Audio Research was founded by William Z. Johnson. His efforts almost single-handedly revived vacuum-tube designs at a time when major manufacturers had abandoned this technology for low-cost solid-state devices which were inferior in terms of musical accuracy.

Audio Research prides itself on manufacturing only products which will provide genuine enjoyment for as long as the customer cares to own them. Their products have demonstrated lasting value after purchase. More than a few models have acquired legendary "collector" status and continue to resell for as much or close to what they originally cost. Audio Research has come to represent stellar performance and lasting value for music lovers and audio enthusiasts everywhere.

Have a read through >>all of Audio Research Reviews<<

PREAMPS

Reference 3 Line-Stage Preamplifier, Audio Research

With the REF3 redefining what is possible in ultimate preamplifier performance and the LS26 creating a new performance benchmark in a slightly smaller package, we are very proud to introduce the LS17, a new preamplifier offering much of their performance and musicality in a more affordable package.

The new LS17 retains the strong feature set of the previous LS16 series, offering two balanced and five single-ended inputs, and two balanced and one single-ended output. A monitor input and record output are also provided.

On the front panel, the changes are more obvious. A new linear LED display provides a 20-lamp display for the 104-step volume control, as well as indicators for selected input and muting. One rotary control is provided for volume adjustment, while a second controls input select. Pushbuttons are provided for power, monitor, processor (unity gain) and mute. All functions are also accessible via the included handheld remote. For systems using a master controller, all LS17 functions are individually addressable by discrete codes. Handles are included as part of the standard LS17 package.

But it is in the LS17's remarkable new level of performance that you will experience the biggest difference from its predecessor. Using two 6H30 twin triodes in the audio stage, the LS17 has a larger power transformer, redesigned power supply and new parts including proprietary output coupling caps. This gives the LS17 the stunning purity of sound first heard in the REF3 and in the more recent LS26. The family resemblance is undeniable, and convincing. The LS17 has an easy flow to its presentation, but it resolves musical and spatial information at a much higher level than the LS16 series was ever capable of. Instrument focus, soundstage clarity and bass definition are all vividly enhanced. Members of our listening panel agree that if the LS26 is the "REF3 Jr.," then the LS17 is surely the "Baby REF3." The pedigree is only too clear, and you will hear it immediately and without effort.

With the introduction of the LS17, Audio Research now offers benchmarks in preamplifier quality, performance and value at three distinct price points. Our lineup has never been stronger. Hear for yourself how an LS17 can transform your system and make music much more enjoyable.


LS17 Specifications:

The SP16/SP16L Tube Preamplifier 

The SP16 is completely single-ended with five sets of inputs (labeled Phono, CD, Tuner, Video and Aux) plus a Processor pass-through. There are two sets of main outputs for flexibility, plus a Tape out. The SP16 has a 12-volt trigger to turn on power amplifiers or other equipment, and full remote control of all functions including power, input selection, stereo/mono, volume, and muting. 

Specs

Look inside, and you will see the same beautiful construction quality found in its more costly siblings: the same expensive board material, the same extra-thick copper circuit traces, even the same point-to-point wiring and hand-soldering of parts. Machined RCA connectors, not cheap imitators. The SP16 is pure Audio Research, pure Class-A, with all-tube gain in both line and phono stages utilizing three select 12AX7 tubes in each circuit (six total). 

Circuit highlights include regulated power supplies with a total of eight high and low-voltage regulators, high-energy storage plate supply, Audio Research's patented DEC filter cap decoupling, high performance input-selection relays allowing short audio paths, and 70-step digitally-controlled analog-switch volume control with precision tracking. Dual low-impedance cathode-follower main outputs allow you to easily drive two power amplifiers simultaneously. Gain for the line inputs is 12dB. Total gain from the phono input to the main outputs is 54dB, suitable for moving-magnet and high-output moving coil cartridges.

Sonically, the SP16 is pure fun as it easily unravels fine musical lines, bouncing along with surprising micro and macro-dynamic swings. The soundstage is big, airy and dimensional.  The SP16 is so good that it can be partnered with a vintage D100 or a new VT200MKII and sound glorious either way. 

The SP16 without the phono stage is designated the SP16L. The front panels of both versions are identical, except that on the "L" version the Phono LED will not light when selected. On the rear panel there are no RCA input jacks where the phono inputs would be, there is no ground post, and the model is listed as SP16L. Internally the phono stage is on the main board along with the line amp section, but will not be "stuffed" with components, tube sockets, etc. on the line-only version. Yes, the phono section can be added at a later date at the Audio Research factory. 

