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Review and Measurements of Benchmark AHB2 Amp

maty

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"If." But he hasn't, so again, not a single example.

As I have already said, there is no measurement with respect to an amplifier that has to do with the depth in the reproduction, at least that I know. That is why I asked you to indicate some of the ABH2 measurements that indicated it, but you have been unable.

The depth not only has to do with the speakers, their placement and the room, it also affects the amplifier. Which amplifier measurements? I do not know.

That is why the usual audio measurements are a necessary but not sufficient condition. Good measurements of course.
 

SIY

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As I have already said, there is no measurement with respect to an amplifier that has to do with the depth in the reproduction, at least that I know. That is why I asked you to indicate some of the ABH2 measurements that indicated it, but you have been unable.

The depth not only has to do with the speakers, their placement and the room, it also affects the amplifier. Which amplifier measurements? I do not know.

That is why the usual audio measurements are a necessary but not sufficient condition. Good measurements off course.

You missed the point. Can you name ONE case where two amplifiers were compared, just ONE case, where "depth" and "timbre/tonailty" were found to be different, but frequency response and crosstalk (which are the measurements I suggested) were both satisfactory (i.e., flat frequency response and crosstalk better than, say, -50dB across the band)? Not anecdote, actual listening test. Ears only, no peeking.
 

RichB

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Wrong quote. Deleted.
 

maty

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About depth, Denon PMA-1600NE has good measurements. https://www.audiosciencereview.com/...mance-of-my-denon-pma-2500ne.7850/post-188992

The other day I read a comment about the sound: https://www.alpha-audio.nl/review/review-denon-pma-1600ne/6/

with Google Translate:

[ Detail

What we hear in both cases, however, is that the Denon has little color and a striking amount of detail. The fine structures of guitar work, copper and reverberation are fine by the Focals. With less chic speakers, that effect is of course a bit lost. But that speaks for itself.

What we miss is space in the display. The whole thing sticks to the speaker. It doesn't really go back, forward or sideways. At least: not as much as we had hoped.

This is not only the case with the Focals, but also with the Elacs and XTZ spirits. And both through the optical input that we use and the analog input that the Pavane is attached to. It must therefore be a characteristic of the Denon. We also noticed that with the more expensive PMA-2500NE. ]

Why? I suspect that has too much global negative feedback -> good/very good specs, but sound?
 

RichB

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You missed the point. Can you name ONE case where two amplifiers were compared, just ONE case, where "depth" and "timbre/tonailty" were found to be different, but frequency response and crosstalk (which are the measurements I suggested) were both satisfactory (i.e., flat frequency response and crosstalk better than, say, -50dB across the band)? Not anecdote, actual listening test. Ears only, no peeking.

I have heard hum coming from amplifier transformers when the ambient noise was at that level measured 47dB.
The noise measurement did not change when the amp was turned off. I am certain that I could detect it on an off.

-50 dB is not good enough.

- Rich
 

DonH56

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Actually this is incorrect. The supply does not produce the tracking rails. It only provides DC voltages. It is actually easier to do this with a linear supply. The main difference is that we can achieve a much better SNR with a switch-mode power supply due to the much weaker stray magnetic fields (which also happen to be at frequencies that are well above the audio band).

@DonH56, that was still a good guess! And we did discuss this in the design process. It would have been possible to generate tracking rails with a class-D amplifier, but we chose to keep the entire amplifier analog. We wanted to keep IMD and THD low and we wanted to avoid producing out-of-band noise.

My apologies, I must have had another amplifier in mind that adjusted rails using the SMPS (almost certainly a class-D amplifier, not class G).
 

RichB

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TUXAHB2Small.jpg


Clearly passing the low noise test.

- Rich
 

SIY

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-50 dB is not good enough.

Better than the best phono cartridge ever made. I don't know the literature, but in my own tests, I could detect no differences when it was as low as -30. Do you have a reference that suggests otherwise?
 

orangejello

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@orangejello

Seriously speaking, do you notice depth, 3-D sound in the two amplifiers? Is the timbre/tonality correct?

There are factors that can not be measured and you have to rely on ears used to appreciate good/very good recordings with acoustic instrumentation and high/very high DR.

Tonality is excellent with the AHB2.

As for depth, I am not quite sure what you mean in the context of modern recordings. In the studio I don't know how engineers manufacture depth. I know how sound is placed in the the horizontal plane using panning. But the other two dimensions...?

However, depth can certainly be heard when the recording captures the ambient queues of the recording venue. In that respect the AHB2 is also excellent. It is funny that you mentioned this because I heard an EXTREME example of this last night - the likes of which I have not heard before.

Since yesterday was so nice, I will throw in this little anecdote. We went out yesterday afternoon to eat street tacos and drink margaritas with some friends. After getting pretty happy, we walked across the street. There was a new vinyl shop there. Of course I had to drag everyone in. What do you know... the owner is a good friend of mine, recently retired, who had closed down his old shop over a year ago. I had lost touch with him. Seems a divorce revitalized him, and he decided to get back into the business again. Great to see him. Anyway, we bought about a dozen records from him for about $35. One of them was the record I am referring to.

