The SNR and THD performance of the AHB2 put this amplifier in a class by itself. Virtually Noise Free The AHB2 delivers a SNR that exceeds 132 dB A-weighted. This makes the AHB2 15 to 30 dB quieter than most top-quality power amplifiers. 132 dB is approximately equivalent to the noise performance of a perfect 22-bit digital system.
This symbol alerts the user that the product can only be used safely at altitudes lower than 2,000 meters. This symbol alerts the user that the product can only be used safely in non-tropical climates. AHB2 Instruction Manual Rev F Page 4...
Opening the unit will void the warranty. 12. Certain parts are safety related, or are required to meet certain regulations. All parts must be replaced with exact replacements unless written approval is granted by Benchmark. Unauthorized substitutions and modifications can create unsafe or non-compliant operating conditions and will void the warranty.
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Always replace both fuses at the same time. Operating Environment Warnings This product can only be used safely at altitudes lower than 2,000 meters. This product can only be used safely in non-tropical climates. AHB2 Instruction Manual Rev F Page 6...
Set this switch to STEREO if the AHB2 is driving a stereo pair of speakers. Set this switch to STEREO if the AHB2 is driving two channels of a multi-channel system. Set this switch to STEREO if the AHB2 is driving a biamped two-way speaker.
Please note that unbalanced sources will limit the overall performance of the playback system. This is not due to any limitations in the AHB2. It is due to the noise limitations of unbalanced output drive stages. High-level balanced interconnects are required in low-noise systems. We highly recommend balanced interconnects.
Both On During Start Up or Shut Down = Normal, Audio is Muted Both On = PROTECT Mode, a Fault has Occurred, Audio is Muted Note: Audio will automatically mute on startup and shutdown to protect the speakers and eliminate unwanted transients. AHB2 Instruction Manual Rev F Page 11...
Benchmark has reinvented the 12 volt trigger by adding bidirectional signaling. The trigger connection on the AHB2 can be used as an input, an output, or both. It is compatible with any common 12 volt trigger input or output. The 12V TRIGGER can be used to turn the AHB2 power amplifier on or off automatically in sequence with other audio system components.
Rack Mount Option Rack Mounting Instructions The AHB2 runs very cool when idle and runs very cool under most load conditions. However, it can produce significant heat when heavily loaded. Make sure the rack is adequately ventilated. Make sure the side heat sinks have an unobstructed air flow.
Fault Protection Circuitry The AHB2 is designed to detect overloads, short circuits, clipping, excessive temperatures, high DC offsets, and low AC input voltages. When a potentially-damaging fault occurs, the amplifier enters a special "PROTECT" mode to prevent damage. The amplifier has a comprehensive set of fault-detection circuits that will activate the PROTECT mode to protect against damage to the amplifier or speakers.
Channel 1 - Over-Current Fault Channel 2 - Over-Current Fault Chan. 1&2 - Over-Current Fault FLASH Channel 1 over temperature FLASH Channel 2 over temperature FLASH Power Supply fault or loss of AC SOA Fault AHB2 Instruction Manual Rev F Page 15...
Check for shorted speaker cables Check the position of the SENSITIVITY switch Move the sensitivity switch down one or two positions if necessary Turn down the audio source Restart the amplifier AHB2 Instruction Manual Rev F Page 16...
In STEREO mode, at full output, the 18 Amp limit can be reached if the load impedance dips below about 2 Ohms. In MONO mode, at full output, the 18 Ampere limit can be reached if the load impedance dips below about 4 Ohms. AHB2 Instruction Manual Rev F Page 17...
Make sure the nominal STEREO load impedance is 3 Ohms or higher Make sure the nominal Bridged MONO load impedance is 6 Ohms or higher Turn down the audio source Restart the amplifier AHB2 Instruction Manual Rev F Page 18...
Make sure the nominal Bridged MONO load impedance is 6 Ohms or higher Maintain adequate clearance around heat sinks Allow time for the amplifier to cool Turn down the audio source Restart the amplifier AHB2 Instruction Manual Rev F Page 19...
Make sure the nominal Bridged MONO load impedance is 6 Ohms or higher Maintain adequate clearance around heat sinks If unit is hot, allow time to cool Turn down the audio source Restart the amplifier AHB2 Instruction Manual Rev F Page 20...