Power Amps

Reference 110 Specifications:

Reference 110 Stereo Power Amplifier

Following the successful introduction of the Reference 610T, it is time for a more affordable, compact amplifier to fill the void left by the discontinuation of the VTM200 and REF300MKII. We are pleased to announce the introduction of the new Reference 210 monoblock, a product which will allow a greater number of music lovers access to the Reference series of amplifiers.

The Reference 210 presents a familiar yet distinctive appearance. The chassis is enclosed, with a thick front panel the same height and width as the VT100/VTM200, but with a vacuum-flourescent display screen like the one featured on the REF3 and REF610T. The chassis is 19.5" deep (plus handles) and has an internal frame like the 150M, with a one-piece ventilated cover that wraps around the top and sides. The front panel is available in Natural or Black finishes.

The vacuum-flourescent display has the same functions as the display on the REF610T, but they are addressable only through the handheld remote control. Functions include the choice of six levels of illumination, plus off; bias measurements for each output tube; A.C. line voltage; logarithmic, scalable power output (0-10, 0-50, 0-100, 0-200 watts); and total hours of tube use.

The internal layout is all new, with the main circuit boards mounted horizontally instead of vertically. The transformers are mounted on a raised central channel running front to back; on one side of the channel is a large circuit board containing all of the audio stages, and on the other side is a large circuit board with the power supply, contributing to a very clean and attractive appearance. There is a small Papst fan mounted on the rear panel to circulate air over the audio stages. The 12V D.C. fan runs continuously at a fixed low speed whenever the amplifier is powered-up.

Power output is 210 watts continuous. Like the REF610T, the REF210 is based upon a push-pull, fully balanced vacuum-tube circuit running in partial cathode coupling mode, utilizing three matched pairs of 6550C output tubes. The REF210 uses two 6550C driver tubes, each controlling three output tubes operating in unison. The input stage uses direct-coupled JFETs, followed by a 6N1P vacuum-tube amplifying stage. As with the REF610T, the biasing system is very simple, with only two bias adjustments.

Power supply energy storage is a monstrous 787 joules, three-quarters the size of the REF610T. (Compare that with the REF300MKII's 448 joules.) Shared with the REF610T are new proprietary coupling caps and extensive film-cap bypassing of all electrolytics in the power supply. There is tube regulation of the input stage, with six additional solid-state regulators. Power supply rectification is solid-state with a total of seven regulators. The massive, custom output transformer is an ultra-widebandwidth design: the frequency response of the REF210 is an incredible 0.5Hz to 240kHz (-3dB). Also, as in the REF610T, 50% coupling of the output stage cathodes to the transformer yields both higher efficiency and better sound than conventional pentode or triode operation.

Input is balanced only, while the output has separate taps for 4-8-16 ohm speaker loads. As expected, there is a 20A IEC connector for power, but unlike the REF610T, the REF210 has a 12V trigger to allow remote turn-on.

Sonically the Reference 210 is simply stunning in every respect. Resolution of detail is uncanny, with a vivid, transparent, you-are-there quality that is captivating. The performers are not mere images, but have real body, weight and presence. The soundstage is unbounded, with palpable space and air. Fine dynamic shadings and crescendos alike are unrestrained. And, bass impact, speed and articulation are a revelation. Once you have heard them, you will not soon forget the magic of these amplifiers.

Be sure to schedule an appointment with your Audio Research dealer to audition the Reference 210 amplifiers soon - you will never regret it.

Reference 210 Monaural Amplifier, Audio Research

 

 

 

REFERENCE 610T Amplifier

When the Reference 600 Power Amplifier was introduced in 1995 it set a new standard for High Definition® in music reproduction. In every meaningful category, the Reference 600 - 300 amplifier series remained at the pinnacle of audiophile performance. Now the REF600-300 legacy continues with a new flagship from Audio Research: the Reference 610T monoblock.

Like its predecessors, the 610T monoblock is based upon a push-pull, fully balanced vacuum-tube circuit using 6550C output tubes (16 in all). But unlike the earlier models, the 610T uses two 6550C driver tubes, each controlling a bank of eight output tubes operating in unison. Input gain is provided by two 6N1P dual triodes and a 6H30 follower. This means fewer tubes to replace, and a much simpler biasing system: two bias adjustments instead of the 16 required in the REF600 series. Power output is rated at 600+ watts into 4, 8 or 16-ohm loads. Projected tube life is approximately 2000 hours.

