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Is there a noticeably audible difference between two level matched solid state amps under controlled

  • Yes... I believe a notable difference can be heard.

    Votes: 136 48.6%
  • No... I do not believe there is any audibly significant difference.

    Votes: 144 51.4%

  • Total voters
    280
801 - 820 of 833 Posts

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Yep,
I think I understand in essence what is happening. This is not a judgement ..., but whats happening (i think i can see) I'm just stirring the pot one more time and what'ta you know "nothing new here"
I wonder if a statistician would ever take on this task he/she would need to have a high appreciation of music and sound reproduction.

Another concern/issue I think I see is "the industry" is moving too fast. I mean how much time do you get to spend with comparing the same any two amps. One weekend and its on to the next shinny and newest iteration. The basic electronics "Pre to Power" haven't changed much except the sound gets processed differently from 10trs ago.

If I ever come up with a survey questionnaire I'll post as a new post open to discussion and critique...

Just Thinkin':An old friend has a pair of 50's vintage "Altec Lansing Voice Of The Theater" speakers and at least 20 to 50 Pre/Power amps to choose from, both new and vintage, but the sound.... The sound you feel is cavernous while filling a 20x20' room and is awe inspiring. You can actually see many notes traveling across the cone excursions.

Happy Listening and Best Regards
Greg
 

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I love this video - I find no difficulty accepting Mr. Krueger' descriptions of electronic phenomena in minutia and even as he describes the minds ability to steer itself to into convincing oneself of what was intended/expected to hear. Only a few times did I get the sense Mr Krueger forgets that even his descriptions lean toward subjective bias. Do not misunderstand me I find this info truly inspired and each point valid in each seperate domain(subjective audio register). I simply enjoy music when I hear what I expect and/or want to hear "that's the best for me" - my room treatments are the coat rack, furniture and clutter except for the louvered room divider that in effect squares the room. I work with toe in and speaker distances along with Audyssey leveling. One day I may apply baffling to the front wall but I'm liking the sound-stage I hear and I'm afraid I'll then want bigger speakers. Blah, Blah, Blah Just consider all the sound reflections even at Carnegie Hall or the Orpheum Theater. I remember the Kooper, Bloomfield "Supper Session" at the Boston Gardens in the 60's (it doubled as an ice arena) like a theater in the round the music was everywhere but the volume and music at center stage blew me away. I don't believe I would like a dead quiet room LOL - but if I can quiet my mind from all of the useless chatter and truly hear what is in front of me..., who knows???? As usual I could be persuaded to change my mind.

Happy listening and Best Regards
Greg
 

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Dogs will love ya and treat you like your the greatest every time you walk into the room and you do have a point to coonsider.

I love it....
Greg
 

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The dogs do love Blue Lou, yep indeed.
I think Leonard has it right in that we will never reach a consensus in out opinions and I really dont want to try to influence anyone. Anything I type seems to come back as me trying to put a blanket of my beliefs onto someone else...and....others opinions oft times feel like a blanket of beliefs on me. This has to be so much easier when we come to accept that maybe we can both be right. I have mine and will live by them and the other fine group of gents seem to be happy as well. So what the , lets listen in a way that makes us happy and maybe raise a bit of goose bumps on our collective skins.
I would even cheer for a tear or two. Yeah baby !!!
 

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The dogs do love Blue Lou, yep indeed. I think Leonard has it right in that we will never reach a consensus in out opinions and I really dont want to try to influence anyone. Anything I type seems to come back as me trying to put a blanket of my beliefs onto someone else...and....others opinions oft times feel like a blanket of beliefs on me. This has to be so much easier when we come to accept that maybe we can both be right. I have mine and will live by them and the other fine group of gents seem to be happy as well. So what the , lets listen in a way that makes us happy and maybe raise a bit of goose bumps on our collective skins. I would even cheer for a tear or two. Yeah baby !!!
Well said.
 

