Benchmark AHB2 Review (Updated Measurements)

[Chester]

Just had a strange occurance with one of my AHB2’s. I couldn’t see anything in the manual about it.

Both channels are showing as muted, as if it was in the process of turning off, except it just stayed like that. If I push the power button it just immediately goes back to the usual ‘on’ state. If I push the button again, it happens again….. Both channels mute but it does not power down.

Does anyone have any ideas?

 

[RichB]

Just had a strange occurance with one of my AHB2’s. I couldn’t see anything in the manual about it.

Both channels are showing as muted, as if it was in the process of turning off, except it just stayed like that. If I push the power button it just immediately goes back to the usual ‘on’ state. If I push the button again, it happens again….. Both channels mute but it does not power down.

Does anyone have any ideas?

I would contact Benchmark support; they will help you out.

- Rich

 

[enricoclaudio]

Just had a strange occurance with one of my AHB2’s. I couldn’t see anything in the manual about it.

Both channels are showing as muted, as if it was in the process of turning off, except it just stayed like that. If I push the power button it just immediately goes back to the usual ‘on’ state. If I push the button again, it happens again….. Both channels mute but it does not power down.

Does anyone have any ideas?

Check page 15 on the AHB2 user manual. Yours went into protection mode.

https://cdn.shopify.com/s/files/1/0321/7609/files/AHB2_Manual_-_Rev_H.pdf?v=1602610101

 

[Chester]

Check page 15 on the AHB2 user manual. Yours went into protection mode.

https://cdn.shopify.com/s/files/1/0321/7609/files/AHB2_Manual_-_Rev_H.pdf?v=1602610101

Thanks, but none of these match the behaviour I experienced.

 

[Pearljam5000]

Just had a strange occurance with one of my AHB2’s. I couldn’t see anything in the manual about it.

Both channels are showing as muted, as if it was in the process of turning off, except it just stayed like that. If I push the power button it just immediately goes back to the usual ‘on’ state. If I push the button again, it happens again….. Both channels mute but it does not power down.

Does anyone have any ideas?

If there's some sort of factory reset maybe try that
And updating the firmware

 

[gfinlays]

Just had a strange occurance with one of my AHB2’s. I couldn’t see anything in the manual about it.

Both channels are showing as muted, as if it was in the process of turning off, except it just stayed like that. If I push the power button it just immediately goes back to the usual ‘on’ state. If I push the button again, it happens again….. Both channels mute but it does not power down.

Does anyone have any ideas?

Is it in Auto-on mode?

Hold the power button down for 3 seconds, once the clip lights go off, release and it should turn on and off as normal.

 

[Chester]

Is it in Auto-on mode?
View attachment 406119
Hold the power button down for 3 seconds, once the clip lights go off, release and it should turn on and off as normal.

Thank you @gfinlays I believe this is the likely cause. No idea how it entered that mode but holding the power button for a few seconds does seem to have resolved the issue.

 

[digitalfrost]

I just noticed that the AHB2 Logo somehow had it's H gone missing

 

[gfinlays]

The logo and lettering on the AHB2 are painted on, I think. They're relatively easy to damage.

 

[Billy Budapest]

Too bad they aren’t decals. Ayre products were infamous for decals rubbing off. Ayre customer service would send you decals if you emailed them a picture of the damage and your serial number. I remember it being a pretty easy fix— I only had to replace the “e” as seen below:

 

[Kal Rubinson]

Can I put them on my Benchmarks?

 

[enricoclaudio]

Out of curiosity, how you get to rubbing off a logo where there is no button to press in behind it? My HPA4 logo is on the touch screen so I’m safe on that part!!

 

[Billy Budapest]

Can I put them on my Benchmarks?

LOL! If Ayre would send them to you, I am sure you could put them on whatever you wanted!

 

[RB Dennis 57]

I use locking ones.

