Review and Measurements of Benchmark AHB2 Amp

[granosalis]

Thanks a lot darkless, expecially because you registered just to answer to my question. Tannoy are sensitive, but they whant lot of power to sounds at their best.

 

[RPG]

I received mine today. If you’re wondering about the silver face panel, the milling is just as good as on other high end silver units. The photos at Benchmark’s website make it look flat or featureless. It isn’t. If you prefer silver, go for it. It’s very good looking.

This isn’t a forum for subjective opinions, so I won’t talk about those...however, after two hours of classical music, I’m pretty certain I will be keeping it.

I got my AHB2 this morning and I'm absolutely certain I will be keeping it. Superb combo w/RME ADI2-DAC and Revel F-208's. First time I've had zero hiss/buzz out of my speakers w/no music playing. And the music.... :>) :>) :>)....

 

[Laserjock]

I got my AHB2 this morning and I'm absolutely certain I will be keeping it. Superb combo w/RME ADI2-DAC and Revel F-208's. First time I've had zero hiss/buzz out of my speakers w/no music playing. And the music.... :>) :>) :>)....

What have you used before ?

 

[direstraitsfan98]

Hi Giuseppe. This is also my first post as I just registered in order to reply to your question.

I happen to have a Benchmark AHB2 that until recently was used to power my Tannoy Canterbury GR speakers. It's a great combination, and I've never had the amp run out of steam on these speakers. Their sensitivity rating at 96 dB/W/m with a nominal impedance of 8 Ohm seems to be an easy load for the AHB2.

In short, If you're looking for a truly transparent power amp look no further. I tried but ultimately failed to consistently tell a difference between my Chord DAVE's analog output stage directly feeding my Tannoys vs having the AHB2 powering them. Obviously the dedicated amp has a lot more power than the DAC, so it's not a fair comparison.

I'm afraid I can't help you with your question regarding having an extra amp, but I can say that I've never been able to make the amp clip using the Tannoys. At a meet last year where I had taken the AHB2 with me, we used it to power a pair of bookshelf speakers with much lower sensitivity and we did manage to make it clip on those, although the volume level was higher than what I am comfortable listening to in my own room.

How do you hook up the dave to the speakers?

 

[RPG]

What have you used before ?

Had an LFD NCSE for about 7 yrs.....British boutique-y amp.

 

[darkless]

How do you hook up the dave to the speakers?

I soldered some RCA connectors to a pair of speaker cables I had lying around. It was a bit of a pain since the wire was thicker than what is normally used for RCA connectors.

 

[ArnoldWilliams]

I adore your material about photography, it is always so useful to me.

https://fixthephoto.com/vlog-video-editing

 

[Mikechw]

I am getting my 2nd Benchmark AHB2 today ...
Planning to use them in dual mono.. setup.

I toggled the MONO/STEREO switch at the back of my current stereo setup AHB2 and there are still sound coming out from both speakers.
I assumed they are outputing same left channel audio but one channel's phase is inverted.
Am I correct ??

 

[RichB]

I am getting my 2nd Benchmark AHB2 today ...
Planning to use them in dual mono.. setup.

I toggled the MONO/STEREO switch at the back of my current stereo setup AHB2 and there are still sound coming out from both speakers.
I assumed they are outputing same left channel audio but one channel's phase is inverted.
Am I correct ??

When you bridge the AHB2, you must also change the connections to the speaker to the center ones.
This is described in the manual.

- Rich

 

[Mikechw]

Thanks for your info..

Actually I am going to try bi-amp when I get my 2nd AHB2. (So no bridging yet)
I currently have one AHB2 and the 2nd one is coming this afternoon.
I am not using SpeakOn connectors.. My speakers are connected to the speaker binding posts. (CH1 and CH2 out)

 

[Laserjock]

Thanks for your info..

