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****** Page 1 ****** Owner’s Manual Model VT130 STEREO POWER AMPLIFIER audio research HIGH DEFINITI O 5740 GREEN CIRCLE DRIVE / MINNETONKA, MINNESOTA 55343-4424 / PHONE 612/939-0600 FAX 612/939-0604

****** Page 2 ****** Contents Model VT130 Section Introduction. Construction and Testing Packaging/Unpacking Accessories Warnings . Preparation for Use Use of Controls Installation Panel Connections and Controls Connection and Control Instructions Operating and Adjustment Procedure Servicing Cleaning Warranty Terms and Conditions Warranty Outside the USA Specifications øøøøøøø Page No. i

****** Page 3 ****** Model VT130 Introduction Please take time to carefully read and understand the following information and instructions before you install or attempt to operate your Audio Re- search VT 130 power amplifier. Becoming familiar with important facts about your amplifier and its correct operating procedures will help assure you of maximum musical satisfaction and reliable opera- tion. The effort you invest now will be well reward- ed as time goes by. Model VT130 The VT 130 vacuum-tube stereo audio power amplifi- er provides an expression of the state-of-the-art in vacuum-tube technology as it exists today at Audio Research Corporation. The design objectives for this product were two-fold: 1) to provide an amplifier that would allow the improvements in musical accu- racy of such products as the LS2, LS5, PH2, etc., to be fully realized, and 2) to provide an all-vacuum tube amplifier that would approach the reliability of good solid state amplifiers. The VT 130 is housed in a massive heli-arc welded chassis and fully ventilated top cover. Using 4 matched pair of 6550 output tubes, two 12 BH7 dri- ver tubes and four 6922 dual triodes for input-stage gain, the VT 130 is rated at 110 watts per channel R. M. S. The amp is fully balanced input-to-output, and uses a combination of ultralinear operation with Audio Research patented partial cathode coupling in the output stage. This output configuration exhibits minimal sensitivity to variance in loudspeaker im- pedance. The power supply bulk energy storage is rated at 280 joules and power supply regulation is all solid-state, while all gain is supplied by vacuum tubes. Parts quality is the best currently available, and the overall circuit layout is maximized for sonic purity: XLR inputs at one end, with power switch, line fuse and proprietary heavy gold plated binding parts (for 4, 8 and 16 ohm impedances) at the other end. It should be expected that this amplifier will pro- duce musically satisfying results for as long as you care to own it. Construction and Testing Like every Audio Research product, your VT 130 power amplifier has been designed and carefully handcrafted in the U.S.A., using precision mechani- cal parts, electronic components and assembly pro- cedures similar to those used in the manufacture of scientific equipment and musical instruments. To as- sure consistent performance standards, each VT 130 is visually inspected at several assembly points, test run, electronically tested and sonically evaluated pri- or to shipment. This time-consuming perfectionist approach to the design and manufacture of audio equipment is in- tended to provide you with the best in musical satis- faction and lasting value. Packaging Save all the packaging in a dry place. Your Audio Re- search amplifier is a precision electronic instrument and should be properly cartoned any time shipment is made. Because of its weight, it is highly probable that the unit will be damaged during shipment if repackaged in cartoning other than that designed for the unit. You may not have occasion to return the unit to the factory for service, but if that should prove necessary or other occasion to ship it occurs, the original pack- aging may save your investment from unnecessary damage, delay and expense. Unpacking The VT 130 is packed within two cartons (inner and outer) which have impact-absorbing panels in be- tween. Because of the weight of the unit and be- cause it is a precision electronic instrument it is nec- essary to take reasonable care of its unpacking and preparation for use. It is best to have a large, open work area with two people available to help. Set the carton upright in the center of the work area and with a small knife care- fully slit the taped edges of the outer carton’s top flaps. Fold the flaps to the sides and while holding 1

