Benchmark AHP2 - wow! a reference to all power amps?

[krolikgena]

www.benchmarkmedia.com/power-amplifier/ahb2

:wave:

 

[ID.]

www.benchmarkmedia.com/power-amplifier/ahb2

:wave:

I like the look of it matched with the DAC2. I may have overlooked it, but I wonder what the specs are.

Edit: Never mind

http://www.benchmarkmedia.com/power-amplifier/ahb2/specifications

 

[drummerman]

No more response?

A new product from a proven and accomplished manufacturer.

Looks interesting but what about price?

regards

 

[krolikgena]

"The price of the Benchmark Media Systems AHB2 is projected to be under $3000 when it's released in December of this year" according to SoundStage!Global

 

[davedotco]

"The price of the Benchmark Media Systems AHB2 is projected to be under $3000 when it's released in December of this year" according to SoundStage!Global

Thats a heck of a lot of money for something that won't sound like anything at all...... :?

 

[shooter]

Interesting thinking from Benchmark but do you really need an amp with a noise floor 30db less than other amps when our listening rooms have a noise floor of 30 - 40 dbs anyway?

Also as i understand it the need for speakers to have extended frequency response as HD recordings create ringing out of the audio band which come in to the listening band if the speakers cant deal with it, but amps?

 

[andyjm]

Also as i understand it the need for speakers to have extended frequency response as HD recordings create ringing out of the audio band which come in to the listening band if the speakers cant deal with it, but amps?

As you apparently understand this, perhaps you could explain it for the rest of us?

 

[shooter]

Easier to link it, friday night = lazy night :beer:

http://www.whathifi.com/forum/computer-based-media/any-need-for-high-sampling-rates

 

[andyjm]

Couldnt find anything in that thread about out of band ringing, or speakers producing sub-harmonics. Probably best to explain it tomorrow. Enjoy your Friday night.

 

[shooter]

No need it's in the links at the start of the thread not the thread itself though still a good read.

 

[andyjm]

No need it's in the links at the start of the thread not the thread itself though still a good read.

Yep, been though the links. One doesn't work and the other two don't seem to make reference to speakers producing sub-harmonics, or out of band ringing with high sample rate audio.

What do you understand to be the effects?

 

[JohnSiau]

For those of you who are curious about the Benchmark AHB2 here is a summary of the design gaols and the unique features of the amplifier:

It was my goal to create a power amplifier that matched the performance of the DAC2 D/A converter. After all, the performance of the D/A converter is only useful if it can be delivered by the downstream power amplifier.

In many ways, the AHB2 is a radical departure from conventional class AB amplifier design:

1) Low gain (9 dB) - allows +22 dBu input at amplifier clip - essential for low noise

2) Patented feed-forward error correction - virtually eliminates crossover distortion

3) Feed-forward design makes bias currents unnecessary, and non-critical - class B operation is possible with very low distortion

4) Multiple output stages run in parallel to eliminate crossover distortion - one output stage is active while another is in the crossover region

5) Class AB output stage uses very low bias current

6) Due to low bias currents, idle power consumption is only 20 W

7) Feed-forward design makes class H or G operation possible - no rise in distortion at class H or G switch point

8 ) Class H (or G) rail switching at a 1/3 power threshold

9) Tightly regulated power supply

10) High-bandwidth control loop on switch-mode power supply responds to amplifier loading over the entire audio band, and at ultrasonic frequencies

11) Amplifier does not rely on capacitive energy storage

12) Switch-mode power supply eliminates AC line magnetic interference to levels that are not possible with a linear power
supply

13) >200 kHz bandwidth to achieve excellent inter-channel phase at 20 kHz.

14) < 0.1 Hz low frequency cutoff to minimize low-frequency phase shift

15) Feed-forward design improves damping factor

The AHB2 design was optimized for low distortion and low noise. It was not optimized for the highest possible efficiency that can be achieved with this new topology. Nevertheless the AHB2 is much more efficient than a conventional class AB design. Peak power does not vary with AC line voltage (due to regulated supply). Power drawn on one channel does not influence the power available from the other
channel.

The AHB2 is a linear amplifier, it is not a switcher. For this reason, it produces very little out-of-band noise. A-weighted noise is only 2 dB
less than noise measured over an 80 kHz bandwidth. This was an important design goal because ultrasonic noise can be folded into the audio band by non-linearities in speaker transducers.

THD is better than -120 dB (0.0001 %)

John Siau

VP

Benchmark Media Systems, Inc

 

[oldric_naubhoff]

For those of you who are curious about the Benchmark AHB2 here is a summary of the design gaols and the unique features of the amplifier:

It was my goal to create a power amplifier that matched the performance of the DAC2 D/A converter. After all, the performance of the D/A converter is only useful if it can be delivered by the downstream power amplifier.

In many ways, the AHB2 is a radical departure from conventional class AB amplifier design:

1) Low gain (9 dB) - allows +22 dBu input at amplifier clip - essential for low noise

2) Patented feed-forward error correction - virtually eliminates crossover distortion

3) Feed-forward design makes bias currents unnecessary, and non-critical - class B operation is possible with very low distortion

4) Multiple output stages run in parallel to eliminate crossover distortion - one output stage is active while another is in the crossover region

5) Class AB output stage uses very low bias current

6) Due to low bias currents, idle power consumption is only 20 W

7) Feed-forward design makes class H or G operation possible - no rise in distortion at class H or G switch point

8 ) Class H (or G) rail switching at a 1/3 power threshold

9) Tightly regulated power supply

10) High-bandwidth control loop on switch-mode power supply responds to amplifier loading over the entire audio band, and at ultrasonic frequencies

11) Amplifier does not rely on capacitive energy storage

12) Switch-mode power supply eliminates AC line magnetic interference to levels that are not possible with a linear power
supply

13) >200 kHz bandwidth to achieve excellent inter-channel phase at 20 kHz.

14) < 0.1 Hz low frequency cutoff to minimize low-frequency phase shift

15) Feed-forward design improves damping factor

The AHB2 design was optimized for low distortion and low noise. It was not optimized for the highest possible efficiency that can be achieved with this new topology. Nevertheless the AHB2 is much more efficient than a conventional class AB design. Peak power does not vary with AC line voltage (due to regulated supply). Power drawn on one channel does not influence the power available from the other
channel.

The AHB2 is a linear amplifier, it is not a switcher. For this reason, it produces very little out-of-band noise. A-weighted noise is only 2 dB
less than noise measured over an 80 kHz bandwidth. This was an important design goal because ultrasonic noise can be folded into the audio band by non-linearities in speaker transducers.

THD is better than -120 dB (0.0001 %)

John Siau

VP

Benchmark Media Systems, Inc

hi John and welcome to the forum.

congratulation on conceiving such a marvel of an amp at such an affordable price point. so far the most quiet amps I could find were in the region of -118dB SNR referenced to full output. pretty low already but nowhere near as low as state of the art DACs available ATM. congratulations for finding a way to push the boundaries even further!

one more question from me. how is the amp performing into "electrostatic" loads, i.e. 2 Ohms and below + high phase shift. from your website I can see the amp is only rated down to 4 Ohms. thanks in advance for your reply.

 

[BigH]

Sorry but what is the UK price?