Review and Measurements of Benchmark AHB2 Amp

[Heyu]

Is low distortion good even if you can't hear it or don't play loud? I realize it's clean power having low distortion but from one amp to another does it matter if it's inaudible?

 

[fpitas]

Is low distortion good even if you can't hear it or don't play loud? I realize it's clean power having low distortion but from one amp to another does it matter if it's inaudible?

Probably not. Although conceivably crossover distortion *might* be audible at very low listening levels with very sensitive speakers. Which is why Benchmark went to great lengths to fix it.

 

[MaxBuck]

Although I'm extremely satisfied with my NAD C298, there are times when I wish I'd bought this Benchmark, if for no other reason than supporting excellent American engineering.

 

[Gaussgodden]

You're going to have almost 400 watts to play with -- yeah, it'll get the bass going.

I have monoblocks on my wilson alexias and they will shake the floor (though with a little bit more power available as they're 4-ohm)

The 801 matrix is notoriously hard to drive.. I've driven it with Bryson 4b it just doesn't sound like the bass is fully extended like the passlab x350 even at low volume. I was just wondering if benchmark would have such issue driving the 801 matrix s2

 

[xaxxon]

B&W Matrix 801 Series 2 loudspeaker Measurements

Sidebar 2: Measurements Stereophile's analysis of the B&W Matrix 801 was published long before the magazine acquired the DRA Labs and Audio Precision measurement systems used for its loudspeaker reviews. As my wife owns a pair of the big B&Ws, however, I have measured the speaker at various...

www.stereophile.com

https://www.stereophile.com/images/archivesart/bwll801fig01.jpg

impedance and phase look pretty sane.

87dB(B)/W/m

sensitivity looks a little low but still reasonable.

so it'll hit 107db (100w) with one or 113 (slightly under 400w) with two.

30-Day Risk Free Trial

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benchmarkmedia.com

No restocking fee on amps, so there you go... get one (or two) and try it

 

[Heyu]

B&W Matrix 801 Series 2 loudspeaker Measurements

Sidebar 2: Measurements Stereophile's analysis of the B&W Matrix 801 was published long before the magazine acquired the DRA Labs and Audio Precision measurement systems used for its loudspeaker reviews. As my wife owns a pair of the big B&Ws, however, I have measured the speaker at various...

www.stereophile.com

https://www.stereophile.com/images/archivesart/bwll801fig01.jpg

impedance and phase look pretty sane.

87dB(B)/W/m

sensitivity looks a little low but still reasonable.

so it'll hit 107db (100w) with one or 113 (slightly under 400w) with two.

30-Day Risk Free Trial

30-Day Risk-Free Trial (United States Only) Audition Select Benchmark Products With No Obligation: The only way to fully appreciate the performance of our products is to try them in a familiar listening space. With our 30-Day Risk-Free Trial, you can audition select Benchmark products in your...

benchmarkmedia.com

No restocking fee on amps, so there you go... get one (or two) and try it

You do have to pay for return shipping though.

 

[pma]

You do have to pay for return shipping though.

At least something has been left on customer's responsibility - this "try and return" system is widely misused by customers.

 

[Papillon]

is there any difference that can be heard by a human between this AHB2 and some excellent Purifi implementation like Boxem or Apollon?

 

[Purité Audio]

I compared to March Audio’s Hypex and then Purifi amps I couldn’t hear any obvious differences.
But by the time you have disconnected one amp, connected up the other…
I wouldn’t expect there to be any difference in sound quality as long as they can properly drive the loudspeaker in question.
Keith

 

[Papillon]

Thanks a lot Keith for the answer! indeed that's what I expect too...I should receive an ahb2 for test soon. i'll compare it with my Boxem Purifi that I have at home for the moment on some songs I know very well.

 

[Jasperous]

I would like to share my experience with Benchmark AHB2 and LA4. Few weeks ago I started to make some changes in my system regarding amplification. During last 3 weeks I have been listening to 5 amplifiers: VitusAudio RI-100, MacIntosh MA352, Technics SU-R1000, Canor AI 1.20 and Benchmark AHB2 with LA4. I do not want to go into audio-poetry so I will list those amplifiers from worse in terms of clarity to the best:

Worst overall was Vitus (for me this brand is hugely overpriced)
McIntosh was much better than VA but worse than Technics in precision and detail.
Differences between Technics and Canor were quite subtle but noticeable.
The last two Amplifiers were very hard to differentiate. I am still not sure if I would pass a blind test. I con not find any measurements of Canor amplifier. On their web site they wrote that Canor THD is <0,0009% / 1 kHz, 5 W https://www.canor-audio.com/canor-ai-1-20
It is pure class A solid-state amplifier.

Finally I chose Benchmark because I think that on some very dense music material Benchmark showed more detail and kept sound characteristic that I like. Other factors were that Canor is humming very slightly when you put ear very near chassis. Also Benchmark stays cool and take much less power.

