Review and Measurements of Benchmark AHB2 Amp

[josh358]

Someone should sell a big, impressive faceplate with backlit meters in it. Made out of that plated plastic that has the appearance of brushed aluminum. And include some Velcro so you can stick it to the front of your AHB2.

 

[Kal Rubinson]

Someone should sell a big, impressive faceplate with backlit meters in it. Made out of that plated plastic that has the appearance of brushed aluminum. And include some Velcro so you can stick it to the front of your AHB2.

What happened to all those companies that plopped Oppo players into fancy packages? They already know how to do these things.

 

[restorer-john]

so where does Benchmark go with this design from here? What is next to improve it?

Make a full size HiFi and/or 19" component version with a full width front panel and call it the AHB-4.

It is a four channel unit (great for bi-ampling, HT etc), which can be bridged into 2 channel. Same specs as two BTL mono AHB-2s, but only costs around US$5k. Lots of cost savings in one case, but no compromises in performance. It covers the 2 channel guys who say they want "more power" than the standard AHB-2 and feel like they shouldn't need to buy two to get the power they want.

Tweak the protection if it needs it for full rated power at 4R in BTL (2R per channel effectively) or not, if it's good already. Either use two of the standard SMPSs or a dedicated double sized one to save some internal space and cost.

(@John_Siau I'll have an AHB-2 or a prototype AHB-4 for that idea )

 

[ex audiophile]

View attachment 83259View attachment 83259

Our chickens love their AHBs and got spoiled by the great sound. In fact they threatened to withhold eggs if they didn't get Atmos in the coop; we compromised at 5.1

 

[josh358]

What happened to all those companies that plopped Oppo players into fancy packages? They already know how to do these things.

Who was it who got in trouble with that? I'm getting old.

 

[josh358]

Seriously, an AHB with twice the power would be nice.

 

[waynel]

Seriously, an AHB with twice the power would be nice.

How about roughly 4 times the power but only twice the cost? And make them mono blocks too!

 

[vavan]

no love for integrated?

 

[RichB]

no love for integrated?

Benchmark DAC3 can be used with optional LA4 an there you go. They stack nicely.
I prefer to keep my amps separate.

- Rich

 

[Billy Budapest]

What happened to all those companies that plopped Oppo players into fancy packages? They already know how to do these things.

Ah, yes, the LexiCON!

 

[sepp2gl]

@amirm:
The AHB2 looks like a perfect "top-level benchmark" for my own project indeed.
Did Benchmark publish any AHS2 schematics and BOM (besides publication in the patents)?

Apparingly AHS2 has a integrated DC/DC power supply at the motherboard together with both Amps.
I would be highly interested in the schematics of the amp.

 

[Billy Budapest]

Ah, yes, the LexiCON!

The LexiCON exposed:

https://www.audioholics.com/blu-ray...-ray-oppo-clone/oppo-inside-lexicon-outside-1

Lexicon’s response:

https://www.audioholics.com/blu-ray...lexicon-bd-30-blu-ray-oppo-clone/oppo-lexicon

And here is a reviewer that seemed to have been conned:

https://hometheaterreview.com/lexicon-bd-30-universal-blu-ray-player-reviewed/

 

[Jukebox]

I was running a single AHB2 in stereo mode with a pair of Revel 126be bookshelf speakers and a pair of Fathom 12 inch subs in a medium size room. When I ran ARC (STR preamp) it would set the speaker levels at +12 (max). I repeated this several times. I recently purchased a second AHB2 and running them in bridged mode the ARC program set the speakers at 0 and +2. The superficial explanation is more power from the amps but I'm sure there's more to it than that. In any case I'm delighted with the amps and the Benchmark cables are beautifully built.

How do you find the combo 126BE + AHB2? They are both on my shortlist. It is a must to add a second amp?

 

[RichB]

How do you find the combo 126BE + AHB2? They are both on my shortlist. It is a must to add a second amp?

