The AHB2 is designed with THX technology.
Reviewed here:
https://www.audiosciencereview.com/...-and-measurements-of-benchmark-ahb2-amp.7628/
- Rich
-
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Amplifiers can you hear a diffrence?
- Thread starter Pjetrof
- Start date
The AHB2 is designed with THX technology.
Reviewed here:
https://www.audiosciencereview.com/...-and-measurements-of-benchmark-ahb2-amp.7628/
- Rich
Dimitri
Senior Member
Predistortion was talked about around 2004 ... what they call "radical" and new is not all that "radical"... or "new" in the large scheme of things.
http://highfreqelec.summittechmedia.com/Apr04/HFE0404_Stapleton.pdf
http://highfreqelec.summittechmedia.com/Apr04/HFE0404_Stapleton.pdf
I listened to two Devialet models, the Le 250 and its upgrade the 250 Pro, one after the other. This was done at a dealer. It was a blind test as they are visually identical and even if you could see the small display window from the seating position, which I couldn't, the model number is only displayed when the unit is switched off. The dealer changed the speaker connections and usb source and I could not see as the units were stacked one on top of each other. Switch-over took less than a minute. They certainly did not sound the same and I bought the one that I thought sounded better.
Is this not cognitive dissonance at is finest ? Done that myself before my audiophile card expired.
* it is very unlikely to hear any difference between properly working amplifiers ( not practically impossible as in DAC’s) there are very good scientific reasons for this inaudible levels of distortion and very low noise levels.
* you do an “experiment” in other words a casual listening session .....
And hear a difference ! Not just, “this amp hiss a little more” but 3D soundstage tonal balance pace rhythm melody and musicality .
The logical conclusion can bee either .
Guess’s all this science is wrong , my personal experience is more valid .
Or
There is something wrong with the “experiment”
.
Personally I think after decades of being an audiophile and then recovering there is almost always something wrong with the “experiment” .
So most of the listening sessions tests an casual listening done at friends dealers etc the things that forms your whole experience and expectations of how audio equipment performs are not really done correctly ? But still they bias your expectations.
I would argue that for listening test in order of preference I would use “trained listeners” , “random dude picked up at the buss stop” , “ other “ .............. “audiophiles”
* it is very unlikely to hear any difference between properly working amplifiers ( not practically impossible as in DAC’s) there are very good scientific reasons for this inaudible levels of distortion and very low noise levels.
* you do an “experiment” in other words a casual listening session .....
And hear a difference ! Not just, “this amp hiss a little more” but 3D soundstage tonal balance pace rhythm melody and musicality .
The logical conclusion can bee either .
Guess’s all this science is wrong , my personal experience is more valid .
Or
There is something wrong with the “experiment”
.Personally I think after decades of being an audiophile and then recovering there is almost always something wrong with the “experiment” .
So most of the listening sessions tests an casual listening done at friends dealers etc the things that forms your whole experience and expectations of how audio equipment performs are not really done correctly ? But still they bias your expectations.
I would argue that for listening test in order of preference I would use “trained listeners” , “random dude picked up at the buss stop” , “ other “ .............. “audiophiles”
Is this not cognitive dissonance at is finest ? Done that myself before my audiophile card expired.
* it is very unlikely to hear any difference between properly working amplifiers ( not practically impossible as in DAC’s) there are very good scientific reasons for this inaudible levels of distortion and very low noise levels.
* you do an “experiment” in other words a casual listening session .....
And hear a difference ! Not just, “this amp hiss a little more” but 3D soundstage tonal balance pace rhythm melody and musicality .
The logical conclusion can bee either .
Guess’s all this science is wrong , my personal experience is more valid .
Or
There is something wrong with the “experiment”
Personally I think after decades of being an audiophile and then recovering there is almost always something wrong with the “experiment” .
So most of the listening sessions tests an casual listening done at friends dealers etc the things that forms your whole experience and expectations of how audio equipment performs are not really done correctly ? But still they bias your expectations.
