Why do different amps sound so different?

[Superampman]

Do you consider consumer feedback as a spec, of sorts?

This is more pertinent than meets the eye here. Since the demolition of brick and mortar venues, all we really have is research. Every single piece of gear I have aside from my first system I demoed in '78, is acquired via the net. That very first system painstakingly routed out back then is my reference. A pair of KEF 105.2, a pair of Meridian 105 monos with matching pre, and an Oracle Alexandria TT with Dynavector Ruby. I have been to a couple of shops since then but the gear I've acquired in addition has been over the last ten years. In comparison, I would say I'm a pretty good shopper- Bedini, G.A.S., Linn, Acoustat, HK, SAR Labs, JBL, Infinity. However all vintage used gear with track record.

 

[stereofanboy]

......I don't even bother to check specs on gear (other than output power for power amplifiers) anymore. In the last 25+ years everything I've considered buying has good to great specs.

In reading these two sentences you can see that they beg the question, do you have psychic powers?

Specs are going to have to be good before I even consider paying attention. There is a baseline after all, no? Mind you that base line may consist of consumer feed back also. So not necessarily ultra high specs.

That sort of baseline can be especially helpful if there is considerable effort required for auditioning gear, like for someone who doesn't live within a few hours drive of a stereo shop.

........I've been posting on various site long enough to know who the various "fan boys" are........

Hey, I resemble that remark!

 

[JoeESP9]

Do you consider tube amplification to be more advantageous for low impedance speakers Joe?

Not necessarily. Tubed amplifiers (to my ears) sound better than SS when driving my current speakers. I can't/won't comment about speakers I don't own and listen to.

A while back a Krell KSA-50 driving a pair of Magnepan MG-3a's was better than everything else I was able to try, tubed or solid state. The Krell and the Maggies were mine.

A divorce necessitated my selling that Krell. It's something I still regret.

 

[ConradH]

I'm a great believer of that premise too, but my latest discovery on my pair of big Sony TAN77es power amps has me scratching my head.

They are 430 apart in serial numbers, all the components are identical. Both are multivoltage units with no EU filtering. Both pull the same current from the wall and are running secondary rails within a volt or two of each other.

One is an ex Sony dealers demonstration unit, the other came from a Sony State manager's own collection.

They are both in excellent condition. Both test identically on my bench. Ruler flat to over 300kHz, distortion is below what I can measure (<0.001%) and power outputs are identical into 8 ohms. 4 ohm power output was difficult to measure due to my dummy loads getting close to destruction.

Intermodulation plots reveal nothing between them.

With a 100Hz, 3kHz, 10kHz square wave, their reproduction was identical. (I use a square wave to sort out my amps in short order).

So it isn't transient, rise, fall, power, response in the bottom or top ocataves, power bandwidth or anything I can test.

They sound different. I swear. The ex demo unit sounds better than the ex Sony Sate Manager's unit. The demo unit had a lot more hours on it.

I will try to record the difference by padding down the tapped off output into a DAT recorder and posting the files (when I get a chance)

I have subsequently tried several other pairs of identical amps (yes I have way too much gear) and subtle differences exist. (bear in mind I trim the flatness of each amp using a square wave and the tone controls where a tone bypass doesn't exist- this is very important in older amps as their response is usually far from flat when bass and treble are in the flat position)

Send them the same signal (both music and test signals) and use actual speakers for the load. Make a differential scope measurement from hot to hot. Also do it from ground to ground, just so you never have to think about it again. Bet you find the signals aren't identical. If the signals are the same within a dozen mV, the listening test is suspect. I've experienced the same thing and eventually did uncover some setup and speakers issues that were fooling me.

 

[JoeESP9]

In reading these two sentences you can see that they beg the question, do you have psychic powers?

I wish! I am only interested in separates and their specs have been exemplary for years.

That sort of baseline can be especially helpful if there is considerable effort required for auditioning gear, like for someone who doesn't live within a few hours drive of a stereo shop.

I live in Phila. and have ridden the train to NYC and DC to audition gear. So the "excuse" it's to far away to audition doesn't work with me.

Hey, I resemble that remark!

No offense intended.

 

[davidro]

A divorce necessitated my selling that Krell. It's something I still regret.

Ouch

 

[TubeHiFiNut]

This is more pertinent than meets the eye here. Since the demolition of brick and mortar venues, all we really have is research. Every single piece of gear I have aside from my first system I demoed in '78, is acquired via the net. That very first system painstakingly routed out back then is my reference. A pair of KEF 105.2, a pair of Meridian 105 monos with matching pre, and an Oracle Alexandria TT with Dynavector Ruby. I have been to a couple of shops since then but the gear I've acquired in addition has been over the last ten years. In comparison, I would say I'm a pretty good shopper- Bedini, G.A.S., Linn, Acoustat, HK, SAR Labs, JBL, Infinity. However all vintage used gear with track record.

