Benchmark AHB-2

I wanted to create a thread for this wonderful power amp from Benchmark.




PRICE

• $ 2,995.00 USD

CONTINUOUS AVERAGE OUTPUT POWER
1 kHz, < 0.0003 % THD+N

• 100 Watts per channel into 8 Ohms, both channels driven
• 190 Watts per channel into 4 Ohms, both channels driven
• 380 Watts Bridged Mono into 8 Ohms

SNR & DYNAMIC RANGE

• 132 dB A-weighted, Stereo Mode

MAXIMUM AUDIO OUTPUT CURRENT

• 29 A peak, per channel, both channels driven

DIMENSIONS
NON-RACK-MOUNT VERSION:

• 11.04" W x 3.88" H x 9.34 " D - Including feet and binding posts

FULL SPECS AND MORE INFO ON WEBSITE:

https://benchmarkmedia.com/products/benchmark-ahb2-power-amplifier

BRIEF IMPRESSIONS

I've spent a lot of time with the AHB-2, almost 6 hours every day for the last week and a half. I recently compared it to my Zana Deux using HD800 and HD650, which I feel present stage width and depth more accurately than planars and the AHB-2 doesn't give up much of anything in terms of staging. It's honestly shocking. It has possibly better width but slightly less depth than ZD.

With the dynamics it isn't as warm and smooth, as it's meant to be as transparent as possible. HE-6 though, is definitely more muscular out of the AHB-2. I thought Jot had excellent bass response with HE-6 but AHB-2 gives it a little extra weight, yet has all the air and clarity you would expect.

Best part about the AHB-2 is that it doesn't even get warm, like, at all. I've been using it with Freya (tubes pulled) in strictly passive mode and have a system that can be used for hours without adding any heat to the room, which is huge since it's still in the 100's in Arizona.

Feel free to add your impressions and ask any questions you might have for owners of this excellent power amplifier.

Obligatory pics of my system with the lucky transducer...

 

Nice compact size! I'm thinking about getting one to ran code-x on , might be an overkill tbh but this looks like great power amp with plenty of power.
Did you have to put any resister on the adapter?

 

If it can run HE-6 it will surely do Code-X justice. I'm getting my HE-6 Code-Xed and Luis said it will be even harder to drive but so worth it.

 

I was really surprised that the D-Sonic loaner didn't run as cool as the AHB2.

 

This little gem does a lot right, assuming the rest of the gear is up to it.

 

Another reason it runs cool is that it uses an SMPS instead of linear power supplies. I found this article while I was looking up ways to keep my power supply noise as low as possible.

https://benchmarkmedia.com/blogs/ap...audio-myth-switching-power-supplies-are-noisy

 

Yes it is a digitally managed power supply, which makes this amp a class H

 

Yes. Even being class H, I was still quite surprised at how cool it runs (not "only warm as opposed to hot" but actually cool).

 

Not to rain on anyones' parade, but the 132 dB A-weighted claims causes me some pause. What is the UNweighted noise floor, dynamic range, etc?

Even better, look at the 1 KHz, and multitone spectrums. What shows up at below 120 dB down from signal under a modest load, say 10W?

A-weighting can hide a lot. Look at an A-weighing curve to see how it is a high pass filter that attenuates 60Hz mains noise by approximately 27 dB:

curve data from IEC / ISO 61672.

 

@atomicbob on the specs page they show 130dB 20Hz-20kHz single ended, 133dB mono. Lots more information there as well.

It would be a great amp for you to measure.

 

Benchmark does it the benchmark way, there's no changing that. Besides, is there anyone here who's actually trusting numbers coming straight from the marketing dept of whatever audio company?

 

Well, there's the quiescent current heat and heat based on power output. I agree that at home most amps will run at around 1 - 5W continuous output with higher peaks which don't usually heat the amp that much. I guess that in the case of AHB2 there's very little idle heat due to power supply rail switching.

 

Stereopile measured the thing. It measures better than most DACs

 

But how does it sound? I don't really care how great an amp measures if it doesn't sound great. My Vidar measures fairly well and sounds very good. But, my Pioneer M-22 measures better and sounds fantastic! How does the AHB-2 sound compared to the Vidar?

 

Some more measurements to self flagellate over... http://www.soundstagenetwork.com/in...hb2-stereo-mono-amplifier&catid=97&Itemid=154

p.s. I do have this amp, and I'm done looking for the time being

 

Ok, Chart 5A from the link provided:



That is looking very clean indeed, impressive. Is this a low feedback design?
As others note, measurements are well and all, but how it sounds in the intended system is the key point.

 

THX AAA feedforward design.

 

You guys are hilarious. I praised this thing months ago and no one gave a shit. If I only had headphones or normal speakers, I would have sold my Krell for this. It's a fantastic little amp that can be had for ~2k used. It actually has big boy sound. Really no brainer. A member here does have normal speakers and uses 2 of these in bridged mono. Again, a few of us praised this thing almost a year ago and no one gave a shit.

Who gives a shit if it's not Class A (unless running ESLs). It sounds damn good.

@cskippy, if you want that AHB2 to sound even better, upgrade your preamp.