I would argue that for listening test in order of preference I would use “trained listeners” , “random dude picked up at the buss stop” , “ other “ .............. “audiophiles”
In an amplifier test there are two main contenders for how things can go wrong .
One of DUT’s can’t rely drive the speakers even if you thought so.
The usual biases placebos etc .
The audiophile mind can make it even worse , one DUT can’t really drive the speakers and you pick the expensive fragile 25w class A amp anyway , you will ofcourse upgrade after another year .....
Is this not cognitive dissonance at is finest ? Done that myself before my audiophile card expired.
* it is very unlikely to hear any difference between properly working amplifiers ( not practically impossible as in DAC’s) there are very good scientific reasons for this inaudible levels of distortion and very low noise levels.
* you do an “experiment” in other words a casual listening session .....
And hear a difference ! Not just, “this amp hiss a little more” but 3D soundstage tonal balance pace rhythm melody and musicality .
The logical conclusion can bee either .
Guess’s all this science is wrong , my personal experience is more valid .
Or
There is something wrong with the “experiment”
Personally I think after decades of being an audiophile and then recovering there is almost always something wrong with the “experiment” .
So most of the listening sessions tests an casual listening done at friends dealers etc the things that forms your whole experience and expectations of how audio equipment performs are not really done correctly ? But still they bias your expectations.
I would argue that for listening test in order of preference I would use “trained listeners” , “random dude picked up at the buss stop” , “ other “ .............. “audiophiles”
Dealer demo. That says it all, it's like going to a magic show.
phoenixdogfan
Major Contributor
You can tell that if the tester uses the "power cube" which show wattage vs impedance vs phase angle on the X, Y, and Z axes. Peter Aczel utilized this measure in the latter days of "The Audio Critic". It's the one thing Amir doesn't do that I wish he did.
Those are 2 different things. THX patented AAA which is IIRC forward feed technique to eliminitate distortion while what I posted are parameters being tested to gain THX Ultra certificate.
In other words, using THX AAA doesn't automatically make an amp THX Ultra certified, although I would expect Benchmark AHB2 to pass THHX Ultra compliance test with flying colours.
Last edited:
It's very good the power cube , but prohibitively expensive it's discussed elsewhere. I think there was talk about building better load in some tread.
Or we could donate a shedload of cash for a power cube.
It's used by one of the audio rags in sweden and it's very telling on some amps
I had a quite different experience, but on different models.
My first Devialet was a D-Premier (before the configurator was on line and v3.6 firmware iirc) as soon as they updated the firmware to allow 2 bridged units I bought a second for more power, I was told it would sounded better but I didn't notice anything other than more power.
When I had mine updated totwo 250s I had them done one at a time, so I didn't have to go without a Devialet in my main system. When the 250 came back I compared it to the D-Premier and heard no difference and was actuallu irritated by the loss of the hdmi input which I had used for tv sound and the main gain of the 250 was more DSP to allow SAM, which I can't use since my speakers haven't been SAMed.
The 250 had a more robust power supply which is good, but a noisier analogue input which meant my previously silent MC phono input got audible hiss which was very bad but I just went back to its matching step up transformer and the MM input so back to quiet again so a bigger problem for others than myself.
Later I exchanged my 800, as two 250s become, for an Original d'Atelier because I like the colour.
My guess is that they raised the volume level of one of them a tiny amount to make it sound better, a standard marketing ploy.
I don't hear the huge difference between speaker cables my dealer assures me is there either but I do between my 4 record players.
OP
Pjetrof
Active Member
- Thread Starter
- #53
Thx to everyone for the replies.
But now 52 answers even a quote from mr. John Siau from Benchmark, speaking about diffrence between two amplifiers,
one his own the other an Accuphase amplifier. I suppose 2 very capable companies, if I understood correctly, in his quote
mr. John Siau explain why there is a difference in sound between those amplifiers. Does that mean that even mr. John Siau is wrong? Because at ASR the tone is, no audible difference between amplifiers. Everybody by now knows not clipping etc etc, normal use in home, using for example 20 watts, and al the amplifiers used don’t clip before 100 watts.