****** Page 4 ****** Model VT130 the inner carton in place, roll the unit upside down. You can now lift the outer carton off and set it and the filler panels aside. Now slit the inner carton’s taped seams on the bottom (now facing upward). Again, fold the flaps over and while holding the unit in, roll it over as before. You can now lift the inner carton off to find your VT 130 sitting upright, un- damaged and uncartoned. Carefully remove the plas- tic wrap. Now, while you remember how, reassem- ble the carton system for future use. Accessories 1 — Phillips-head screwdriver for cover removal 1 — Plastic screwdriver for bias adjustments User replaceable spare fuses include: 1/4 Amp AGC 250V normal-blow (Internal) 1- 1-6 1/4 Amp MDX 125V slo-blow with 120V units 1 7 Amp MDX 125V slo-blow with 100V units 1 – 3 Amp MDQ 250V slo-blow with 220V/240V units Warnings 1. To prevent fire or shock hazard, do not expose your VT 130 to rain or moisture. 2. This unit contains voltages which can cause seri- ous injury or death. Do not operate with covers removed. Refer servicing to your authorized Audio Research dealer or other qualified personnel. 3. The 16-gauge, 3-conductor power cord on your VT130 is equipped with a standard 3-prong grounding plug. If used normally, it will provide a safe earth ground connection of the chassis. Refer to the section on “AC Power Connections” for de- tailed information. 2 4. For continued protection against fire hazard, re- place fuses only with the same type and rating of fuses as specified. Preparation for Use Your VT 130 amplifier is shipped with the vacuum tubes packed in individual protective cartons. These must be unpacked and installed before you attempt to operate the amplifier. Proceed according to the fol- lowing instructions. 1. Using the Phillips-head screwdriver provided, re- move the top cover assembly, setting it and the re- taining screws aside. 2. Carefully remove each vacuum tube from its car- ton and match its location number (written on the base of the tube and on its protective carton) to the number printed next to each socket on the cir- cuit board. Firmly seat each tube in its matching socket, taking care to “key” the tube pins to the socket holds. Retain the tube cartons with other packing materials for possible future use. 3. Once all vacuum tubes have been installed, reposi- tion the top cover assembly over the chassis and, re-install the screws. Note: Contact Enhancers are not recommended for use on vacuum tube contact pins. With continual ex- posure to heat and air, these substances can form gummy, dust-collecting residues which actually re- duce contact and degrade sonic performance. Proper external use of these preparations on interconnect plugs, speaker connections, etc. — is subject to the discretion of the owner.

****** Page 5 ****** Model VT130 Use of Controls POWER-ON SWITCH: Initiates/terminates AC line power to the amplifier. Function indicated by green LED above toggle switch. Note: Audio Research does not recommend leaving your VT 130 “on” 24 hours a day as is the custom of some audiophiles to achieve maximum sonic perfor- mance on demand. While this is often recommend- ed for solid-state equipment, Audio Research does not recommend this procedure for vacuum tube power amplifiers. (2,000 hours of tube life will pass by in 84 days!) Installation To insure normal component life and safe operation this unit must be operated only In a horizontal (upright) position. Adequate air flow and proper cooling thereby can occur only if there is no restric- tion below, behind and above the unit. The eight (8) special non-marring elastomer feet pro- vide adequate spacing only from a smooth, hard sur- face. If the unit is to be operated in an enclosure such as an equipment rack, make certain that adequate air flow above and below the unit is provided. The “ambient” operating temperature should never ex- ceed 1200 F or 490 C. Improper installation will cause premature tube failure and will affect your warranty, as well as the service life of the unit. It is normal for a vacuum tube power amplifier to run quite “warm”, and if used for prolonged periods, “hot” to the touch. All components within are, how- ever, operated at safe, conservative levels and will not be improperly affected thereby, providing the re- quirements outlined above are adhered to. RIGHT CHANNEL OUTPUT OFF CAUTION 50/60 OHM TAP iO B TOTVM0 WITH COMMON GÄOUNO. Panel Connections and Controls 2 — XLR inputs (right and left) The other end panel has: 1 — Power Cord I Fuse Post 1 Power On-Off Switch 1 LED On Indicator 8 — Output binding posts for various output impedances Connection and Control Instructions The amplifier should always be turned on and off via its own power on-off switch. Because of the very high energy storage within this amplifier, special warm-up circuitry is provided which gets its se- quencing from it’s own Power On-Off Switch. Fur- ther, other discrete components of an audio system should be turned on first. Otherwise, with some equipment, the amplifier will reproduce warm-up thumps, etc., some of which could be harmful to your speaker system. Audio Research preamplifiers have automatic warm-up muting, and are much less likely to exhibit this problem; however, good operat- ing practice says “Turn the amplifier on last, and turn It off first. f’ The VT 130 input is “balanced” and therefore re- quires a preamplifier with a balanced output, or, the addition of an Audio Research BLI between a single- ended output preamplifier and the input of the VT130. Proprietary and non-twisting output connectors are employed for each impedance. Simply observe the legend, connecting your speakers to the appropriate set of binding posts for their rated impedance. O BOO W MAX LEFT CHANNEL OUTPUT CAUTION a OHM TAP 10 OROUNO*O. AVOID ANO TEOTINO OTØTZMO WITH COMMON 3

