Benchmark AHB2 Instruction Manual

Benchmark AHB2 Instruction Manual

Reference stereo power amplifier 100w/channel into 8-ohms 380w bridged mono into 8-ohms
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Benchmark AHB2
Instruction Manual
Reference Stereo Power Amplifier
100W/channel into 8-Ohms
380W bridged mono into 8-Ohms

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Table of Contents
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Summary of Contents for Benchmark AHB2

  • Page 1 Benchmark AHB2 Instruction Manual Reference Stereo Power Amplifier 100W/channel into 8-Ohms 380W bridged mono into 8-Ohms...
  • Page 2: Table Of Contents

    Bidirectional 12 Volt Trigger Safety Linking Multiple Audio Components Warranty Information Trigger Wiring Benchmark 1-Year Warranty Trigger Cables Benchmark Extended Warranty Options 34 Automatic Power-Down Feature Notes on Warranty Repairs 45 Minute Timer Consignes de Sécurité Importantes Activates the 12V TRIGGER (French) No Warm-Up Required Symboles de Sécurité...
  • Page 3: Introduction

    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.
  • Page 4: Important Safety Instructions

    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...
  • Page 5: Safety Precautions

    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.
  • Page 6 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...
  • Page 7: Front Panel

     Power Indicator  Channel 1 Clip Indicator  Channel 1 Temperature Indicator  Channel 1 Mute Indicator  Channel 2 Mute Indicator  Channel 2 Temperature Indicator  Channel 2 Clip Indicator AHB2 Instruction Manual Rev F Page 7...
  • Page 8: Rear Panel

    NL4 Speaker Output for Channel 1, or Channels 1 and 2  Balanced XLR Input for Channel 1, or for Bridged Mono  2-Position Mode Switch - Enables Bridged Mono Mode  12 Volt Trigger Input / Output Connector AHB2 Instruction Manual Rev F Page 8...
  • Page 9: Quick Start Guide

    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.
  • Page 10: Connect The Audio Inputs

    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.
  • Page 11: Connect The Ac Power Cord

    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...
  • Page 12: Bidirectional 12 Volt Trigger

    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.
  • Page 13: Rack Mounting

    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.
  • Page 14: Fault Protection Circuitry

    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.
  • Page 15: Protect Mode - Fault Codes

    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...
  • Page 16: Clipping Fault

    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...
  • Page 17: Over-Current Fault

    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...
  • Page 18: Soa Fault

    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...
  • Page 19: Over-Temperature Fault

    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...
  • Page 20: Power Supply Fault

    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...
  • Page 21: Specifications

    < -118 dB (< 0.00013%) - Mono Mode 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 AHB2 Instruction Manual Rev F Page 21...
  • Page 22: Crosstalk

     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...
  • Page 23: Mechanical Drawings

    Mechanical Drawings Dimensions AHB2 Instruction Manual Rev F Page 23...
  • Page 24: Rack-Mount Dimensions

    Rack-Mount Dimensions AHB2 Instruction Manual Rev F Page 24...
  • Page 25: Performance Plots

    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.
  • Page 26 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.
  • Page 27 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.
  • Page 28 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...
  • Page 29 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.
  • Page 30: Regulatory Compliance

    (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)).
  • Page 31: Ce Certificate Of Conformity

    CE Certificate of Conformity AHB2 Instruction Manual Rev F Page 31...
  • Page 32: Safety

    Rated Input Voltage: 100-120 Vac; 220-240 Vac  Rated Frequency: 50/60 Hz  Rated Input Current: 8A  Protection Class: I Tested according to:  CAN/CSA C22.2 60065/A1:2006  UL 60065:2007  EN60065/A12:2011 Certification Mark: AHB2 Instruction Manual Rev F Page 32...
  • Page 33: Warranty Information

    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.
  • Page 34: Benchmark Extended Warranty Options

    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.
  • Page 35: Consignes De Sécurité Importantes (French)

    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...
  • Page 36: Mesures De Sécurité

    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...
  • Page 37 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...
  • Page 38: Appendix

    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.
  • Page 39  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.
  • Page 40 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.
  • Page 41 Copyright © 2014 Benchmark Media Systems, Inc. All rights reserved. Benchmark Media Systems, Inc. 203 East Hampton Place, STE 2 Syracuse, NY 13206-1633 PHONE: +1-315-437-6300 FAX: +1-315-437-8119 www.benchmarkmedia.com AHB2 Instruction Manual Rev F Page 41...

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