Here are the Specifications for the Amplifier. As expected they are detailed and lengthy:

Manufacturer Specifications:

Continuous Average Output Power​

< 0.0003 % THD+N at full rated power, 20 Hz to 20 kHz

• 100 Watts per channel into 8 Ohms, both channels driven
• 130 Watts per channel into 6 Ohms, both channels driven
• 190 Watts per channel into 4 Ohms, both channels driven
• 240 Watts per channel into 3 Ohms, both channels driven
• 200 Watts into 16 Ohms, bridged mono
• 380 Watts into 8 Ohms, bridged mono
• 480 Watts into 6 Ohms, bridged mono

All speakers have variations in input impedance. Select loads based on nominal impedances not minimum impedances. The AHB2 is stable into all loads. The AHB2 is conservatively rated at an output level where THD+N is < 0.0003 % instead of the more typical 1% THD+N. Power at 1% THD will be higher.

Output Voltage Into Various Load Impedances​

< 0.0003 % THD+N at the following output voltages and load impedances, 20 Hz to 20 kHz

• 29.03 dBV, 31.25 dBu, 28.28 Vrms into 8 Ohms, both channels driven
• 28.92 dBV, 31.14 dBu, 27.93 Vrms into 6 Ohms, both channels driven
• 28.81 dBV, 31.03 dBu, 27.57 Vrms into 4 Ohms, both channels driven
• 28.57 dBV, 30.79 dBu, 26.83 Vrms into 3 Ohms, both channels driven
• 27.14 dBV, 29.36 dBu, 22.76 Vrms into 2 Ohms, both channels driven
• 35.05 dBV, 37.27 dBu, 56.57 Vrms into 16 Ohms, bridged mono
• 34.83 dBV, 37.05 dBu, 55.14 Vrms into 8 Ohms, bridged mono
• 34.59 dBV, 36.81 dBu, 53.67 Vrms into 6 Ohms, bridged mono
• 33.16 dBV, 35.38 dBu, 45.52 Vrms into 4 Ohms, bridged mono

Use dBV to calculate the peak SPL from your speaker/amplifier combination. Use the following formula: Amplifier output voltage in dBV + speaker sensitivity at 2.83V - 9 dB. Example: (29.03 dBV at 8 Ohms) + (90 dB SPL @ 2.83V 1m) - 9 dB = 110 dB SPL at 1 meter

SNR & Dynamic Range​

Rated output relative to output noise, inputs shorted

• 132 dB A-weighted, Stereo Mode
• 135 dB A-weighted, Mono Mode
• 130 dB Unweighted, 20 Hz to 20 kHz, Stereo Mode
• 133 dB Unweighted, 20 Hz to 20 kHz, Mono Mode

Noise Voltage​

Output noise voltage, A-weighted, inputs shorted

• -103 dBV, -101 dBu, 7.1 uVrms, Stereo Mode
• -100 dBV, -98 dBu, 9.8 uVrms, Mono Mode

Use dBV to calculate the SPL of the noise produced by your speaker/amplifier combination. Use the following formula: Amplifier output noise voltage in dBV + speaker sensitivity at 2.83V - 9 dB. Example: Mono mode driving very high efficiency speakers: (-100 dBV) + (104 dB SPL @ 2.83V 1m) - 9 dB = -5 dB SPL at 1 meter. This means that the system noise will be 5 dB below the threshold of hearing when driving speakers with a very high 104 dB efficiency.

Noise Relative to 2.83 Vrms​

Output noise relative to 2.83 Vrms, A-weighted, inputs shorted

• -112 dB, Stereo Mode
• -109 dB, Mono Mode

THD+N​

1 kHz, 80 kHz LPF, at full rated output into any rated load

• < -118 dB (< 0.00013%), Stereo Mode
• < -118 dB (< 0.00013%), Mono Mode

THD​

1 kHz, 20 kHz LPF, at full rated output into any rated load

• < -119 dB (< 0.00011%), Stereo Mode
• < -120 dB (< 0.00010%), Mono Mode

Crosstalk​

• Better than -115 dB at 1 kHz
• Better than -92 dB at 20 kHz

Frequency Response​

• Better than 0.1 Hz to 200 kHz, +0/-3 dB
• -0.01 dB at 20 Hz, -0.17 dB at 20 kHz, 8-Ohm Load
• -0.23 dB at 20 Hz, -0.32 dB at 20 kHz, 4-Ohm Load