****** Page 6 ****** Model VT130 IMPORTANT: Use the best available speaker wires and interconnects. Audio Research cannot empha- size this enough. As better components and systems are developed, it becomes increasingly important to avoid the limitations of inferior system interconnec- tions. For best results we recommend Audio Research LitzLink@ interconnects and LitzLine@ speaker cables. Audio Research uses circuitry called “partial cathode coupling” in all of its vacuum tube and hybrid power amplifier designs. This requires the 4 ohm taps to be grounded, which is of no consequence when using most loudspeakers. Simplly connect the “negative” speaker lead to “0” and the ‘Vositive” speaker lead to 4, 8 or 16 ohms, as required. Some loudspeakers, or some speaker switch boxes, have “common ground” systems, either by hookup between the speakers or in a special crossover de- vice. Most headphone adaptor boxes also have a common ground. In these instances it is important to connect the “negative” speaker leads (or head- phone common leads) to the “4” ohm taps rather than the 80″ ohm taps to avoid shorting the amplifier or causing monaural performance to occur. Use ei- ther “0” ohms or “16” ohms for the “positive” speaker leads. (The /’0″ ohm tap will provide an inverted sig- nal. Contact your authorized Audio Research dealer or Audio Research Customer Service Department for help with these special cases. It is important sonically that your entire system be connected so that the audio signal arriving at the speakers has correct, or “absolute” polarity (i.e., non- inverted). Connect the black or speaker terminial to the wire that connects to the “0” terminal on the VT 130. Connect the red or “+1’ speaker terminal to the wire that connects to the “8” or 16″ terminal on the VT 130. Use the best available speaker cables and tighten the terminals securely to ensure best sonic results. MATCHING: It is important to use as close as possi- ble an impedance match between the amplifier and speaker for optimum transfer of power to the speak- er with minimum distortion. In the case of speaker systems with significant variations in impedance throughout the frequency spectrum, such as most electrostatic types, determine the best impedance match empirically for best overall sonic results. Connect the VT130 input to the preamplifier or elec- tronic crossover, using only the highest grade of 4 audio interconnect cables. To avoid sonic degrada- tion use the shortest practical length of cables. AC POWER CONNECTIONS: It is essential that the VT130 amplifier be connected to a wall AC power re- ceptacle, or a similar heavy-duty source. If it is con- nected to convenience receptacles on preamplifiers, etc., the full sonic capabilities of both the VT 130 and the preamplifier may be compromised. Furthermore, the proper control of start-up and shut-down surges may not occur unless the power switch on the front of the VT 130 is actually used for on/off control of the amplifier. The AC power source for the VT 130 amplifier should be capable of supplying 15 amperes for 100 or 120 volt units, or 8 amperes for 220 or 240 volt units. For the very best performance on domestic 100 or 120 volt circuits, the VT 130 should be connected to its own AC power circuit branch, protected by a 15 amp breaker. The preamplifier and other audio equipment should be connected to a different power circuit and breaker. If the power receptacle of the VT 130 is more than 25 feet from the building power entrance and breaker box, it would be preferable to use installed wiring capable of 30 amperes to mini- mize voltage drop, using a 15 amp breaker. Avoid the use of extension cords. If they must be used on a temporary basis, use 14-gauge or heavier cords. The VT130 utilizes a compatible grounding system that generally does not require a “ground lifter” adapter plug on the AC power cord to minimize hum. The power cord on your VT 130 has a standard three-prong grounding plug to provide maximum safety when it is connected to a ground wall recepta- cle. If there is any question regarding the safety of grounding procedures, be certain to seek competent help with the installation. If electronic crossovers or other AC powered equip- ment is used with the VT 130 it may be necessary to use “ground lifter” adapters on the power plugs of that equipment to minimize system hum. Generally, the lowest hum is achieved when the only direct connection between audio common “ground” and true earth ground occurs in the preamplifier, through its grounded power cord. Other equipment in the system should have some form of isolation to pre- vent ground loops and associated hum. Always place the power on-off switch on the panel of the VT 130 in the “Off” position before connecting the power line cord to AC power.