Power supply energy storage has been increased to a whopping 1000 joules, with extensive film-cap bypassing of all electrolytics. In addition, interstage coupling caps are the new proprietary types first used in the REF3 preamplifier. Power-supply rectification is solid-state, while a total of six regulators are used: there is tube regulation of the input stage, with five additional solid-state regulators. The massive, custom output transformer is an ultra-wide-bandwidth design allowing a high damping factor and excellent current delivery. And, 50% coupling of the output-stage cathodes to the transformer yields both higher efficiency and better sound than conventional pentode or triode operation. Input is balanced only, with separate output taps for 4 - 8 -16 ohm speaker loads.

With the 610T, we decided to rethink the chassis from the ground up. Unlike previous Reference amplifiers that required abundant floor space and multiple fans for cooling, the 610T is a striking vertical design with tubes projecting above an anodized top plate. Dimensions are 14"W x 22"D x 21"H. The advantages of this design allow easier, next-to-speaker installation, silent convection cooling and better weight distribution. The "tower" chassis configuration (hence "610T") houses three different levels of circuit function. At the lowest level are the power and output transformers; on the second level are power-supply storage and regulation; and on top are the input and output tubes. A ventilated top cover with quiet Pabst fans is optional for CE compliance (these run off a 12V D.C. supply jack at the back of the chassis). Most owners will want to see the tubes in all their glory, and enjoy the benefits of silent convection cooling.

On the front of the 610T is a vacuum-fluorescent, multifunction display screen like that used on the REF3. The screen is addressable either via front-panel knobs, or by handheld remote. A variety of useful functions can be displayed on the screen: seven levels of illumination, including off; bias measurements for each output tube; A.C. line voltage level; logarithmic, scalable power output (0-10, 0-30, 0-100, 0-300, 0-600 watts); and total hours of tube life accumulated.

In addition to its innovative architecture and owner-friendly functionality, the REF610T sets new sonic standards as well. Just as the REF3 preamplifier provides remarkably clear sonic improvements over its predecessor, the REF2MKII, the improvements of the 610T over the older 600MKIII series are just as great, and of a similar quality. Transient speed, dynamic impact, soundstage focus and liquidity of detail are all remarkably improved. You will not have previously experienced a vacuum-tube amplifier capable of this level of resolution and control over any loudspeaker system. From massive dynamics to subtle nuance, solo voice to massed chorus, the 610T will likely never meet a commercial recording it can't handle with aplomb and deliver with musical passion - especially when driven by its Reference partner, the Reference 3 Preamplifier.

This amplifier is creating yet another sensation in the high-end audio world, from the company that saw the beginning of High Definition® in 1970: Audio Research.

Model Reference 610T Specifications
POWER OUTPUT: 600 watts continuous at 16 ohms from 20Hz to 20kHz. 1kHz total harmonic distortion typically 0.5% at 600 watts, below .05% at 1 watt. Approximate actual power available at "clipping" 630 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 POWER BANDWIDTH: (-3dB points) 15Hz to 150kHz. FREQUENCY RESPONSE: (-3dB points at 1 watt) 1Hz to 200 kHz.		INPUT SENSITIVITY: 4.2V RMS balanced for rated output. (24dB Gain into 8 ohms) INPUT IMPEDANCE: 200K ohms balanced. OUTPUT: 4, 8, 16 ohms. OUTPUT REGULATION: Approximately 0.8dB 16 ohm load to open circuit (Damping factor approximately 16). OVERALL NEGATIVE FEEDBACK: 13dB. POWER REQUIREMENTS: 105-125VAC 60Hz (210-250VAC 50Hz) 1700 watts at rated output, 2300 watts maximum, 800 watts at idle, 370 watts standby.		TUBES REQUIRED: 8 Matched pair 6550C Power Output; 1-6550C Regulator; 1-6H30. Regulator Amplifier; 2-6550C Driver; 2-6NIP input, 1-6H30 Follower. DIMENSIONS: 13.5" (34.3 cm) W x 23" (58.4 cm) H x (20.8" (52.8 cm) D. Handles extend 1.5" (3.8 cm) forward and rearward. WEIGHT: 170 lbs. (77.2 kg) Net; Shipped in pairs, 495 lbs. (225 kg) per pair. Specifications subject to change without notice.