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In the process of completing a recent speaker review, I had an interesting experience relating to this discussion. There were three amps used to drive the speakers in question - 94 dB efficient, so they did not need huge amounts of power to play at a decent volume. There was a 15 w / channel solid state amp, a pair 300 W / channel differential class-A solid state monoblocks, and a pair of 8 W / channel SET tube amps. A few observations:
  • I never heard hard clipping from the 15 W / channel solid state amp, but there was a point beyond which I wanted to hold back on the volume, and a sense of strain or tension if pushing the volume further. Presumably, the ear starts to hear an occasional small "clip" or the mere onset of clipping and reports it as that "tension" in the sound. While driven "clean," there was nothing distinctive about their sound.
  • The 300 W / channel monoblocks had such energy reserves that they felt like you could bring down the house and never hear distortion. A point for "can't hear a difference...???" Maybe, but there was an emphasis in the mid-bass that was totally unexpected and easy to identify. I mentioned it to my host and he said he had noticed it, had taken measurements, and the measurements showed no difference from other solid state amps. With no measurements of my own and no further data, all I can say is there was something about amp/speaker interaction that was audible and it was definitely NOT distortion. So, where in this discussion does that one fit?
  • The 8 W / channel SET tube amp had what I can only describe as a softened attack on the bass, again clearly audible. This can be explained by the higher source impedance of the tube amp and the lower damping factor, affecting the degree of control the amp has on driver movement, mainly the woofer. So this might be a data point for the side saying an amp can sound different because of a different design, another case of amp/speaker interaction causing a different sound. This could probably be shown with careful measurements of the right type. These amps were not pushed hard at all, so it was not a distortion / nonlinearity issue.
So, three amps, three different sounds. The small solid state amp with its clean sound when not driven to the beginnings of distortion, the big monoblocks with an apparent boost of mid-bass - unexplained, and the tube amps with no apparent mid bass boost but with softened bass attack due to lower damping factor. All this was totally unexpected to me. I was not looking for or expecting to hear any difference at all or even thinking about it, they just jumped out at me quite obviously and were confirmed by other listeners.
 

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Excellent post Craver, I am glad you tried a nice group of amps that could not be more different from one another. SS and Tube amplifiers work differently when connected to a loudspeaker in that SS tends to drive the speaker and accepts no feedback while a tube amp tends to drive the loudspeaker but does accept some feedback thus allowing the amp and speaker to sort of speak to each other.

I dont think one is better than the other when it comes to most situations, however the low power set will not work well with most speakers not intended to be driven by the flea watt brothers. I have a 30 wpc tube amp that does not really sound all that "Tubey" if you will but even at 30 wpc, it has limitations.

Lastly, I wonder if there will ever be a definitive answer as to the proper amount of damping factor needed to control a loudspeaker. Most experts seem to say anything above 20 is good and should work fine. Crown seems to say 1000 might be really good and the class D amps tend to all have some serious damping factor but have not thus far been well received. This is a great post up.
 

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(A little thread necro to the thread that brought me here, in the market for some new separates to drive my Martin Logans.)

Hello everyone, :wave:

I found this thread pretty amazing and eye-opening. I found myself wishing the "no difference between amps" camp had a resource like the following:

- A list of "good enough" amps that fit the criteria of this thread. :eek:lddude: Rather than sites with hyperbolic effusive descriptions of amp sound -- a thumbs up/down for given speaker drive should be sufficient.
- And/or a guide on how to do "good enough" testing on a given amp so someone else could carry the above mantle.

I don't have the EE background it appears many in this thread have so I was lost a few times when people were checking amps with voltage meters for given impedance, etc. I have "hard to drive" speakers and would like to be sure I get an amp that can drive them with great imaging and lots of air. :huh:

FWIW, I have always heard differences between amps -- but almost all of those impressions were from integrated amps or amps on low-end pre-amps... so it makes sense to me that the big difference would be in the pre rather than the amp proper.

Thanks in advance to anyone who could point me to a resource like I mention in the above.
For the curious I'm currently considering...

Krell Foundation pre-amp
Pass Labs amp for the fronts (MartinLogan Ascents). Hopefully would be better than my old dead sonographe? I did love that (cheap) amp.
No real thoughts for rear amp yet.
 

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In the process of completing a recent speaker review, I had an interesting experience relating to this discussion. There were three amps used to drive the speakers in question - 94 dB efficient, so they did not need huge amounts of power to play at a decent volume. There was a 15 w / channel solid state amp, a pair 300 W / channel differential class-A solid state monoblocks, and a pair of 8 W / channel SET tube amps. A few observations:
  • I never heard hard clipping from the 15 W / channel solid state amp, but there was a point beyond which I wanted to hold back on the volume, and a sense of strain or tension if pushing the volume further. Presumably, the ear starts to hear an occasional small "clip" or the mere onset of clipping and reports it as that "tension" in the sound. While driven "clean," there was nothing distinctive about their sound.
  • The 300 W / channel monoblocks had such energy reserves that they felt like you could bring down the house and never hear distortion. A point for "can't hear a difference...???" Maybe, but there was an emphasis in the mid-bass that was totally unexpected and easy to identify. I mentioned it to my host and he said he had noticed it, had taken measurements, and the measurements showed no difference from other solid state amps. With no measurements of my own and no further data, all I can say is there was something about amp/speaker interaction that was audible and it was definitely NOT distortion. So, where in this discussion does that one fit?
  • The 8 W / channel SET tube amp had what I can only describe as a softened attack on the bass, again clearly audible. This can be explained by the higher source impedance of the tube amp and the lower damping factor, affecting the degree of control the amp has on driver movement, mainly the woofer. So this might be a data point for the side saying an amp can sound different because of a different design, another case of amp/speaker interaction causing a different sound. This could probably be shown with careful measurements of the right type. These amps were not pushed hard at all, so it was not a distortion / nonlinearity issue.
So, three amps, three different sounds. The small solid state amp with its clean sound when not driven to the beginnings of distortion, the big monoblocks with an apparent boost of mid-bass - unexplained, and the tube amps with no apparent mid bass boost but with softened bass attack due to lower damping factor. All this was totally unexpected to me. I was not looking for or expecting to hear any difference at all or even thinking about it, they just jumped out at me quite obviously and were confirmed by other listeners.
Hi Audiocraver,
your posts are always interesting :)