34 at 20 kHz, 8-Ohms 7 at 200 kHz, 8-Ohms Environmental 0° C to 50° C (32° F to 122° F) Ambient Temperature Up to 80% Humidity - Non-condensing AHB2 Instruction Manual Rev F Page 22...
THD is shown on the left-hand scale. The stair steps are caused by the THD within the AP2722. This stair stepping demonstrates that the AHB2 is at or below the measurement limits of the AP2722 test set, even when the AHB2 is driving a heavy load.
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Figure 2 – THD vs. Output Power - 8-Ohm Load This plot shows the THD of the AHB2 with an 8-Ohm load. Note that the results are almost identical to those shown in Figure 1 (with a 4-Ohm load). Together, these two plots demonstrate that the THD performance of the AHB2 does not change with load.
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Figure 3 – THD vs. Output Power, Bridged Mono - 8-Ohm Load compared to No-Load This plot also shows that the THD produced by the AHB2 does not increase with loading. The red trace is the no-load THD performance in bridged mono mode. The green trace is the THD performance while driving an 8-Ohm load in bridged mono mode.
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Comment Cursor1 Cursor2 Solid Anlr.Ratio Left *350.4 X/Y *254.1 X/Y Damping_Factor_8Ohm.at27 Figure 4 – Damping Factor - 8-Ohm Load This plot shows that the AHB2 provides excellent damping to keep speakers tightly controlled. AHB2 Instruction Manual Rev F Page 28...
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Figure 5 – FFT at 320W, 1 kHz, 8-Ohms Bridged Mono This FFT plot shows the spectral purity of the AHB2. The green trace is the no-load performance. The red trace is the performance at 320 W. Both are nearly identical. The 1 kHz fundamental has been removed with a notch filter to improve the resolution of the AP2722 test set.
(European Union) directive 2002/95/EC, or, RoHS (Restrictions of Hazardous Substances). As of July 01, 2006, All Benchmark Media Systems, Inc. products placed on the European Union market are compliant (containing quantity limit weight less than or equal to 0.1% (1000 ppm) of any homogeneous Lead (Pb), Mercury (Hg), Hexavalent Chromium (Cr VI), and flame retardant Polybrominated Biphenyls (PBB) or Polybrominated Diphenyl Ethers (PBDE)).
In the event of failure of a product under this warranty, Benchmark Media Systems, Inc. will repair, at no charge, the product returned to its factory. Benchmark Media Systems, Inc. may, at its option, replace the product in lieu of repair.
Benchmark Extended Warranty Options The Benchmark Extended 5-Year Warranty * Benchmark Media Systems, Inc. optionally extends the standard 1-year warranty to a period of five years from the date of delivery. *For the extended warranty to become effective, the original purchaser must register the product at the time of purchase either by way of the enclosed registration card or through the product registration section of the Benchmark Media Systems, Inc.
Ce symbole avertit l' utilisateur que le produit ne peut être utilisé en toute sécurité à des altitudes inférieures à 2000 mètres. Ce symbole avertit l' utilisateur que le produit ne peut être utilisé en toute sécurité dans les climats non tropicaux. AHB2 Instruction Manual Rev F Page 35...
à émettre des ondes excessive et les interférences magnétiques. Des modifications peuvent réduire l'immunité aux perturbations extérieures. Ne faites appel un personnel qui offrent des services de modification de produit. AHB2 Instruction Manual Rev F Page 36...
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Toujours remplacer les deux fusibles en même temps. 18. Ce produit ne peut être utilisé en toute sécurité à des altitudes inférieures à 2000 mètres. 19. Ce produit ne peut être utilisé en toute sécurité dans les climats non tropicaux. AHB2 Instruction Manual Rev F Page 37...
Appendix A Radical Approach to Power Amplification The performance of the AHB2 would not have been achievable without taking a radical approach to power amplification. In many ways, the AHB2 is a complete 180 degree departure from traditional high-end amplifier designs.
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Low Gain – The AHB2 has a low gain setting that optimizes the gain structure of professional monitoring systems. Maximum rated output is reached at an input signal level of 22 dBu. This places the upstream equipment in an ideal operating range to maximize the SNR of the monitoring chain.
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NL4 jacks. But, for the highest performance, we recommend using the NL4 jacks. The jacks accept NL4 or NL2 plugs. In summary, Benchmark has taken a radical approach to audio amplification, has leveraged patented technologies (licensed from THX Ltd.), and has reversed many common practices. The result is an amplifier that is significantly quieter, cleaner, smaller, and more efficient than any traditional design.
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