Benchmark is truly excellent amplifier and is brutal for every fault in recording. I observed that some recording were less painful on Technics or Canor most probably because of masking effect. But you hear this effect only when you can compare with transparent amplifier.

Yeah, I had a Yamaha A-S2000 and when I switched to the Benchmark it was night and day! Even my old Polk Rti-A9 sounded like completely new speakers!! The mid-range and highs coming off it were significantly better! And the Benchmark weights nothing compared to the old dinosaurs! It's just really good design!

 

[SIY]

Worst overall was Vitus (for me this brand is hugely overpriced)
McIntosh was much better than VA but worse than Technics in precision and detail.
Differences between Technics and Canor were quite subtle but noticeable.
The last two Amplifiers were very hard to differentiate. I am still not sure if I would pass a blind test. I con not find any measurements of Canor amplifier. On their web site they wrote that Canor THD is <0,0009% / 1 kHz, 5 W https://www.canor-audio.com/canor-ai-1-20
It is pure class A solid-state amplifier.

Finally I chose Benchmark because I think that on some very dense music material Benchmark showed more detail and kept sound characteristic that I like. Other factors were that Canor is humming very slightly when you put ear very near chassis. Also Benchmark stays cool and take much less power.

Benchmark is truly excellent amplifier and is brutal for every fault in recording. I observed that some recording were less painful on Technics or Canor most probably because of masking effect. But you hear this effect only when you can compare with transparent amplifier.

Was this all done without basic controls (level matching, double blind)?

 

[SIY]

I matched volume level but have not done any blind tests. I do not have equipment for that. I know that my observations are not scientifically accurate but this was not my purpose.

Probably best not to make those claims about sound without doing basic controls.

 

[PatF]

Probably best not to make those claims about sound without doing basic controls.

I see that this forum reached total level of absurd.... Ok np. I will not write any impression about audio gear without examination on the University level....

 

[yyzsb]

When the AHB2 is used as a mono does it suffer in that it sees lower impedance for a given load. I am not technically astute in these matters so maybe I am not asking this question correctly. I have been told that an amp designed for stereo operation (like the AHB2) suffers in performance when used as a mono amp. Now some amps are specifically made for mono only operation and do not suffer the gremlins from stereo to mono.

Is this something that applies to the AHB2?

I have some new speakers, the Yamaha NS5000, and I am looking for some amplification. I am currently using a fantastic modded 200-watt Peachtree GAN1. However, that 'amp|dac|pre' is not easy to use since I need to use software for the volume control (via ROON) and I only have 1 SPDIF GAN1 input. I need a preamp with a few analog inputs. I have the Holo Serene pre and Benchmark LA4 pre to work with the NS5000 (likely the LA4) and some future amp.

The NS5000 specs

NS-5000 - Specs - Yamaha - UK and Ireland

Introducing Yamaha’s flagship 3-way bookshelf speaker system, setting a new standard in performance and quality by which all other Hi-Fi speakers should be judged.

uk.yamaha.com

 

[RichB]

I see that this forum reached total level of absurd.... Ok np. I will not write any impression about audio gear without examination on the University level....

It is fine to state your opinions, IMO of course

- Rich

 

[Sal1950]

I see that this forum reached total level of absurd.... Ok np. I will not write any impression about audio gear without examination on the University level....

You make totally unsupportable audible claims using absolutely no controls and call us "absurd"?

 

[PatF]

You make totally unsupportable audible claims using absolutely no controls and call us "absurd"?

are you happy now ?

 

[Doodski]

are you happy now ?

If you have something subjective to say just delineate it as being subjective...lol. You'll be fine..RFLMAO.

 

[tmtomh]

I know this sounds wishy-washy, but I can appreciate @PatF 's report even though I cannot argue with @SIY 's point that sighted comparisons, particularly ones not rigorously level-matched, are of limited use (to put it politely) as generalizations.

That said, such reports often spur interesting questions for me, and in this case I wonder if the Benchmark is revealing flaws in the recordings Pat is listening to, or if perhaps it is playing at a slightly different gain level and is exciting/activating certain nonlinearities or characteristics of the speakers and the room. This is not in any way to try to criticize Pat's setup. I'm just saying that the Benchmark is kind of an odd duck when it comes to its gain, which I would imagine makes it particularly difficult to precisely level-match in comparison to other amps. I know I don't trust my ears to level-match two sources beyond the level of "roughly similar" - and based on the scientific literature I've read, "roughly similar" is not sufficient to eliminate volume level variation as a potential source of sonic differences we hear. This is especially true because because the volume sensitivity of our hearing is nonlinear, so a small difference in volume sounds like a loudness contour (or perhaps a reverse loudness contour), which can be very deceiving.