I use a single AHB2 to drive the 126Bes used with Martin Logan Grotto i sub. It sounds great and I do not clip at mid sensitivity to match the Oppo UPD-205 4 volt output.

When bridged the gain (sensitivity) is increased by 6 dB which may account for the issue reported by Bombadil.

- Rich

 

[ex audiophile]

How do you find the combo 126BE + AHB2? They are both on my shortlist. It is a must to add a second amp?

Without the subs I found the combination sounded very good and for jazz it would be terrific, plenty of output for a medium size room. The subs of course added a wonderful "floor" to the sound and was a big improvement for the type of music I listen to. My thought would be to buy one AHB2 and see how it goes, more than likely it will be sufficient. I suspect many "second amps" are purchased more out of desire than need lol.
If I were to do it again I'd get the 226be rather than the bookshelfs.

 

[Jukebox]

Without the subs I found the combination sounded very good and for jazz it would be terrific, plenty of output for a medium size room. The subs of course added a wonderful "floor" to the sound and was a big improvement for the type of music I listen to. My thought would be to buy one AHB2 and see how it goes, more than likely it will be sufficient. I suspect many "second amps" are purchased more out of desire than need lol.
If I were to do it again I'd get the 226be rather than the bookshelfs.

Thanks for your insights! I do prefer Jazz, Acoustical but also listen to just about everything else. I have dual SVS SB3000 so no bass problem. Yes the 226Be looks the real deal but so much expensive and it's strange how intimate and revealing a truly good 2 way bookshelf can sound in a medium room.
Also I suspect the same about dual AHB2; no need but why not?
Will have to think about.
Thanks again!

 

[Jukebox]

I use a single AHB2 to drive the 126Bes used with Martin Logan Grotto i sub. It sounds great and I do not clip at mid sensitivity to match the Oppo UPD-205 4 volt output.

When bridged the gain (sensitivity) is increased by 6 dB which may account for the issue reported by Bombadil.

- Rich

Thanks for sharing! For sure I will try one and add a second down the road if I feel the need....probably not

 

[bern2a]

Hi,

My name is Bernard and I am from Sydney, Australia. I have read all 99 pages on the Benchmark AHB2 discussion and yet I could not find any discussions of the Magnepan 20.7 being driven by the Benchmark.
Does the Benchmark have sufficient power to drive the Magnepans?

Thanking you in anticipation.

Regards
Bernard

 

[anmpr1]

Does the Benchmark have sufficient power to drive the Magnepans?

Too many variables to say yes, or no. That said, Magneplanar 20.7 are 4 ohm with a rated sensitivity of 86dB (500 Hz) at one meter. So a single AHB will offer you almost 200 watts/ch, sans any appreciable distortion, before it runs out of steam. Two bridged AHB2 will give you 500 watts a channel.

You have to ask yourself, how loud do you want it to be at your normal listening level? Are you using a powered sub, which should relieve the amp of its work at the low end.

Below is one of the dedicated ASR Magnepan threads that is worth reviewing.

https://www.audiosciencereview.com/forum/index.php?threads/no-love-for-magnepan.10233/

 

[witwald]

I have read all 99 pages on the Benchmark AHB2 discussion and yet I could not find any discussions of the Magnepan 20.7 being driven by the Benchmark. Does the Benchmark have sufficient power to drive the Magnepans?

From the Magnepan Magneplanar 20.7 loudspeaker Lab Report, it would seem that these loudspeakers have a very low voltage sensitivity of about 80 dB SPL/1m/2.83Vrms. Although they are a nominal 4-ohm load, they were measured to have quite low impedance dips of 2.0 ohms at 318 Hz, 2.5 ohms at 450 Hz, and 2.0 ohms at 646 Hz. As the spectrum of music typically contains quite a bit of energy at those sorts of frequencies, it will require any amplifier to deliver a lot power there. Conservatively speaking, the AHB2 can deliver about 185 WRMS into a 4-ohm load, so it will probably do a reasonable job of driving these speakers to moderate in-room listening levels.