So there is no audible difference in using 100 different amps who don’t clip before 100 watt, from cheap to expensive from hifi to pa amps?
But now 52 answers even a quote from mr. John Siau from Benchmark, speaking about diffrence between two amplifiers,
one his own the other an Accuphase amplifier. I suppose 2 very capable companies, if I understood correctly, in his quote
mr. John Siau explain why there is a difference in sound between those amplifiers. Does that mean that even mr. John Siau is wrong? Because at ASR the tone is, no audible difference between amplifiers. Everybody by now knows not clipping etc etc, normal use in home, using for example 20 watts, and al the amplifiers used don’t clip before 100 watts.
So there is no audible difference in using 100 different amps who don’t clip before 100 watt, from cheap to expensive from hifi to pa amps?
John Siau explained where there is a difference in electrical terms. He never stated that difference would result in audible difference when listening 2 amps via the same speakers in the same room.
Is this not cognitive dissonance at is finest ? Done that myself before my audiophile card expired.
* it is very unlikely to hear any difference between properly working amplifiers ( not practically impossible as in DAC’s) there are very good scientific reasons for this inaudible levels of distortion and very low noise levels.
* you do an “experiment” in other words a casual listening session .....
And hear a difference ! Not just, “this amp hiss a little more” but 3D soundstage tonal balance pace rhythm melody and musicality .
The logical conclusion can bee either .
Guess’s all this science is wrong , my personal experience is more valid .
Or
There is something wrong with the “experiment”
Personally I think after decades of being an audiophile and then recovering there is almost always something wrong with the “experiment” .
So most of the listening sessions tests an casual listening done at friends dealers etc the things that forms your whole experience and expectations of how audio equipment performs are not really done correctly ? But still they bias your expectations.
I would argue that for listening test in order of preference I would use “trained listeners” , “random dude picked up at the buss stop” , “ other “ .............. “audiophiles”
My experience of dealer demo was for my amplifier, 4 years ago, was completely different.
It was not a casual listening session. I provided a set of sounds on a usb drive, which the dealer loaded on a server and provided me with an iPad. I listen to each sound for between about 15 and 45 seconds each. Each unit took about 20 to 25 minutes to go through the list. The dealer was not present. He was in his office. I had to go and get him to switch over the units, which were visually identical so I didn't know which one I was listening to.
Hiss? I haven't heard hiss from a solid state amplifier in my house for as long as I can remember, well over 10 years. Both units were dead quiet and the units I had at home were dead quiet. "Tonal balance pace rhythm melody and musicality" is complete b/s. Certain sounds, mainly involving hitting bits of wood together or striking metal were clearly different, sharper and better defined, others like solo violin I could not recollect a difference.
How would measurements help? Take one measurement, output impedance. One of these models, is stated at 0.001ohms. Stereophile measured another model from the range at 0.05ohms over 20-20khz. This compares to the AHB Benchmark amplifier that has higher output impedance of 0.09 to 0.22ohms over the same range. Does this make an audible difference? What other measurements would tell me that two pieces of wood being hit together will sound more realistic through amplifier A or B?
How do I deal with test measurements done over analogue inputs when I listen using an ethernet or wireless input? What is the relevance of a bit of inaudible measurable noise over the analogue inputs when they would only ever be used for a MM phono input?
That all sounds familiar! I've read that around versions 7 and 8 some of the software upgrades were more like downgrades. In late 2016 my listening comparison of Le 250 and 250 Pro were with the same older streaming card, so like for like, the 250 Pro now has the new streaming card. The version 13 firmware (February 2019) was quite transformative to performance generally.
