Review and Measurements of Benchmark AHB2 Amp

[Roasty]

Hi all

First post here.. Wondering if I can get a quick opinion.

Was looking at the AHB2. My current setup (in my relatively small-ish bed room) is:

CXN v2 network streamer
Benchmark Dac 3b
Benchmark Hpa4 (for headphones, and as line ampifier for speaker listening)
Audiolab 6000a in power amp mode
B&W 606 bookshelves + Rel t7i subwoofer

I also have a pair of buchardt s400 speakers in the mail.

Would the ahb2 be alright or overkill in my situation? I don't find the audiolab lacking.. But then again I don't have anything else to compare it to. I find my current setup is a little cold/dry. Read some reviews saying the ahb2 adds a bit of meatiness and warmth (?).

Probably just an upgrade bug which is digging into the back of my mind..

 

[etc6849]

Custom windows PC.

What is the preamp/digital source in the top left--with the round (volume?) knob?

 

[RichB]

Hi all

First post here.. Wondering if I can get a quick opinion.

Was looking at the AHB2. My current setup (in my relatively small-ish bed room) is:

CXN v2 network streamer
Benchmark Dac 3b
Benchmark Hpa4 (for headphones, and as line ampifier for speaker listening)
Audiolab 6000a in power amp mode
B&W 606 bookshelves + Rel t7i subwoofer

I also have a pair of buchardt s400 speakers in the mail.

Would the ahb2 be alright or overkill in my situation? I don't find the audiolab lacking.. But then again I don't have anything else to compare it to. I find my current setup is a little cold/dry. Read some reviews saying the ahb2 adds a bit of meatiness and warmth (?).

Probably just an upgrade bug which is digging into the back of my mind..

I use an AHB2 in my game room drives the Revel M20's. The Oppo UDP-205 is the source component streaming from Roon.
I listen to this system mostly below 1 watt so low distortion is a benefit.

Will this improve your system? Perhaps not, but if you are into accuracy and reducing all levels of distortion and noise, this amp will do it.
It may even cure the upgrade bug for amplifiers. You can put that in the done pile

- Rich

 

[Roasty]

I use an AHB2 in my game room drives the Revel M20's. The Oppo UDP-205 is the source component streaming from Roon.
I listen to this system mostly below 1 watt so low distortion is a benefit.

Will this improve your system? Perhaps not, but if you are into accuracy and reducing all levels of distortion and noise, this amp will do it.
It may even cure the upgrade bug for amplifiers. You can put that in the done pile

- Rich

Thanks man. I'll look into the ahb2 but I can only get it new as second hand units are hard to come by where I'm at.

My other option is a used bel canto s300 which I can get for relatively cheap.

Seriously.. The upgrade bug is a real b*tch and is probably the source of many of my audio woes.

 

[blodsbror]

On a side note, has anyone used the AHB2 in a systems with KEF LS50's ?. I'm a little afraid that, the KEF's will sound a bit too bright. I'm also looking for a combined pre-amp/DAC, and was thinking of the Matrix Audio X-sabre Pro. But would be interested to hear, what others are using with the AHB2 and LS50's.

 

[anmpr1]

On a side note, has anyone used the AHB2 in a systems with KEF LS50's ?. I'm a little afraid that, the KEF's will sound a bit too bright. I'm also looking for a combined pre-amp/DAC, and was thinking of the Matrix Audio X-sabre Pro. But would be interested to hear, what others are using with the AHB2 and LS50's.

If I'm not mistaken, Benchmark offers a 30 day evaluation. Send for one, live with it a couple of weeks, and send it back if you don't like it.

 

[blodsbror]

If I'm not mistaken, Benchmark offers a 30 day evaluation. Send for one, live with it a couple of weeks, and send it back if you don't like it.

I live in Norway, with no local dealer as far as I'm aware. Unless that's a worldwide return service, then hence me asking for others experiences

 

[Sal1950]

It may even cure the upgrade bug for amplifiers. You can put that in the done pile

- Rich

Seriously.. The upgrade bug is a real b*tch and is probably the source of many of my audio woes.