Actually I am going to try bi-amp when I get my 2nd AHB2. (So no bridging yet)
I currently have one AHB2 and the 2nd one is coming this afternoon.
I am not using SpeakOn connectors.. My speakers are connected to the speaker binding posts. (CH1 and CH2 out)

Don’t change the switch to mono until you use it as mono.

 

[Mikechw]

Don’t change the switch to mono until you use it as mono.

I have bought a pair of Y-Split XLR cables already. So the STEREO/MONO switch will stay STEREO...

Once, I was toggling the gain settings on the back of AHB2, but accidently toggled the Stereo/Mono switch.
And I found out that there are still audio coming out from both speakers. So just want to test out if SQ would be better without the Y-split cables..

 

[JimB]

Don’t change the switch to mono until you use it as mono.

Right. To get two separate channels with the same signal, @Mikechw needs to keep the amp in stereo mode, and use a splitter cable to provide the same input to both channels.

 

[Laserjock]

@Mikechw try the biamp but I would bet on running them mono to be the way to go.

Edit: or buy two more and truly biamp both with dual monos on both speakers...

 

[cjm2077]

Thanks for your info..

Actually I am going to try bi-amp when I get my 2nd AHB2. (So no bridging yet)
I currently have one AHB2 and the 2nd one is coming this afternoon.
I am not using SpeakOn connectors.. My speakers are connected to the speaker binding posts. (CH1 and CH2 out)

So what effect are you hoping to get by bi-amping your speakers?

 

[RPG]

Congratulations.
Great setup. Would have been nice to have seen photos of it in this thread:
https://www.audiosciencereview.com/...-kit-we-bought-our-current-setups.564/page-13

Thank you. I'll see what I can do about some photos.

 

[Mikechw]

2x AHB2 hooked up..

 

[Mikechw]

So what effect are you hoping to get by bi-amping your speakers?

I used to have a pair of DIY class D (Tripath based) that power my pair of Pioneer's. One of them was damaged when I was tinkering with the circuit.

I switched to Benchmark AHB2 last year after reading review from this forum. Budget was tight and I only bought one AHB2.
Now I have a pair to drive my speakers... I am doing vertical bi-amp.

First Impression is that I get better imaging. Bass is tighter.. Treble is clearer. I think its worth the upgrade..
( I am using 17db gain setting)

Now I also have the option to go bridging too..
AHB2's max gain is 23db and after bridging its 29db.

I have an integrated Accuphase E-480 which has gain fixed at 28db. (I think 1db is not much of a difference.)
I may try mix and match and use that to bi-amp with 2x bridged AHB2.

 

[tuga]

Actually I am going to try bi-amp when I get my 2nd AHB2.

What for if I may ask?

 

[cjm2077]

I used to have a pair of DIY class D (Tripath based) that power my pair of Pioneer's. One of them was damaged when I was tinkering with the circuit.

I switched to Benchmark AHB2 last year after reading review from this forum. Budget was tight and I only bought one AHB2.
Now I have a pair to drive my speakers... I am doing vertical bi-amp.

First Impression is that I get better imaging. Bass is tighter.. Treble is clearer. I think its worth the upgrade..
( I am using 17db gain setting)

Now I also have the option to go bridging too..
AHB2's max gain is 23db and after bridging its 29db.

I have an integrated Accuphase E-480 which has gain fixed at 28db. (I think 1db is not much of a difference.)
I may try mix and match and use that to bi-amp with 2x bridged AHB2.

If you're passively bi-amping the speakers (still using the crossover in the speakers), then there really isn't an advantage compared to using the same amp bridged. In fact, the bridged amp should perform better because more power will be available to the woofer, which is the part that will probably need it. If you look at active speakers the woofer section always has the biggest amp, and that is for good reason. And with the amplifiers getting the full range of the input signal, they're still going to have the same levels of intermodulation and other forms of distortion. If you do the crossover before the amps, you can actually improve those distortions. If you can bridge channels instead of bi-amping (which you can with the AHB2), I would always reccomend that.