If I may ask, how do you compile your 'short list' of components and then how do you go about making your final selections?

 

[Superampman]

If I may ask, how do you compile your 'short list' of components and then how do you go about making your final selections?

Sure. It's not a hunt I'm on or a list I've compiled. It's just chatter that catches my attention. Interest in the hobby is what drives it, facilitated by the net. For example I acquired a Bedini 100/100 around 10 years ago, the first additional piece since the 80's. I remembered the hyperbole back then about them when someone brought it up on a forum thread. Hmm I thought:scratch2:, I think I'm gonna get me one of those. So in the course of hunting one down(I suppose it is a hunt once my interest is aroused), I came across lots of opinions and specs confirming I want it. I've since bought and sold a 25/25, 150MKII, and a 250/250. I still have the 100/100, the best by far. A bit sluggish sounding but very musical. It actually has a holographic sound stage. Gimme Shelter is spooky with it. Happened the same way with everything else. Simple, eh? Mind you without the net, aka this forum and others, it wouldn't have happened at all.

 

[stereofanboy]

..........I live in Phila. and have ridden the train to NYC and DC to audition gear. So the "excuse" it's to far away to audition doesn't work with me........

Were those the nearest stereo shops to you, or just the nearest ones that carried the item you wanted to hear?

It's only a few miles short of twice as far to the nearest stereo shop I know of from me as the Philly to DC trip you made. Of course I can't talk since it's been years since I've been to Louisiana where I've only recently heard they still have a real stereo shop.

 

[TubeHiFiNut]

Sure. It's not a hunt I'm on or a list I've compiled. It's just chatter that catches my attention. Interest in the hobby is what drives it, facilitated by the net. For example I acquired a Bedini 100/100 around 10 years ago, the first additional piece since the 80's. I remembered the hyperbole back then about them when someone brought it up on a forum thread. Hmm I thought:scratch2:, I think I'm gonna get me one of those. So in the course of hunting one down(I suppose it is a hunt once my interest is aroused), I came across lots of opinions and specs confirming I want it. I've since bought and sold a 25/25, 150MKII, and a 250/250. I still have the 100/100, the best by far. A bit sluggish sounding but very musical. It actually has a holographic sound stage. Gimme Shelter is spooky with it. Happened the same way with everything else. Simple, eh? Mind you without the net, aka this forum and others, it wouldn't have happened at all.

Thank you.

whoaru99 asked about considering "consumer feedback as a spec, of sorts". If we are talking about the Amazon style feedback, then my answer is no. I do not know anything about the folks who leave those reviews. Are they experienced listeners? Do they have the same listening biases as I do? Who knows?

Regarding research. As you stated, the Internet provides a wealth of information on new companies, products, etc. If I see something interesting that fills a hole in my equipment menagerie, I figure out how to go about arranging an audition. As I get to know the wonderful people on AK better, I may find some who have similar listening biases to mine.

I am also fortunate to have access to a group of folks who get together regularly to listen to new components, talk about music, etc. which expands my access to interesting components.

Specs? I don't look at them anymore because I want to listen to the component for an extended period of time in my room.

Until I took delivery of my Lowther PM2a/Medallion speakers, I had never heard a pair of Lowthers in my life. I wanted to experience analog amplified via a SET amp (no phase splitter) into a full range driver (no crossover). I was rewarded with one of the most involving and musically satisfying sounds I have ever lived with. I am taking a break and playing with my JBL's and Klipsch but the Lowthers are not for sale.

Had it not worked out? Well....I would have sold that combo and tried something else.

And the addiction rolls on.....

 

[Superampman]

Thank you.

whoaru99 asked about considering "consumer feedback as a spec, of sorts". If we are talking about the Amazon style feedback, then my answer is no. I do not know anything about the folks who leave those reviews. Are they experienced listeners? Do they have the same listening biases as I do? Who knows?

Regarding research. As you stated, the Internet provides a wealth of information on new companies, products, etc. If I see something interesting that fills a hole in my equipment menagerie, I figure out how to go about arranging an audition. As I get to know the wonderful people on AK better, I may find some who have similar listening biases to mine.

I am also fortunate to have access to a group of folks who get together regularly to listen to new components, talk about music, etc. which expands my access to interesting components.

Specs? I don't look at them anymore because I want to listen to the component for an extended period of time in my room.

Until I took delivery of my Lowther PM2a/Medallion speakers, I had never heard a pair of Lowthers in my life. I wanted to experience analog amplified via a SET amp (no phase splitter) into a full range driver (no crossover). I was rewarded with one of the most involving and musically satisfying sounds I have ever lived with. I am taking a break and playing with my JBL's and Klipsch but the Lowthers are not for sale.