Ya know, we all keep saying that, "the AHB2 will be end of the line in amps"
But truthfully, at some point there will be a AHB3 and AHB4 just like there was DAC1, 2 and 3, so far.
And you'll just have to get it. LOL

 

[digitalfrost]

On a side note, has anyone used the AHB2 in a systems with KEF LS50's ?. I'm a little afraid that, the KEF's will sound a bit too bright. I'm also looking for a combined pre-amp/DAC, and was thinking of the Matrix Audio X-sabre Pro. But would be interested to hear, what others are using with the AHB2 and LS50's.

I've used it with LS50. I have no problems with it being too bright. More detailed maybe, but not too bright. That said, I'm using DRC-FIR to correct the frequency response, and I prefer a downward tilt. In that regard, I might suffer less from the alleged metal brightness that some seem to attribute to the LS50. However, I've always been using DIR-FIR with every other amp, and I've always re-measured the setup when changing amps, so that shouldn't change anything. It's a good match IMHO.

 

[RichB]

Ya know, we all keep saying that, "the AHB2 will be end of the line in amps"
But truthfully, at some point there will be a AHB3 and AHB4 just like there was DAC1, 2 and 3, so far.
And you'll just have to get it. LOL

Absolutely true.
They could increase power and decrease output impedance and make them the size of a pack of cigarettes.

For DAC's make it a Roon endpoint and I'd have a look.

- Rich

 

[Sal1950]

Absolutely true.
They could increase power and decrease output impedance and make them the size of a pack of cigarettes.

For DAC's make it a Roon endpoint and I'd have a look.

- Rich

Plus even lower noise and distortion measurements.
Doesn't matter they won't sound any better, that point was passed decades ago.
Truth is truth, Just sayin ----------- LOL

 

[anmpr1]

They could increase power and decrease output impedance and make them the size of a pack of cigarettes.



- Rich

 

[RichB]

The gain specifications for the AHB2 are:
Input Sensitivity

• Low-Gain = 22 dBu (9.8 Vrms), Gain = 9.2 dB
• Mid-Gain = 14.2 dBu (4 Vrms), Gain = 17.0 dB
• High-Gain = 8.2 dBu (2 Vrms), Gain = 23 dB

How do I compute the voltage required by the preamplifier to achieve common voltages? For example, input voltage to achieve and output voltage at 2.83 volts?

- Rich

 

[digitalfrost]

For high gain: Should be 0.2v input for 2.83V output. http://www.sengpielaudio.com/calculator-amplification.htm. 2V input will be 28V output, which into 8ohms is 98W (http://www.sengpielaudio.com/calculator-ohm.htm) so it seems correct to me.

 

[DonH56]

Voltage gain = 20 * log10(Vout/Vin) thus Vout = Vin * 10^(gain/20). Power Pavg = Vrms^2 / R.

So at mid-gain 2 Vrms in will provide 2 Vrms * 10^(17/20) = 2 * 7.1 = 14.16 Vrms output or 25 W into 8 ohms (P = Vrms^2 / R).

HTH - Don

 

[DonH56]

It is a power amplifier; no remote, no volume control other than the gain settings. Volume is regulated by the upstream source (your preamp, processor, DAC, stand-alone volume control, etc.) Many power amplifiers eschew any sort of volume control in the amp itself. Since preamp/mixer levels are fairly well standardized most amps are designed to provide full output from typical consumer (e.g. ~2 Vrms) source levels. At least Benchmark provides gain control. Most home users will use high gain; pro setups medium or low.

HTH - Don

 

[digitalfrost]

Also would like to know what else is in the box. Only one power cord with US plug, power cords with European/UK plugs as well?

https://www.audiosciencereview.com/...ements-of-benchmark-ahb2-amp.7628/post-185307

You get the amp, a bit of printed paper and 1 power chord. Mine was Schuko/C13.

 

[PaulD]

Oh, thank you very much! So - no remote? How do you regulate the volume then?...

It's a power amp, the volume is regulated with the thing (preamp / DAC etc) before it... That is standard.

 

[Kal Rubinson]

There is no remote control with the AHB2 power amp, nor is one needed.

 

[RichB]

L

Thank you for this "amp 101"..

So do I understand it right that connecting a Chord Qutest DAC directly into this amp will render DAC's optical input useless since optical input has no volume control?

Thanks!

The AHB2 high, medium, and low gain settings can be used as rudimentary volume control, but I would not recommend it.

- Rich