The vinyl is "Arkiv Productions - 198 318, Antonio Vivaldi" recorded in the mid-sixties in a church in Berlin. It consists of four concertos for various instruments. On one side of the album there is a concerto, "Concerto con Violino Principale et Altro Violino per Eco in Lontano" which means "Concerto for Principal Violin and Other Violin for Echo in the Far". I only just now translated this. Aahha!!!

While I was listening I was puzzled in the extreme as to what was going on in the recording. I seems that Vivaldi actually wrote this in order to achieve an echo effect. Back then the only way to do this was to put pieces of the orchestra at greater distance from the main orchestra in a large church. This was rendered with eyebrow-raising precision with the AHB2.

You can hear three distinct depths. There is the main orchestra and soloist at the first level. Then there is a small group of strings at the next level- maybe 20-30 feet back. The echo chamber instruments were placed at the third level WAY in the back of the church (which has a lot of reverberant energy). The effect is really interesting, and the engineers captured it very well. You hear the main orchestra and when they are silent or only the violin soloist is playing, you sometimes here this island of strings much further back at the second level. And when Vivaldi whats the full echo, you hear the third layer very far away. Subjectively it sound like they are almost one hundred feet back. They may well have been.

So here you have a recording with very deliberately recorded depth perspective. The AHB2 made it clear to me what I was hearing. I just couldn't figure on why the recording was done that way. As I begun to write this, I translated the Italian and it is clear that this is exactly what I was meant to be hearing. Cool, huh?

Now, this is such an extreme example that the most mediocre system would hand you back a good deal of this. But with the AHB2, you are not guessing at all as to what is going on.

Other classical recordings where depth is know to be consistently and naturally captured are the Mercury Living Presence recordings and the RCA Shaded Dog series. These sound as I would expect on the AHB2. If I recall correctly, the NAD struck me as a little bit flatter. But I am going to stick with the AHB2 for a another week or so before comparing to the NAD.

As far as tonality is concerned, we also picked up an album that was fairly ubiquitous in the sixties for 50 cents - in great condition. Misa Criolla. There are 4 pages of fine ink drawings in the gate fold. This is an excellent Phillips recording. The voices in the choir are exquisite and very well delineated. You couldn't ask for more, and the AHB2 delivered.
 

RichB

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Better than the best phono cartridge ever made. I don't know the literature, but in my own tests, I could detect no differences when it was as low as -30. Do you have a reference that suggests otherwise?

On this thread, I suggest and SINAD of -113dB, anything less will not do :p

Best Audio Amplifiers 2019 Reviewed.png


Of course, I don't have any reason to believe that every amplifier in this chart will be indistinguishable with the usual caveats, driven within their limits.

- Rich
 

SIY

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Try doing the inter-amp comparison blind and level matched. Otherwise, it's alien abductions and story-telling.
 

maty

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Arkiv/Archiv is a quality label, you knew what you were buying!

Must be: https://www.discogs.com/Antonio-Vivaldi-Concertos/release/8305762

R-8305762-1478358391-1368.jpeg.jpg


A1 Concerto Pou Flûte Piccolo En Ut Majeur, P. 79

A2 Concerto Pour Violoncelle En Ut Majeur, P. 434

B1 Concerto Pour Violon Principal Et Autre Violon En Écho En La Majeur, P. 222

B2 Concerto Pour Violle D'Amour, Luth Et Tous Instruments À Cordes En Sourdine, En Ré Mineur P. 266


I have a lot of antique music, from Vivaldi a lot too but I do not have that recording. Take note, thank you very much. I think we would spend hours talking about good recordings and vinyl pressings.
 
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SIY

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A
Why? I suspect that has too much global negative feedback -> good/very good specs, but sound?

So... putting aside the inanity about feedback, do you have anything that isn't based on peeking and preconception, something involving actual ears-only listening? Third try asking.
 

Blumlein 88

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I agree, one-shot or few-shot learning can only happen if the novel category differs from the familiar ones by a lot. For finer discrimination you will need many more examples stretched over a calendar period. I do wonder if casual listening to my own amp over a long time would suffice for such fine discrimination.
There is no good evidence this would so. Short side by side comparisons are the most discriminating by far. Part of the problem is echoic memory. For a few seconds you have direct access to the actual sound heard in short term memory. Then it gets processed by your brain and the version in long term memory is something like a compressed partial version of the real perception. Think of it like an MP3 of the original event.
 

maty

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Being a suspicion it is evident that I do not have it confirmed. But I trust others who say so.
 

DonH56

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How people feel hour-to-hour and day-to-day (and so forth) is a huge player in what sounds good/different at the time IME/IMO. Properly done level-matched ABX/DBT testing with rapid switching takes that long-term physiological/emotional stability out of the equation. Certainly long-term trends can be valid, but what if the long-term trend is based upon e.g. two components that are not level-matched? What if you listen to the new amp a little louder just to hear how good it sounds, and then switch back to the old one at a little lower level? The lower level means the older one won't have as much bass, may not sound as "warm", etc. There are just way too many variables to screw up for me... I have to either do a good ABX test or pull out the measurement gear.
 

orangejello

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Arkiv/Archiv is a quality label, you knew what you were buying!