Had it not worked out? Well....I would have sold that combo and tried something else.

And the addiction rolls on.....

For me, specs are very important. I understand that there is always a correlation between good performance and good sound. I would not believe a report that an amp was great sounding but had poor specs. I would not bother going out of my way to verify this. I understand great specs don't necessarily affirm great sound. But you simply cannot have good sq with lousy specs, period. Specs weed out bs.

 

[restorer-john]

It's an interesting way of looking at the hobby, looking for that 'musically satisfying sound' and ignoring, or not looking at the technical side of the gear (the specs).

I'm not sure I could do it. My guess is that ultimately, you'd get so far away from accurate amplification and speakers and into the area of straight up euphonics that you could never return- a kind of slippery slope, without a reference point of known accuracy (measured parameters).

It'd be fun though, an audio equivalent of a pub-crawl where every pub and every drink gets you more confused and less able to discern what you are drinking and where you are, all the while having a great time, but ultimately passing out and waking up confused and with a headache.

For me, I have to have fully test an amplifier to determine what it does to a signal before it goes into my system. Then I see how it behaves and whether it stays for a while or not.

Great to see another perspective.

Cheers, I'm gonna have a drink.

Specs? I don't look at them anymore because I want to listen to the component for an extended period of time in my room.

Until I took delivery of my Lowther PM2a/Medallion speakers, I had never heard a pair of Lowthers in my life. I wanted to experience analog amplified via a SET amp (no phase splitter) into a full range driver (no crossover). I was rewarded with one of the most involving and musically satisfying sounds I have ever lived with. I am taking a break and playing with my JBL's and Klipsch but the Lowthers are not for sale.

 

[TubeHiFiNut]

For me, specs are very important. I understand that there is always a correlation between good performance and good sound. I would not believe a report that an amp was great sounding but had poor specs. I would not bother going out of my way to verify this. I understand great specs don't necessarily affirm great sound. But you simply cannot have good sq with lousy specs, period. Specs weed out bs.

That's fine. I have no problem with anyone using specs as a selection criteria.

I just no longer go to the spec sheet before listening and making my decision from there. SET amps taught me that lesson - elevated (mostly) 2d order THD.....Still sounds wonderful.

Snell Type A are the next pair of speakers I will probably bring into the man-cave.

Way back in the 70's, there was a lot of discussion around fidelity in the frequency domain versus the time domain.

If I remember correctly, the Type A has commendably flat frequency response but mediocre pulse response. Some reviewers panned them as a result.

Been listening to them at an old friend's house recently and they sound pretty darn good to me.

Time to do some trading.....their pulse response notwithstanding.

 

[TubeHiFiNut]

It's an interesting way of looking at the hobby, looking for that 'musically satisfying sound' and ignoring, or not looking at the technical side of the gear (the specs).

I'm not sure I could do it. My guess is that ultimately, you'd get so far away from accurate amplification and speakers and into the area of straight up euphonics that you could never return- a kind of slippery slope, without a reference point of known accuracy (measured parameters).

It'd be fun though, an audio equivalent of a pub-crawl where every pub and every drink gets you more confused and less able to discern what you are drinking and where you are, all the while having a great time, but ultimately passing out and waking up confused and with a headache.

For me, I have to have fully test an amplifier to determine what it does to a signal before it goes into my system. Then I see how it behaves and whether it stays for a while or not.

Great to see another perspective.

Cheers, I'm gonna have a drink.

Each to his own.

I listen with my ears and believe that music should touch your soul.....and I do not think that my systems are any less valid or accurate than yours.

I am happy that you have a process that works for you. This is what works for me and provides me with the most satisfaction.

YMMV.....

 

[Superampman]

Well, interestingly enough, when I selected my Meridian 105 monos in '78, it was a time domain induced decision. A first gen NAD 90wpch, zero headroom receiver burned up my brand new pair of B&W DM7s. Steep learning curve ensued when I took it back within that month and traded it for the 105s. Three times the cost. $2100.00 vs 700 for the NAD. He goes 'yea, but the Meridians are high end amps'. So he demos them on a pair of B&W 802s and I go 'What?' 'Listen to the cymbals', 'listen how tight/fast the bottom end is', 'bass definition', 'listen to the snare', 'listen to the vocal transients'. I was hooked.

 

[restorer-john]

That's very interesting to me as I have been spending a lot of time lately studying and reading about the theories of what we actually hear.
It seems we interpret wave shapes, not frequencies per se.

You are dead right about how certain amplifiers were panned in the 70s, and for good reason (at the time they thought), but have been subsequently seen as conceptually good, just poorly implemented. Some have stood the test of time very well, others have not.