Do you have the opportunity to connect an oscilloscope during the playback with actual music material with a wide dynamic range and a real loudspeaker load?
I think that much more often then expected the amplifier may be clipping but for such short periods of time (milliseconds during the peaks) that the listener cannot recognize that as clipping... but the sound quality would nonetheless be different for trained listeners, what is your thought?

(may be there is truth in both camps 'cause in the real world we don't listen under controlled conditions and if we did we may have surprises from the behaviour of our amps...)

Thanks, Flavio
 

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The HTS brain trust did an excellent amplifier evaluation get together.
The iPad is not letting me capture the link to the thread but a search for...

Home Theater Shack 2015 High-End Amplifier Evaluation Event Reporting and Discussion Thread

Should find the discussion thread.

There was a lot of effort put into that evaluation and report, it is a good read.
 

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Here is the link Chase referred to: 2015 Amp Eval -

http://www.hometheatershack.com/forums/home-theater-receivers-processors-amps/115674-home-theater-shack-2015-high-end-amplifier-evaluation-event-reporting-discussion-thread.html

..., but first there are a few considerations to keep in mind as you search HTS. One is, although most HTS members admittedly have dedicated two channel audio setups in their "Home Theater (HT)" much of what I've read here @ HTS is about "HT" multi-channel listening. That does not mean the information and equipment testing, reviews, opinions presented herein can be or should be overlooked.

Second, much of the testing and reviews deal with the newest and best multi channel AVR's, Pre/Pros, DAC's, Amps and Video equipment.

Third, HTS is not a Hi-end Boutique "cost is no object" forum.

That said - if you want to learn about the newest and best electronic A/V technology available in the market and how to setup a theater or two channel system that will give you goose-bumps every time you hit the power button..., keep reading, your getting close.

I am not saying your headed in the wrong direction with Krell and Pass Labs. I keep thinking a Krell Showcase is in my future or just start with the Krell Vanguard. I should..., before my hearing losses are noticeable to even me.

I'll just add - if your looking at the Pass Amp because (as advertised) it will handle "low impedance loads" and you believe your ML electrostatics are difficult to drive for that reason..., stick around. There are and have been HTS members playing even music thru ML Electrostatics powered with Emotiva seperates and integrated elec's and I believe even Denon AVR's and the like all without issue given ample wattage.

My simple observations are (some experience) most of the High Current including digital amplification Audio electronics in the 125-200watt range will reproduce a very satisfying reference level sound that will keep you on the edge of your seat or in the dream state - whichever you prefer.

All that said - I'm thinking about the Krell Showcase even more seriously now.
 

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(A little thread necro to the thread that brought me here, in the market for some new separates to drive my Martin Logans.)

Hello everyone, :wave:

I found this thread pretty amazing and eye-opening. I found myself wishing the "no difference between amps" camp had a resource like the following:

- A list of "good enough" amps that fit the criteria of this thread. :eek:lddude: Rather than sites with hyperbolic effusive descriptions of amp sound -- a thumbs up/down for given speaker drive should be sufficient.
- And/or a guide on how to do "good enough" testing on a given amp so someone else could carry the above mantle.

I don't have the EE background it appears many in this thread have so I was lost a few times when people were checking amps with voltage meters for given impedance, etc. I have "hard to drive" speakers and would like to be sure I get an amp that can drive them with great imaging and lots of air. :huh:

FWIW, I have always heard differences between amps -- but almost all of those impressions were from integrated amps or amps on low-end pre-amps... so it makes sense to me that the big difference would be in the pre rather than the amp proper.

Thanks in advance to anyone who could point me to a resource like I mention in the above.
For the curious I'm currently considering...

Krell Foundation pre-amp
Pass Labs amp for the fronts (MartinLogan Ascents). Hopefully would be better than my old dead sonographe? I did love that (cheap) amp.
No real thoughts for rear amp yet.
Your suggestion has merit. Finding
  • A torch bearer to compile the information you suggest
  • Agreement on the results
is the tricky part.