I agree that the analogue input is fine for high output cartridges. Mine is 2.4mV. There is a bit of noise with a low output 0.2mV cartridge, but it did not disturb my listening for 3 years. Out of curiosity I recently purchased a good used external phono amplifier and I think it is slightly better than the internal one, but if there is a difference it is marginal. My phono amplifier of choice costs about twice the price of the Devialet Expert 140, so it is a bit unfair to compare a £10,000 standalone phono amp to a phono amplifier inside a £5,000 all-in-one music system.
I assume Stereophile reviewed and measured the Devialet 140 because Devialet wanted to promote that particular unit, as it is their first and only Expert model that have managed to squeeze under the €5,000 mark. Marketing issues seem to be irrelevant on ASR, even if successful (and I understand it has been successful), but the 140 has only one pair of RCA rather than two on our units and their performance may not be as good. A more basic phono amp was used and the pre-out facility removed. My suspicion is that they considered the Expert 140 to be a very good proposition at €5,000 excluding the amplifier and they did not want people buying the 140 and hooking it up to other more powerful amplifiers rather than buying a 220 or 250. This is somewhat ironic given ASR are only interested in considering the amplifier section of the Expert 140, and through the analogue input that no one would use for a digital source.
I only have one record player, but it does have two arms and one is a Jelco so I can switch cartridges easily.
My unit is in a cupboard so I don't look at it, which is a good thing given its ability to collect dust and fingerprints. It's lucky that's one of the things AMR don't have a measurement for (the Jiff index?).
I chose the D-Premier because it had the best phono input I had ever used. My previous phono stage was a Goldmund PH2, which I still have.
Anyway I only use a record player when the music I wish to listen to next is on an LP, otherwise CDs mainly.
I don't think the difference between D-Premier and more recent ones is anything but noise and the loading etc adjustments are way better than any other phono stage I know of.
Price is a poor arbiter of SQ IME in any case.
Blumlein 88
Grand Contributor
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Did you maintain the same volume setting at all times during each 20-25 minute session?
You do realize listening for 20+ minutes, plus time to go get dealer to swap, means your acuity to hear differences is dramatically reduced, very dramatically reduced. The chance your brain will falsely cue into to something upon second hearing is also dramatically increased this way. And even more so since you at all times knew when switching had occurred. Even if you didn't know which unit was playing.
Your comparison methodology as described is exceptionally poor. Any real differences would have to be comparatively huge for you to pick up on them. So the most likely result is an extremely high probability you'll hear a difference in the units when none existed. Not to mention possible influence in what was a single blind test in the manner of the Clever Hans problem.
Any difference you perceived that was real in this method would have been large enough to easily measure. The testimony about short sounds of striking wood or metal together sounding different is just the kind of transient with decay your mind goes crazy about creating differences where there were none. You are asking how measurements help assuming your perceived difference was real. It is tremendously more probable there were no audible differences. Finding measurements for what isn't there except as created in your mind is of course not going to happen.
Such methodology is inherently flawed and not worth the time it took for you to type about it or for me to respond. Other than to perhaps illustrate the issues. If you wish to test whether you hear some gear as different, your method isn't a way to successfully accomplish that.
You are asking the wrong question. Most people here seem to base decisions only on measurements. Measures well = good, doesn't measure well = bad. Underlying assumptions appear to be that (a) everything can be measured, and (b) measurements will tell you everything.
I don't think it's got anything to do with listening to the amplifier, or doing a blind comparison of two amplifiers.
Think of it this way. If I gave you the specifications of two pianists playing some music - the exact speed of each finger movement and the amount of force used by each finger, and the same with the pedals. Could you use that data to decide which performance you preferred?
Well it is certainly a fact that we can measure the performance of electronics to a much higher level than our auditory accuity. We can measure noise down to levels less than we can hear, we can measure frequencies over a broader range than our ears can detect and the dynamic range of measurement is close to the maximum dynamic range of the ear, though music gets nowhere near this limit anyway and our ears need a long time to rest after hearing loud noises before it can detect quiet ones.
The only thing few people measure in power amplifiers is their performance into difficult loudspeaker loads.
Your pianist analogy does not follow at all.
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