Benchmark AHB2 Review (Updated Measurements)

[Kal Rubinson]

entirely agree and i dont think i said anything that contradicted that premise, rather re-enforced it.

Apologies if I made it seem otherwise.

 

[Docmoggy]

Your “Valhalla” has already been reached years ago. The rest is GAS.

In your opinion. Mine is, knowledge is a virtue.

 

[Martini]

We're working on removing the math from science. Things will be communicated with arm waving and body motions

and speaking loudly.

 

[Platypus20]

and speaking loudly.

And I’m guessing finger gestures…..

 

[pogo]

Discussion (and testing) to resolve apparent anomalies, like this one, is necessary.

I wouldn't call it an anomaly. Duncan described it quite well in his publication and it is not so easy to calculate which hardware influences are more important here, as the DF is multidimensional and we have no data on the UUTs in all areas of operation. The two-dimensional FR approach is not adequate here.
In particular, we lack them for transients. A simple test setup here would be with a T+A A200, which offers a switchable DF. This would make it possible to work out the differences with minimal effort, i.e. make them measurable.

 

[Geert]

A simple test setup here would be with a T+A A200

According to the forums search function that's the 33th time you dropped this amplifiers name in this context on the forum. You've been doing so for years, but still you have nothing more to report on this "simple test"? Is this how people think we should "expand our understanding of phenomenons"?

 

[AdamG]

I wouldn't call it an anomaly. Duncan described it quite well in his publication and it is not so easy to calculate which hardware influences are more important here, as the DF is multidimensional and we have no data on the UUTs in all areas of operation. The two-dimensional FR approach is not adequate here.
In particular, we lack them for transients. A simple test setup here would be with a T+A A200, which offers a switchable DF. This would make it possible to work out the differences with minimal effort, i.e. make them measurable.

Find a suitable Damping Factor Thread or start a new thread. This is now becoming a “general Amplifier Damping Factor” conversation and as such is driving this thread off topic for the Reviewed Product.

Thank you for your cooperation and understanding.

 

[fpitas]

No we aren't. Established models work until we observe a pehenomenon in which they dont.

I am not claiming that is the case here with audio, my domain expertise here is no better than anyone else contributing to the topic.

But just note that science is a journey to expand our understanding of phenomenons that puzzle our established models. Science would stop if we had established the perfect "truth" with our existing models. We havent.

And we should.also note science doesnt concern itself all that much finding reasons -or has established a theory- about why some of us are more receptive to abstract art than realistic photography or impressionism etc etc. Which doesnt mean I defend completely irrational snake oil subjectivism in audio at all.

Uhm...did you really mean to reply to me? That was simply an off-hend "joke".

 

[fpitas]

Although if we do succeed in replacing math, it may take synchronized dancing to explicate multi-dimensional calculations.

 

[pjug]

Conclusions
Using standard binding posts reduces performance just a bit but certainly nothing to worry about. What we have is still state of the art and one of best ever consumer stereo amplifiers produced.

I would like to see what happens if you measure the amplifier at the load end of a length of cable. Not the way to do it to show the actual amplifier performance but this is what the speaker gets. My assumption has been that then you wouldn't see any performance difference between speak-on and regular binding posts.

 

[wilbur1]

The Model 4 is a Michael Bladelius (and not Nelson Pass) design. It's an interesting amplifier in that utilizes IGBTs and is based on an approach that is the complete opposite of Benchmark in that the aim is to make it feedback-free. (See the attachment for a very broad overview and the usual marketing mumbo jumbo.) I searched long and hard but found no real measurement-based information about it. Simply "0.1%" THD at what I presume to be 50W at 8ohms at 1kHz, which should mean that it will do the job. The manual of the matching F44 preamp has a little more information, though nothing that would satisfy anyone here. To these ears it sounded as clean as the NAD 320BEE, which is a compliment, lol! (Though that 90 dB SINAD is no joke.)

The only audibly bad sounding piece of equipment (non-speaker) I ever owned was a Conrad Johnson Motif MC-8 preamp. The mental gymnastics I must have done to tell myself that it was good... "Sweet." "Syrupy." Ugh, what a fool I was.

Edited to add a little more info.

Interesting. I found this online: Nelson Pass (in a Sterophile interview in 1992) said that the input stage on the Forte 4 (amongst others) had some of his circuits, but Michael Bladelius was the primary designer. Nice to know.

 

[fpitas]

My assumption has been that then you wouldn't see any performance difference between speak-on and regular binding posts.

Well, maybe. If the effect is simply resistance, you're right. If the effect is from a non-linear connection, not so much.

 

[AdamG]

Find a suitable Damping Factor Thread or start a new thread. This is now becoming a “general Amplifier Damping Factor” conversation and as such is driving this thread off topic for the Reviewed Product.

Thank you for your cooperation and understanding.

Have already asked to take the Damping Factor conversion to a separate thread. If it continues posts will be deleted and thread bans handed out. Rather not do that, so please comply with this ask.

Here is a link to an existing Damping Factor Thread : https://www.audiosciencereview.com/forum/index.php?threads/damping-factor.48232/page-6


Thanks

 

[Chester]

Bringing things back to the AHB2, as a recent owner of a pair of these, I have to say I was a little nervous when Amir said he would be re-testing but glad to see they performed equally well as first time around.

Coming from Purifi amps, I have been thoroughly impressed with these mainly due to their form factor, aesthetics and build quality.

They sound excellent, as did the Purifi’s.

 

[Overseas]

Bringing things back to the AHB2, as a recent owner of a pair of these, I have to say I was a little nervous when Amir said he would be re-testing but glad to see they performed equally well as first time around.

Coming from Purifi amps, I have been thoroughly impressed with these mainly due to their form factor, aesthetics and build quality.

They sound excellent, as did the Purifi’s.

So you replaced Purifi for form, look and build?

 

[Chester]

So you replaced Purifi for form, look and build?

I did. I still have them for now and will likely keep one.

 

[Chester]

I should add, I was looking for a smaller form factor amp and was close to pulling the trigger on an Apollon Mini, but saw 2 AHB2’s used, both immaculate and manufactured late 2020, for the same price as a new AHB2 here in the UK. Felt like a no regrets purchase at that price.

 

[theREALdotnet]

Although if we do succeed in replacing math, it may take synchronized dancing to explicate multi-dimensional calculations.

You haven’t seen matrix multiplication until you’ve watched it performed by a highly trained dance company.

 

[pablolie]

Uhm...did you really mean to reply to me? That was simply an off-hend "joke".

apologies for my damp holiday context disconnect... :-D

 

[DMill]

This has been an interesting thread with many opinions on chip amp superiority. I’ve always considered Benchmark amps to be SOTA and I still feel that way. I‘d love to see their take on a Class D design. I have a feeling it would be every bit as much impressive. I always thought McIntosh did a great job with legacy products while continuing to stay current. Binghamton (Mc) and Syracuse (Benchmark) are about an hour apart by car on I-81 btw. Maybe it’s the upstate NY pride I have cause I’m lucky to live close, but one is already the standard for amps and the other keeps setting the Benchmark.