Reference 610T Monaural Vacuum Tube Amplifier by Audio Research

Vacuum Tube Power Amplification from Audio Research

The VS55 Vacuum Tube Stereo Power Amp 

The VS55i Vacuum Tube Stereo Power Ampi Vacuum Tube Stereo Power Amp 

The VS110 Vacuum Tube Stereo Power Amplifierhe VS110 Vacuum Tube Stereo Power Amplifier

The VM 220 Tube Mono Blocks
(information to follow soon)

The 150.2 Class-T Stereo Power Amplifier

The 150M Modular Multichannel Power Amplifier 

The 150M is unlike any previous amplifier design you have seen from Audio Research. First, it is based on a truly modular design, with a main chassis capable of housoing up to seven individual power amplification modules, each rated at 150 watts continuous into 8 ohms, 300 watts into 4 ohms. These power modules employ a unique switching amplifier that modulates its frequency with amplitude/power demand - yielding a highly efficient circuit that generates very little heat. It's called a "Class T" design, and it makes the 150M ideal for any imaginable custom-installation application. Further, the modules are a plug-in design that attach internally via multipin connectors, so modules can be added or replaced as needed by a qualified technician.

Each module may be fed with either a balanced or single-ended signal (there are input jacks for both), and each module has a pair of gold-plated 5-way binding posts for outputs. Input impedance is 150k ohms single-ended and 300k ohms balanced, with identical overall gain in either mode. In addition, pairs of modules may be bridged at the factory for four times the output (600 watts into eight ohms, each pair).

Like every other Audio Research power amplifier, the 150M was developed to meet the most challenging sonic criteria. Power supply design and individual module layout have been optimized to yield stunningly musical results whether running two channels or seven. We believe that 150M begs comparison with any solid state amplifier available, and in fact has the important hallmarks of our tube designs: a natural, spacious soundstage, great bass definition and impact, sweetly resolved highs and lifelike musical dynamics. Whether playing back an adventure-film soundtrack or a concert video, the 150M stays composed and natural-sounding like no other multichannel design we've heard. Used with your favorite a-v processor, the 150M produces more musical results with less listener fatigue.

The 150M may be ordered with one to seven power modules installed. Contact you authorized retailer or Audio Research for pricing.

The PH3 and PH3 Special Edition have been incredibly popular since their introduction in 1995 and 1998. It is hard to believe that these wonderful phono stages have been in our lineup, unchanged, for nine and six years, respectively. But with the analog renaissance showing no signs of diminishing, we feel it is time again to advance the state-of-the-art in moderately priced phono preamplification. We are proud to introduce the remarkable new PH5 which will replace both the PH3 and PH3SE.

The PH5 starts with a new package. The full-width 19" front panel's layout is similar to the SP16, with an LED display on the left side and four soft-touch buttons on the right. The buttons control Power, Mute, Mono, and Loading. For the first time in a PH-series phono stage you can adjust cartridge loading to 47K, 1000, 500, 200, or 100 ohms at the touch of a button. And, better yet, the four front panel controls are duplicated on the remote control included with the PH5. Now you can even adjust loading from the comfort of your favorite chair!

The rear panel includes one pair of SE inputs, one pair of SE outputs, a ground post, and a detachable A.C. power cord. Like other recent additions to our lineup, handles are optional at extra cost.

The PH5 is a hybrid (as was the PH3), utilizing a new high-gain, 5-JFET per channel, non-inverting input stage with constant-current stabilization and no overall feedback. New RIAA circuits are patterned after the Reference Phono, with passive high frequency and active low frequency equalization resulting in an improved margin of stability under the most demanding conditions. The non-inverting gain and output stages utilize four 6922 twin triodes. There are high-stability power supplies with four separate regulators for all tube heaters, plate supply and microprocessor logic. And, as you have come to expect from Audio Research, the bandwidth of the PH5 is 0.7Hz to 400kHz (-3dB). Total gain has been increased to 57.5dB, more than sufficient for low output moving coil cartridges when partnered with an appropriate line-stage.

Sonically, the PH5 surpasses the PH3SE in every way. The PH5 has wonderful clarity, making music sound more immediate and simply more there, putting the musicians in your room. Higher resolution is obvious, but so is an abiding musicality. You will hear more little details, with a newfound ability to unravel complex passages and allow simple ones to stand in bold relief. Both macro- and microdynamics are startling, breathing life into the music and making it more exciting, involving, and fun to listen to. Simply put, you will love what this phono stage does for your music.