****** Page 7 ****** Model VT130 Operating and Adjustment Procedure 1. Make sure you have read and complied with the INSTALLATION AND CONNECTION instructions prior to attempting operation. 2. Make sure your VT 130 is properly connected to a high-current power receptacle via the attached power cord (see CONNECTIONS). 3. Your preamplifier should be “On” and muted and/or set at minimum gain. 4. Your VT 130 will now operate satisfactorily. How- ever, a full stabilization or warm-up period of at least one-half (1/2) hour is recommended for best sonic performance. Servicing Because of its careful design and exacting standards of manufacture, your VT 130 amplifier should nor- mally require only minimal service to maintain its high level of performance. CAUTION: The VT 130 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. Refer any needed service to your authorized Audio Re- search dealer or other qualified technician. The vacuum tubes inside the VT130 are high-quality 6550, 12BH7, and 6922 types. Replacement output tubes should be matched for best sonic performance, although that is not a requirement for good sound. Reliable, matched, low gas 6550 tubes such as those available from Audio Research are strongly recommended for maximum performance and longevity. Observe the operating and adjustment procedure for adjusting bias when replacing any power output tubes. Additional questions regarding the operation, main- tenance or servicing of your amplifier may be re- ferred to the Customer Service Department of Audio Research Corporation; 612-939-0600. When ordering a service manual from Audio Research or an autho- rized dealer, be sure to identify the serial number on your amplifier. Cleaning To maintain the visual appearance of your amplifier, occasionally wipe the front panel and top cover sur- faces with a soft, damp (not wet) cloth to remove dust. A mild, non-alkaline soap solution may be used to remove fingerprints or similar smudges. Cleaners containing abrasives should not be used as they will damage the “brushed” grain of the front panel finish. 5

****** Page 8 ****** 3-Year Limited Warranty Terms and Conditions 1. LIMITED WARRANTY Audio Research warrants the product designated herein to be free ofmanufacturing defects in material and workmanship, sub- ject to the conditions hereinafter set forth, for a period of three (3) years from the date of purchase by the original purchaser or no later than five (5) years from the date of shipment to the authorized Audio Research dealer, whichever comes first, except- ing vacuum tubes which are warranted for 90 days only (See 6). 2. CONDITIONS This Warranty is subject to the following conditions and limita- tions. The Warranty is void and inapplicable if the product has been used or handled other than in accordance with the instruc- tions in the owner’s manual, abused, or misused, damaged by accident or neglect or in being transported, or the defect is due to the product being repaired or tampered with by anyone other than Audio Research or an authorized Audio Research repair center. The product must be packed and returned to Audio Research or an authorized Audio Research repair center by the customer at his or her sole expense. Audio Research will pay return freight of its choice. A RETURNED PRODUCT MUST BE ACCOMPANIED BY A WRITTEN DESCRIPTION OF THE DEFECT AND A PHOTOCOPY OF THE ORIGINAL PURCHASE RECEIVE This receipt must clearly list model and serial number, the date ofpurchase, the name and address ofthe purchaser and authorized dealer and the price paid by the purchaser. Audio Research reserves the right to modi the design ofany product without obligation to purchasers o previously manufactured products and to change the prices or specifications ofany prod- uct without notice or obligation to any person. 3. REMEDY In the event the above product fails to meet the above Warranty and the above conditions have been met, the purchaser’s sole remedy under this Limited Warranty shall be to return the pro- duct to Audio Research or an authorized Audio Research repair center where the defect will be rectified without charge for parts or labor, except vacuum tubes (See 6). 4. LIMITED To ORIGINAL PURCHASER This Warranty is for the sole benefit of the original purchaser of the covered product and shall not be transferred to a subsequent purchaser of the product. 5. DURATION OF WARRANTY This Warranty expires on the third anniversary ofthe date ofpur- chase or no later than the fifth anniversary of the date of ship- ment to the authorized Audio Research dealer, whichever comes first. Warranty Outside the U.S.A. Audio Research has authorized distribution in many countries ofthe world. In each country, the authorized importing retailer or distributor has accepted the responsibility for warranty ofour products. Warranty service should normally be obtained from the importing retailer or distributor from whom you purchased your product. 6 6. VACUUM TUBES Vacuum tubes are warranted for the original 90-day period only. 7. DEMONSTRATION EQUIPMENT Equipment used by an authorized dealer for demonstration pur- poses is warranted to be free of manufacturing defects in materials and workmanship for a period ofthree (3) years from the date ofshipment to the dealer. Vacuum tubes are warranted for 90 days. After the first year, demo equipment needing war- ranty service must be packed and returned to Audio Research by the dealer at his sole expense. Audio Research will pay return freight of its choice. A returned product must be accompanied by a written description ofthe defect on an AUDIO RESEARCH RETURNED GOODS AUTHORIZATION form. Dealer-owned demonstration equipment sold at retail within three (3) years of date of shipment to the dealer is warranted to the first retail customer to be free of manufacturing defects in materials and workmanship for the duration ofthe 3 -Year Limited Warranty re- maining (as measured from the date of shipment of the equip- ment to the dealer). Vacuum tubes are not warranted for any period under these conditions ofsale. In the event warranty ser- vice is needed under these conditions, the owner of the equip- ment must provide a copy ofhis purchase receipt, fulfilling the requirements described under ‘i 2. Conditions” above. The pro- duct must be packed and returned to Audio Research or an authorized Audio Research repair center by the customer at his or her sole expense. Audio Research will pay return freight ofits choice. 8. MISCELLANEOUS ANY IMPLIED WARRANTIES RELATING TO THE ABOVE PRODUCT SHALL BE LIMITED TO THE DURATION OF THIS WARRANTY THE WARRANTY DOES NOT EXTEND ero ANY INCIDENTAL OR CONSEQUENTIAL cosrrs OR DAMAGES To THE PURCHASER. Some states do not allow limitations on how long an implied warranty lasts or an exclusion or limitation of incidental or consequential damages, so the above limitations or exclusions may not apply to you. This Warranty gives you specific legal rights, and you may also have other rights which vary from state to state. 9. WARRANTOR Inquiries regarding the above Limited Warranty may be sent to the following address: Audio Research 5740 Green Circle Drive, Minnetonka, Minnesota 55343-4424. ATTN: Customer Services In the unlikely event of service required beyond the capability ofthe importer, Audio Research will fulfill the conditions of the warranty. Such product must be returned at the owner’s expense to the Audio Research factory, together with a photocopy of the bill ofsale for that product, a detailed description ofthe problem, and any information necessary for return shipment.

