Review and Measurements of Benchmark AHB2 Amp

[sarumbear]

The AHB2 will not work well in bridge mode either,

Why? What do you find wrong with this test?

Review and Measurements of Benchmark AHB2 Amp

This is a review and detailed measurements of the Benchmark AHB2 Amplifier using THX technology to reduce distortion. I was going to request one for testing due to membership demand but to my pleasant surprise, the company volunteered to contact me and send not one, but two units! I requested...

www.audiosciencereview.com

 

[Pearljam5000]

I'm just wondering why would anyone buy amps that cost 10-30 times more
like Dan D'Agostino or Gryphon etc if this amp is so good

 

[the_surf_doc]

I'm just wondering why would anyone buy amps that cost 10-30 times more
like Dan D'Agostino or Gryphon etc if this amp is so good

I can give an example. I was lucky enough to own some expensive Italian cars a few years ago. The more familiar I got with these cars, the more I'd find items of workmanship that frankly weren't acceptable to me. Cheap switch gear. Dodgy electrics. Critical parts (e.g. clutch) that were not fit for purpose, wearing out after 10,000 miles. Semi-automatic gearboxes that couldn't change smoothly.

In sum, the performance and reliability wasn't up to par.

I now drive a far cheaper car from the same broad company ownership. It's a different marque but has the same switch gear. The gear changes are perfect. No fancy badge. But, it gets the job done.

Exotically priced amps can sell on looks, style and marketing. They may even be works of art in and of themselves. I owned a Chord Dave until about a week ago. It is a work of art to look at. But as soon as I saw its poor measurements on ASR, I traded it in.

 

[GXAlan]

I'm just wondering why would anyone buy amps that cost 10-30 times more
like Dan D'Agostino or Gryphon etc if this amp is so good

I was recently comparing the Marantz PM-10 against the Arcam SR250. I own both and both are out of return windows, etc.

Even though my REW sweep with Dirac/SR250 is flatter and it lets me introduce a nice bass boost from correcting the room, the PM-10 sounds better.

It’s a big enough difference, I was thinking about finding a good enough ambisonic or binaural mic to put it up to a blind test here at the readership.

As is the case with my 300B tube amp testing, there is a paradox that transparency might not sound as pleasant as a bit of coloration. It is still unclear if this is all sighted bias, but sighted bias genuinely does affect perception and maybe that’s a good tool to use as well to enhance the ultimate listening experience.

No matter how hard I try, I cannot mentally force myself to see A and B as the same color… it’s only when I remove all of the distractions and block out the rest of the image do the colors blend.

For all we know, fMRI might show sighted bias enhances audio in a way no other mechanism can…

Edit: Along those same lines, I have had my Bose 901 for a reasonable time now. It’s very true that the in room experience of the 901 is unpredictable but gosh, I hit the lottery and it works great in my room. I have compared it to Dirac and I am lucky enough that the uncorrected version is nearly identical. The uncorrected version actually has a more precise phantom center as well! I have tried Dirac with other much more expensive speakers that I already own, better measuring speakers, etc. In this case sighted bias and prejudices actually worked against me since I was expecting much less. Discovering the Bose 901, paired with a lucky room and good electronics, has saved me a lot of money as I have been able to sell some of the stuff that is worth much more.

So sometimes, the more expensive stuff genuinely sounds better and sometimes the cheaper stuff sounds better.

 

[USER]

I had an SHD driving balanced AHB2 to Revel F228be. I believe I was using mid-gain (which matches the SHD's 4V output). I could get up to maybe -12 dB tops before I had to turn it down, with a 3-4m listening distance. My normal listening was around -30 to -40 dB, IIRC.

Same experience with Revel F226Bes. Pretty much the same set-up. I have not purchased a second AHB2 because of this. I normally listen to music at somewhere between -18 to -28dB. And I am rocking out at -18dB though I cannot listen at that level for too long. Nothing like the feeling of a totally energized room, however.

I will say that the only "issue" I have is with my TV (optical out), which requires higher volume depending on the source. HBO Max on Chromecast TV, for instance, requires setting the SHD to about that level, -12dB. Still, no clipping.

 

[radix]

TLDR
So basically is this the best amplifier ever made ?

If it meets your power requirements (stereo or bridged), then yeah, it's about all you would need.

Now, some might want a specific visual aesthetic or style for their space. If that is important to you and the AHB2 does not fit it, then go get what works for your style. Each person values different things. Some want the best value, some want the cleanest sound or most neutral sound, some value style and how the machinery fits into a the room. They are all valid personal points of view.

 

[pogo]

Why? What do you find wrong with this test?

There is nothing wrong with the review. It just doesn't cover all relevant and audible data. But this can be found in other reviews, see also here: Link
The effects can be calculated depending on the speaker used, see also here: Link

The determined DF values by STEREO apply to the unbridged mode!

