a huge receiver or component amp when all I need is 30-40 Watts out and a line level in, 2 channels.  Are there any small amps with quality chip sets that don't cost $300?

The most severe problem with these amps that typically leads to their non-transparency is more their typically rising frequency response due to their relatively high source impedance at high frequencies combined with the typically rising high frequency impedance of tweeters..

For example, if you use these with appropriate equalization or with speakers with moderate to excessive high frequency losses, they can sound pretty good.

With careful equalization, a restoration of transparency is possible.  So switchmode receivers with built-in self-adjusting equalization like Audyssey can work out quite well.
Title: Re: How do "objective" audiophiles choose an amp?
Post by: Arnold B. Krueger on 2016-11-20 14:04:52
The most severe problem with these amps that typically leads to their non-transparency is more their typically rising frequency response due to their relatively high source impedance at high frequencies combined with the typically rising high frequency impedance of tweeters..

For example, if you use these with appropriate equalization or with speakers with moderate to excessive high frequency losses, they can sound pretty good.

With careful equalization, a restoration of transparency is possible.  So switchmode receivers with built-in self-adjusting equalization like Audyssey can work out quite well.


Also, the common but not universal practice of terminating the input to the speaker with a Zobel  could be a great and perhaps even audible benefit.

Article about correcting speaker impedance curve with a zobel. (https://trueaudio.com/st_zobel.htm)
Title: Re: How do "objective" audiophiles choose an amp?
Post by: Nichttaub on 2016-11-22 03:35:22
Thanks, all.  Looks like the LM3886 chipset is one to keep an eye open for; and I don't have to have a Class D so I'm happy to try others.  Though I love the Ebay listing with the amp whose volume control is labeled "MIN ... MXA".   :D

Title: Re: How do "objective" audiophiles choose an amp?
Post by: Arnold B. Krueger on 2016-11-22 13:24:02
Thanks, all.  Looks like the LM3886 chipset is one to keep an eye open for; and I don't have to have a Class D so I'm happy to try others.  Though I love the Ebay listing with the amp whose volume control is labeled "MIN ... MXA".   :D

Potentially a good choice. I've seen 3886's in the schematics of a numer of highly regarded active speakers such as:

http://schematicscom.blogspot.com/2016/08/behringer-b2031-schematic-active-2-way.html

Vendor guidelines for use and reasonable expectations for performance:

http://www.ti.com/lit/an/snaa021b/snaa021b.pdf

http://www.ti.com/lit/an/sloa068/sloa068.pdf
Title: Re: How do "objective" audiophiles choose an amp?
Post by: 4season on 2016-11-22 16:13:34
S. Linkwitz has published some measurements of various amps, and I'm pretty impressed with how well the Hypex and LM3886 designs stack up.

http://linkwitzlab.com/Amplifiers-etc/Distortion.htm (http://linkwitzlab.com/Amplifiers-etc/Distortion.htm)