I would love to hear your full range/SET combo, just to see if it presses the emotional buttons for me too.

Sadly, I think my foray into tubes (valves) was too little too late- I was too used to the sheer power and control of big SS amps, although the silky liquid nature of the few amps I played with was seductive all right. I was set in my ways I guess.

I put a few tube amps on a Cro and various frequency square waves only to turn them off in disgust. That preconceived knowledge on their technical merit, skewed my subjective listening.

I applaud your method, I do. I wish sometimes I didn't have a small lab full of test gear- it'd be easier to just 'listen'.

John

Way back in the 70's, there was a lot of discussion around fidelity in the frequency domain versus the time domain.

If I remember correctly, the Type A has commendably flat frequency response but mediocre pulse response. Some reviewers panned them as a result.

Been listening to them at an old friend's house recently and they sound pretty darn good to me.

 

[restorer-john]

The number is an unusual designation for a UK brand so I looked this up on wikipedia:

The meridian 105° west of Greenwich is a line of longitude that extends from the North Pole across the Arctic Ocean, North America, the Pacific Ocean, the Southern Ocean, and Antarctica to the South Pole.

The 105th meridian west forms a great circle with the 75th meridian east.

The west as the reference meridian for the seventh time zone west of Greenwich, known as UTC-07 or the Mountain Time Zone in North America.

In the United States, Interstate Highway I-25 roughly parallels the meridian from Douglas, Wyoming to Las Vegas, New Mexico, and from Wellington, Colorado to the Prospect Road interchange (in Fort Collins, Colorado), I-25 happens to be almost exactly aligned along the 105th meridian west. The meridian bisects Denver, Colorado, passing through Denver Union Station. Throughout the Denver metro area, Kalamath Street is the road that most closely corresponds to the 105th meridian.

then there's these guys:

http://www.meridian105.com/projects.html

their architecture resembles this:

Well, interestingly enough, when I selected my Meridian 105 monos in '78, it was a time domain induced decision. A first gen NAD 90wpch, zero headroom receiver burned up my brand new pair of B&W DM7s. Steep learning curve ensued when I took it back within that month and traded it for the 105s. Three times the cost. $2100.00 vs 700 for the NAD. He goes 'yea, but the Meridians are high end amps'. So he demos them on a pair of B&W 802s and I go 'What?' 'Listen to the cymbals', 'listen how tight/fast the bottom end is', 'bass definition', 'listen to the snare', 'listen to the vocal transients'. I was hooked.

 

[JoeESP9]

Were those the nearest stereo shops to you, or just the nearest ones that carried the item you wanted to hear?

It's only a few miles short of twice as far to the nearest stereo shop I know of from me as the Philly to DC trip you made. Of course I can't talk since it's been years since I've been to Louisiana where I've only recently heard they still have a real stereo shop.

Those of us who live in the Delaware Valley area (PA, NJ, DE) are blessed to have quite a few brick and mortar stores that carry a wide variety of mid-fi and high end gear. We even have a store that handles a lot of used gear (TSTO).

My trips to NYC and the DC area were because no one local had specific items.

It just seems incongruous to me that so many move to the "burbs" to get away from everything and then they berate the lack of merchandisers close to them.

 

[eickmewg]

I have four amplifiers, two tube (Latino VTA ST-120 and Yaqin MS-30L) and two SS (Halfer DH-200 and Forte 55). I find that the tube amplifiers sound a little different from the solid state amplifiers with richer mid range but less bass authority. However, the two tube amplifiers sound very similar to one another and the two solid state amplifiers are also very similar to each other. The net result, however, is that all four sound pretty much the same to my ears. That said, I generally have one of the tube amps running in my system as I like the warm glow of those tubes!

 

[Superampman]

The number is an unusual designation for a UK brand so I looked this up on wikipedia:

The meridian 105° west of Greenwich is a line of longitude that extends from the North Pole across the Arctic Ocean, North America, the Pacific Ocean, the Southern Ocean, and Antarctica to the South Pole.

The 105th meridian west forms a great circle with the 75th meridian east.

The west as the reference meridian for the seventh time zone west of Greenwich, known as UTC-07 or the Mountain Time Zone in North America.

In the United States, Interstate Highway I-25 roughly parallels the meridian from Douglas, Wyoming to Las Vegas, New Mexico, and from Wellington, Colorado to the Prospect Road interchange (in Fort Collins, Colorado), I-25 happens to be almost exactly aligned along the 105th meridian west. The meridian bisects Denver, Colorado, passing through Denver Union Station. Throughout the Denver metro area, Kalamath Street is the road that most closely corresponds to the 105th meridian.

then there's these guys:

http://www.meridian105.com/projects.html

their architecture resembles this:

Beauty is the ear of them's beholder.