Must be: https://www.discogs.com/Antonio-Vivaldi-Concertos/release/8305762

A1 Concerto Pou Flûte Piccolo En Ut Majeur, P. 79

A2 Concerto Pour Violoncelle En Ut Majeur, P. 434

B1 Concerto Pour Violon Principal Et Autre Violon En Écho En La Majeur, P. 222

B2 Concerto Pour Violle D'Amour, Luth Et Tous Instruments À Cordes En Sourdine, En Ré Mineur P. 266


I have a lot of old music, from Vivaldi a lot too but I do not have that recording. Take note, thank you very much. I think we would spend hours talking about good recordings and vinyl pressings.

Yes that is it - although I got the original pressing which has a very matte, almost cardboard, gate-fold cover - lucky me.

And yes, - I will pat myself on the back here - I know quite a bit about this stuff and enjoy sharing it with others who like that sort of thing. I have a vast collection of jazz on vinyl with many versions of the same recordings which differ due to re-mastering and pressing. It is fun to compare them, albeit not very worthwhile unless you have good enough equipment to hear the differences.

If you are familiar with the Westminster mono classical recordings from the early to mid fifties - many of these used to sell for a small fortune in Japan. I found the entire collection (around 200 records) preserved in leatherette cases (ten to a case). At the most, I would guess, they had been played once, if at all. The covers all looked like they were printed yesterday. I knew precisely what I was doing when I bought these for $4 each. Many of the performances are not only beautiful, but also historic in the sense that the musicians have deep roots in their training that shows a direct lineage back to the composers whose works they preform. And the musicians themselves were the very best of what Europe had at the time - dedicated, educated, sensitive, and accomplished. They were not products of the marketing divisions of large records labels. And the mono recordings and pressing are terrific. A lot of vinyl from back then was petty poor, and this makes much of the stuff from that period hard to listen to unless you are a something of a musicologist. This was not the case with the Westminster red and green label originals. The vinyl is an example of the best of that period. In any case, I listened to them, enjoyed them, and then sold them off to the Japanese market - where such things are appreciated and revered.
 

maty

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I am not familiar with the Westminster mono classical recordings from the early to mid fifties.

I am afraid that if we continue commenting on the good sound and the quality of many vinyl recordings, many will give them an attack of disbelief. They think that everyone sounds bad, with clicks, rumble ... it is what has to generalize.

Well, that, we are fortunate to be able to enjoy so much wonder that many despise.
 

GrimSurfer

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I am not familiar with the Westminster mono classical recordings from the early to mid fifties.

I am afraid that if we continue commenting on the good sound and the quality of many vinyl recordings, many will give them an attack of disbelief. They think that everyone sounds bad, with clicks, rumble ... it is what has to generalize.

Well, that, we are fortunate to be able to enjoy so much wonder that many despise.

I'm sure they sound brilliant after having been played "n" number of times in 50 years on turntables ranging from mechanical to brushless.

I try to recreate the same aura by microwaving cassettes before playing... or lovingly polishing my CDs with sand before throwing them into the tray from across the room. It adds so much... sparkle and a sense of air to my music.
 

zalive

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This is a widely proposed view but actually I think this serves only as a way to make you feel that you have made a good choice in your own mind but there is actually no way to make comparisons of any validity in the long term IME.
I haven’t changed much of my main kit for 20 years, though I have messed around with other stuff and have secondary (and other) systems.
During these 20 years I sometimes think to myself whilst listening how fantastic it is sounding.
I actually have no idea why, could be a particularly good sounding recording I am listening to (IME the recording quality is massively more important for SQ than the hardware we use to play it on which makes a mockery of Hi-Fi in a way anyway), it could be my mood, some furniture I have moved or something, but the one thing it can not be is a change in my Hi-Fi, since there hasn’t been one.
If I had bought something new I could easily believe it was better than my old system by evaluating long-term and I would be completely wrong.
I used to think the idea had some truth in it but now know there isn’t, one of the things I learned over the last 50 years of playing around with Hi-Fi.
The only way I have found which tells if there really is a difference is precisely level matched direct and immediate comparison.

I completely agree for the recording quality. It turned out that a good deal of reason why digital (CD) got a bad reputation was on poor technical and human (mastering) job in making CD-s. It's actually funny to see that it took couple of decades to learn how to do it properly and to support it with quality equipment. Now a listener can easily see how good a 44.1/16 format can get with a great recording - makes you wonder what you need more? And it indeed can sound analog-like when it was properly done.

Anyhow, I don't see anything wrong with your approach. If a long term evaluation satisfies you, the objective picture is completely unimportant. Unless something changes in your subjective perception in yet longer term, so at one point you realise you're not as satisfied as you were initially ;) in which case you need to ask yourself, was your evaluation a complete failure? Were you deluding yourself instead of making a proper evaluation? Are you personally capable of doing it, or should you change your approach? However it this should not happen...who cares what's underneath? If this approach leads you to satisfaction, it's good anyhow you interpret it.
 
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