Sonnie Parker owns a pair of ML Electro-Motion ESL, their entry-level hybrid electrostatic model. He drives them with 2 channels of a Parasound Halo A31. I have listened to them at near blistering volumes and the combination sounds amazing.
 

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Gregr:

Love your signature line:

"We believe everything we tell ourselves..., don't we??"

My answer (FWIW): Yes, until we start to question what we have been believing... "Do I really believe that? Am I really hearing that?"
Exactly - I used to say we stumble upon our best lessons in life..., then proceed after achieving a reasonable sense of equilibrium. In effect, convincing ourselves of our unique intellectual/expert (expert in the sense of our unique experience/not all-knowing) nature. Otherwise, personal schema breaks down and neurosis sets in..., or worse. Maybe a good reason why we defend our positions so adamantly - like life depended on it for some...
I like a bumper sticker I saw once "question authority" and I sort of re-purposed it for my benefit, "Question Reality" then I stumbled upon the question: We believe everything we tell ourselves... .

You know, as do I, electricity can be defined mathematically - but what is the energy that fills the void between and creates the 3D construct of pos/neg, where does that energy come from..., its just there and we define it from the position of observable phenomena, right? Science is still discovering dimensions of lightning that redefines the way science views the world e.g. sprites and ionic expansion etc. What of quantum science and the prediction of higher and lower in-phase, energy levels or dimensions existing within our reality/dimension..., no longer a hypothesis this is a working theorem in the quantum world.

I don't claim to have a golden ear and at 65yrs after listening to loud music most of my conscious life I've probably given up the opp to develop an educated ear, so I'm on the fence as to what the differences in sound in pre/pro/amp could be as described by others.

But try this simple experiment: take two lengths of speaker cable; one simple OFC lamp cord and another an MIT Shotgun or Kimber 8TC speaker cable (random selection). First, play music using your typical cables, then:

1. disconnect power source
2. disconnect a single speaker cable (disconnect from the amp first)
3. connect (the speaker end of the cable first) any purported "better cable" of equal length in place of
the removed cable.

..., and listen. I'll bet for the first few minutes your head will tilt sideways. However, in time, I'll bet somehow the cables sound more and more similar. Like when children are born cross-eyed and after corrective surgery may view the world upside-down in one or both eyes, but eventually (usually) the mind re-inverts to a more useful upright and uniform vision. Or, did the amp/pre/pro equalize in response to electro-stasis tension or... ?

I sense we listen to elec sound and video reproduction in hopes of suspending disbelief even for just a moment and hopefully longer. As far as the "can we hear..." question, I'm not sure what the answer is or if there is a definitive answer. I am sure if 12 people are listening to music in the same room at the same time you'll get 12 different descriptions of what they heard (except when each of the 12 are very familiar with the expectations of others in the group). Sometimes I wonder if the question is "can people be trained to listen and hear reproduced sound critically". But then the question is how? Free-divers can train their bodies for deep-dives but what considerations would you choose for adjusting/max psychophysiology, bio-physiology, belief structures/expectations, recency effect and other forms of bias etc etc...

I should write a book, but not here.

Sorry to go on like this...

Best Regards and Happy listening
 

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Well guys, I'm in the pro-audio since early 1990 and the only thing I have to say is that "there is a big difference" between amps and I will put an example from my personal experience : Back in 1999, I won a contract to upgrade an auditorium sound system that has an EV 2 way active system 4 tops+4 subs all with QSC MX 3000 & 4000 amplifiers. So before moving to a new speaker system , I switched all amplifiers and tested with Lab-Gruppen FP series and the sound changed absolutely , so big was the difference in sound quality that I did an A/B comparison test with the same system : L with the original QSC amps & R with the Lab Gruppen and that's it and the difference was immediately noticed.
This is my personal experience and there's a big difference between amps, at least in the pro-audio field.

Cheers.

Alan
 

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Its very possible looking at the specifications of the QSC MX 3000/4000 that they may have been loaded up to much. Without knowing what model of the Lab-Gruppen amps its hard to say. If the Lab-Gruppens were able to handle the load better without distortion that can be a big change in sound.
 

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Treading carefully, I have to admit that I have heard some differences as well. One pair of speakers that I reviewed a couple of years ago sounded markedly different depending on the amp in use. tube vs solid state, both amp pairs monoblocks. Damping factor interaction with speaker impedance might have been involved. Channel separation is rarely specified vs freq any more, and that is another area which could affect imaging at HF, causing a perceptible difference in "sound."
 

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I agree, I recently had to pull my Samson Servo 600 out to get fixed (one flakey channel) and used my QSC MX1500 for a few weeks and the sound was very warm compared to the Samson. The highs were more laid back (actually did not like it) and was glad to get the Samson back in. The QSC is 4 times the power output so I had to run the gains really low at about 20% so not sure if that had any impact on the sound.
 
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