Control Functions: Power, Mute, Mono/Stereo, Load.
All Functions usable via handheld remote control.

Inputs: SE L & R.

Outputs: SE L &R.

PH5 Stereo Phono Preamplifier by Audio Research

PH7 Specifications:

Audio Research PH7 Hybrid Phono Preamplifier

CD PLAYERS

CD3 MKII Digital Transport CD PlayerCD3 MKII Digital Transport CD Player

The CD3 has been a remarkable success since its introduction two years ago, clearly demonstrating how much musical information is buried in compact discs. In the face of emerging formats, the CD3 has proved that the billions of redbook discs in circulation remain vital in high resolution music systems. So why change such a good thing? Because the MKII retains the inherent musicality of the original while delivering even higher resolution and lower distortion, along with a new, more elegant remote control.

Functionally, the CD3 MKII remains unchanged. The new remote control is a little wider than our preamplifier remotes while offering the same soft textured finish, silver underlay, and ease of use.

Sonically the MKII simply refines the wonderful presentation of the CD3. What will you notice? Higher resolution with reduced distortion, a lower noise floor, and increased micro and macrodynamics. The translation? Lyrics have greater intelligibility. Instruments are better focused in a more spacious and airy soundstage. When things get loud everything hangs together, without glare or harshness, because distortions that crept in previously are now absent. Music simply breathes more freely and with greater authority.

How did we do it? The advancements were made through the careful application of proprietary electrical, mechanical and optical modifications and treatments. In total there are 45 parts changes and additions.

The MKII update will be available to original units as a factory upgrade. The update is very labor intensive, requiring complete disassembly, which makes it impossible to perform in the field. Please contact Audio Research Customer Service to schedule an update.

The CD3 has proven to be one of the most respected, highly-praised CD players available anywhere. Nonetheless, we have been asked repeatedly when we might bring out an even higher-performance, Reference-level model to complement the CD3MKII.

Try as we might, it was not until we had the remarkable circuit of the REF3 preamp that we knew we had the missing link: a gain stage so pure and revelatory that it could finally push CD-player performance well beyond the limits of the CD3MKII. So, we are pleased to introduce the Reference CD7 vacuum-tube player / transport - the first digital product from Audio Research to justify the "Reference" badge.

Incorporating the strongest aspects of the CD3MKII - its rugged construction, the Philips Pro2 laser mechanism, the Crystal 24-bit DAC, its user-friendly menu of useful features and functions - the REF-CD7 breaks new ground with a gain stage taken directly from the REF3, incorporating the latest proprietary capacitor technology found only in Audio Research Reference components. Using four 6H30 triodes, the audio stage features high-voltage regulation using an additional three 6H30s, coupled to a massive power supply.

The extensively ventilated top-load chassis is just slightly deeper front-to-back than the CD3MKII. Height is unchanged to allow a wide range of shelf installation options, while a thicker front panel helps identify the REF-CD7 as a Reference product. Inputs, outputs and the accompanying remote are identical to the CD3MKII. The "standby" function on the CD3MKII is now a power on / off function on the REF-CD7, with an accompanying LED indicator on the front panel.

Given the CD3MKII's reputation for exceptionally musical performance, the logical question might be: "Is the REF-CD7 really that much better?" Yes it is, in every way. You will quickly discover that the REF-CD7 offers a sonic background that is quieter and blacker, thanks to noise and distortion figures that are significantly lower than those of the CD3MKII. Musical dynamics and sheer openness of the soundstage are also much improved, in part due to the massive power supply and carefully chosen parts. But you will also hear dynamic nuances that render small-ensemble recordings much more believable and vivid. Notes and sounds have more individual shape, body and location as they appear and recede. The soundstage expands and breathes as the recording calls for it. Bass response is massive, tuneful and controlled. The REF-CD7 simply has a natural speed and ease without coloration - it is truly like the REF3 in this regard. There is a weight and harmonic completeness one expects from a reference-level vacuum-tube product.

With other digital music formats losing support in the marketplace, we music lovers continue to add ever more redbook CDs to our collections. And what better way to bring those CDs alive than by retrieving their full musical potential and enjoyment through playback on the Reference CD7? With tens of thousands of dollars already invested in CDs, and many more yet to be purchased, it makes more sense than ever to bring out the best in your collection by investing in a CD player that performs musically beyond anything you have previously experienced. This is the heart of what the Reference CD7 is all about.

Reference CD7 CD Player, Audio Research