Can it be that you could see such deviations in the test here (performed for NAD M23), which is carried out recently?

 

[Geert]

There is nothing wrong with the review. It just doesn't cover all relevant and audible data. But this can be found in other reviews, see also here: Link

As already confirmed by others more than a month ago when Pogo first dropped these numbers:

1. https://audiosciencereview.com/foru...ments-of-benchmark-ahb2-amp.7628/post-1320948
2. https://audiosciencereview.com/foru...ments-of-benchmark-ahb2-amp.7628/post-1306179

Summary:
"Their measurements indicate that their load is not fit for the task - neither is their measurement equipment. And without even saying what they could achieve in bridged mode this looks more like an attempt to keep their usual advertizers happy... I for one had no problem (except for getting better loads first) to reproduce @amirm 's stellar results with my own AHB2".
"Stereo.de AHB2 damping factor measurements is an outlier. I have no idea what Stereo.de is doing, and perhaps they don't either".

John Siau confirmed on this forum they guarantee the performance of this amp up to loads of min. 1.4 ohm.

But Pogo can' t resist trolling.

 

[pogo]

Can it be that you could see such deviations in the test here (performed for NAD M23), which is carried out recently?

Such a test would also be more representative at different frequencies and volume levels.

 

[sarumbear]

There is nothing wrong with the review. It just doesn't cover all relevant and audible data.

So, tough! It is a free test.

What is your definition of "not work well," please.

You said "The AHB2 will not work well in bridge mode either." What is the other problem you see that will make the unit not work in bridge mode? (As you used the word either, there must be more than one problem you see.)

 

[SIY]

So, tough! It is a free test.

What is your definition of "not work well," please.

You said "The AHB2 will not work well in bridge mode either." What is the other problem you see that will make the unit not work in bridge mode? (As you used the word either, there must be more than one problem you see.)

He's been slinging that "damping factor" bullshit for a long time, without ever offering a shred of evidence that past a moderately low source impedance there is any relevance. It's no less bullshit from repetition.

 

[pogo]

You said "The AHB2 will not work well in bridge mode either." What is the other problem you see that will make the unit not work in bridge mode? (As you used the word either, there must be more than one problem you see.)

See my post #3324 related to the KEFs.
AHB2 manual:
Make sure the nominal Bridged MONO load impedance is 6 Ohms or higher

 

[sarumbear]

See my post #3324 related to the KEFs.
AHB2 manual:
Make sure the nominal Bridged MONO load impedance is 6 Ohms or higher

Please read the following paragraph as well.

 

[RichB]

See my post #3324 related to the KEFs.
AHB2 manual:
Make sure the nominal Bridged MONO load impedance is 6 Ohms or higher

Here are the measurements from the review, post 1.

There have been many posts by users driving the Salon2s with bridged AHB2s.

There seems to be an obsession with NAD(s).

- Rich

 

[pogo]

Could it be that the Revels represent a simpler load (see also impedance curve, EPDR values, ...) than the KEFs?

 

[Geert]

AHB2 manual:
Make sure the nominal Bridged MONO load impedance is 6 Ohms or higher

 

[PGAMiami]

Please read the following paragraph as well.

View attachment 293352

I’m using bridged AHB2s on TAD R1s. They are a match made in heaven. Absolutely no problem driving these, have never clipped the amps even at levels you would not want to listen to, even using the R1s full range without subs watching things blowing up in a home theater set up

 

[PGAMiami]

Who recommended an AHB2 to you?
The AHB2 will not work well in bridge mode either, as the minimum impedance is similar to a Dali Kore. On the Dali, even a NAD M33 proved to be potent enough last time at a hifi show. The pure power amp section from the M33 is the M23.
The minimum EPDR values of the Meta can probably also be transferred to your speaker: Link

The AHB2 in bridged mono is the best amp I’ve ever owned in a list of many amps up to 10x the price. Amps can clip either from running out of current or voltage. The bridged AHB2 has plenty of both. In bridged mode it’s more likely to run out of current if you push it absurdly high, but that will probably damage your ears or speakers first. It’s a near perfect amp until it clips, and then it shuts down. Mine have never shut down.

 

[fpitas]

I'm just wondering why would anyone buy amps that cost 10-30 times more
like Dan D'Agostino or Gryphon etc if this amp is so good

The straightforward answer is, they think they're getting better performance.

 

[Ron Texas]

My view is this is a well designed amplifier which has also become an object of desire around here because it measures so well. In actual use I doubt it sounds any better than a far less expensive NC502 which does not measure as well, but is good enough have inaudible distortion. Genelec monitors have achieved a similar status. A single number becomes the alpha and omega which in the minds of some makes all other loudspeakers irrelevant.