Owner’s Manual Reference 750 Monaural Amplifier
Contents Reference 750 Monaural Amplifier Illustrations 3 – 4 Preface 5 Packaging 5 Accessories 5 Vacuum Tubes and Preparation for Use 5 Installation 5 – 6 Warnings 6 Description of Controls 6 – 7 Connections 7 – 8 Operating Procedure 8 Installation of Optional Cover 8 Servicing 9 Cleaning 9 Disposal and Recycling Guidelines 9 Limited Warranty 9 Specifications 10 2
POWER OUTPUT/BIAS V15 V1 V13 V11 CHECK V3 V5 V9 V10 V7 V8 CHECK V12 V14 CHECK V6 V4 V16 V2 CHECK SET SET FAN LIGHT BIAS METER LINE VOLTAGE POWER VACUUM TUBE POWER AMPLIFIER REFERENCE 750 HIGH DEFINITION 3 R
INPUT 200K BAL HOUR METER RESET REFERENCE 750 MONAURAL AMPLIFIER PLYMOUTH, MINNESOTA MADE IN U.S.A. CAUTION RISK OF ELECTRIC SHOCK DO NOT OPEN ! WARNING TO PREVENT FIRE AND SHOCK HAZARD, DO NOT EXPOSE THIS DEVICE TO RAIN OR MOISTURE. UNIT MUST BE OPERATED IN A HORIZONTAL POSITION. -DO NOT OPERATE WITH COVERS REMOVEDUNIT CONTAINS VOLTAGES WHICH MAY BE HAZARDOUS. WARNING CAUTION RISK OF HAZARDOUS ENERGY! MAKE PROPER SPEAKER CONNECTIONS SEE OWNERS MANUAL.
Preface Please take time to carefully read and understand the following information and instructions before you install or attempt to operate your Audio Research Reference 750 vacuum tube monoblock power amplifier. Becoming familiar with important facts about your amplifier and its correct operating procedures will help assure maximum musical satisfaction and reliable operation. Packaging Save all packaging accompanying this product.
of your support system to be sure it is rated to handle this weight. If the unit is to be operated in an enclosure such as an equipment rack, make certain that adequate air flow above and to each side of the unit is provided. The “ambient” operating temperature should never exceed 120º F or 49º C. Additional ventilation can be provided by fan-cooled, perforated tube covers available for purchase through your Audio Research dealer.
hole in the front panel in same way the V1 tube bias level is adjusted. Again, press the BIAS switch repeatedly to check V4, V6, V8, V10, V12, V14 and V16 tube bias levels, which should all be within the bias range arc. Note that each of the even V number tube bias levels are controlled by the V2 bias setting. Note that the corresponding V number LED is illuminated for each output tube as you proceed through the bias adjustment and monitoring sequence.
amplifier will amplify any extraneous turn-on noises those components might generate, which could potentially damage the loudspeakers. Good operating practice dictates that the amplifier should be turned on last, and turned off first in an audio system. The Reference 750 uses a grounding system that does not require a ground-lifter adaptor plug on the A. C. power cord to minimize hum.
Servicing Limited Warranty Because of its careful design and exacting standards of manufacture, your Reference 750 amplifier should normally require only minimal service to maintain its high level of performance. CAUTION: The Reference 750 amplifier contains sufficient levels of voltage and current to be lethal. Do not tamper with a component or part inside the unit. Even with the power turned off, a charge remains in the energy storage capacitors for some time.
Specifications POWER OUTPUT: 750 watts per channel continuous from 20Hz to 20kHz. 1kHz total harmonic distortion typically 0.5% at 750 watts, below .04% at 1 watt. Approximate actual power available at “clipping” 850 watts (1kHz). (Note that actual power output is dependent upon both line voltage and “condition” i.e.: if power line has high distortion, maximum power will be affected adversely, although from a listening standpoint this is not very critical.) POWER BANDWIDTH: (-3dB points) 15Hz to 150kHz.