****** Page 9 ****** Specifications Model VT130 POWER OUTPUT: 110 watts per channel continuous at 16 ohms from 2()Hz to 20kHz with less than 1.00/0 total harmonic distortion (typically below .05% at 1 watt). Approximate actual power available at “clipping” 120 watts (1 kHz). (Note that actual power output is depen- dent upon both line voltage and “condition” i.e.: if pow- er line has high distortion, maximum power will be affected adversely, although from a listening stand- point this is not very critical.) POWER BANDWIDTH: (-3dB Points) 15Hz to 80kHz. FREQUENCY RESPONSE: (-3dB Points at watt) 5Hz to 160 kHz. INPUT SENSITIVITY: 1.2V RMS balanced for rated output. INPUT IMPEDANCE: 200K ohms balanced. OUTPUT REGULATION: Approximately 0.5dB 16 ohm load to open circuit (Damping factor approxi- mately 16). OVERALL NEGATIVE FEEDBACK: 20dB. SLEW RATE: 17 volts/microsecond. RISE TIME: 2.0 microseconds. HUM & NOISE: Less than 0.5mV RMS 98dB below rated output (IHF weighted, input shorted). POWER SUPPLY ENERGY STORAGE: Approxi- mately, 28() joules. POWER REQUIREMENTS: 105-125VAC 601-lz (210- 250VAC 50Hz) 620 watts at rated output, 900 watts maximum, 380 watts at “idle”. TUBES REQUIRED: 4 -e Matched pair 6550 Power Output; 2-12BH7A Driver; 4-6922 input. DIMENSIONS: 141/2″ (37 cm) W x 12″ (30.5cm) H x 22″ (56 cm) D. Output connectors extend 1″ (2.5 cm) to the rear. WEIGHT: 69 lbs. (31.4 kg) Net; 95 lbs. (43.2 kg) Shipping. Specifications subject to change without notice. 01993 Audio Research Corporation. 7








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