Damping Factor​

• 350 at 20 Hz, 8-Ohms
• 254 at 1 kHz, 8-Ohms
• 34 at 20 kHz, 8-Ohms
• 7 at 200 kHz, 8-Ohms

Maximum Audio Output Current​

• 29 A peak, per channel, both channels driven

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
• Use Mid-Gain or High-Gain settings for unbalanced inputs
• Unbalanced inputs require RCA to XLRM adapter cables

Input Impedance​

• 50 k Ohms, normal mode
• 1 M Ohm, common mode

Input CMRR​

• 80 dB at 20 Hz, typical
• 80 dB at 1 kHz, typical
• 65 dB at 20 kHz, typical

Trigger I/O​

• 12 VDC 200 mA current-limited output to trigger turn-on of remote devices
• DC input for slaving to remote devices
• Input responds to 3.3 V logic and higher, VIL = 1.26 V, VIH = 2.7 V
• Absolute maximum input voltage = 30 VDC
• Absolute minimum input voltage = -0.3 VDC
• Input Impedance = 20 k Ohms

Protection Circuits​

• Fully Electronic, No Relays
• Mute Sequencing
• Distortion Detection
• Short Circuit Detection
• Over Current Detection
• Over Temperature Detection
• SOA Detection (Output device safe operating area)

Dimensions​

Non-rack-mount version:​

• 11.04" W x 3.88" H x 9.34 " D - Including feet and binding posts
• 11.04" W x 3.47" H x 8.33 " D - Excluding feet and connectors
• Faceplate height is 2RU

Rack-mount version:​

• 19.00" W x 3.88" H x 10.62 " D - Including binding posts, handles and removable feet
• 19.00" W x 3.47" H x 8.33 " D - Excluding feet and connectors
• 9.09" rack depth, including binding posts, excluding cables
• 11" rack depth, including cables
• Faceplate height is 2RU

Weight​

• 12.5 lbs., 16 lbs. shipping - Non-rack-mount version
• 13.5 lbs., 17 lbs. shipping - Rack-mount version

AC Input​

• Auto-ranging AC Input
• 100 to 120 VAC +/- 10%, 8 Amps, 50 - 60 Hz
• 220 to 240 VAC +/- 10%, 8 Amps, 50 - 60 Hz
• Idle Power Consumption = 20 W
• Standby Power Consumption < 0.5 W

I acquired Benchmarks SpeakerON Cables with locking bananas into the speakers. They are modestly priced compared to high end cables.

 

[HappyCow]

I acquired Benchmarks SpeakerON Cables with locking bananas into the speakers. They are modestly priced compared to high end cables.

I also got these. And now I wish all amps had SpeakOn connectors

 

[Giacomo]

I also got these. And now I wish all amps had SpeakOn connectors

In my system the are a little top bright.

 

[Julf]

In my system the are a little top bright.

Are you saying your cables and/or connectors affect the frequency response of your system?

 

[Giacomo]

Are you saying your cables and/or connectors affect the frequency response of your system?

No comment

 

[Julf]

No comment

Yes, that is probably the wise answer.

 

[xaxxon]

I hope this will not get used as evidence for expensive audiophile connectors.

speakon isn't expensive

What would it look like at 4ohm?

I run mine bridged into 4 ohm and thump that bass. They sound great.

I spoke to benchmark about it on the phone and they just said they weren't rated for that continual heat loading and could eventually protect so they didn't list it. They said it was perfectly safe.

I have put a stereo ahb2 into protect on 4 ohm which is why I bought 2 more to have 5 instead of 3 for my HT setup.