One even claimed that Audio Research tube power amplifiers in particular, sounded “hard, brittle, and solid-state.” Now mind you, this acquaintance probably hasn’t heard anything that Audio Research has made in the past two decades, but his opinion was absolute. And I’m here to tell you, that “audiophile” was dead wrong.
The VT80 is the polar opposite of those adjectives. No, I’m not going to waste my time trying to change that guy’s opinion; many have the attitude “Don’t confuse me with facts, my mind’s made up!”
So how, exactly DOES the Audio Research VT80 tube amp sound? Read on…
Audio Research VT80 Tube Power Amplifier
- Amazing soundstage
- Voicing is clean with no tube bloat
- Voicing won’t be mistaken for a solid-state amp either
- Surprising bass in the VT80
- Wonderful dynamics throughout the audible ranges
- Comes with amenitie
- World-class construction of the Audio Research VT80 Tube Amp
Allow me the luxury of some hyperbole…
There are two types of audiophiles. My audio amigo, Walter, is one type. When he buys an audio component, he evaluates his needs, does extensive market research on which components fill those needs, takes time to go and listen to the candidates, and then purchases his (carefully-considered) choice. After that, Walt keeps his equipment until it becomes hopelessly obsolete, or until, after years or even decades of service, it is no longer cost efficient to repair.
I, at the other extreme, would be happy to win the lottery and have a new component to play with each and every week!
Of course, most listeners fit somewhere in the continuum between those two extremes. But various manufacturers target different parts of the spectrum. The bottom-of-the-barrel AVR manufacturers, for example, build to a consistent (and consistently low) price point, knowing that their products will become obsolete long before the wear-out phase. Other manufacturers, like Audio Research (you were wondering when I’d get around to them, weren’t you) build components that one can anticipate handing down as heirlooms to their grandchildren while still meeting their original factory specs.
Audio Research was founded in 1970 in Minneapolis, Minnesota by William Zane Johnson, who began designing custom audio electronics as far back as the 1950’s. The company has grown steadily over the last 47 years, with a network of specialist retailers in North America and distributors in Europe, Asia, and South America. The company occupies a 48,000 square-foot production plant and administrative headquarters in Plymouth, Minnesota where about 50 technical, assembly, and support staff are employed.
Audio Research (and McIntosh, currently owned by the same parent company) are “carriage trade” manufacturers who spare no expense in engineering or manufacturing. This would matter little if their products didn’t sound commensurately good. Fortunately for us, they do…
Dimensions (WxHxD) in inches:
19 x 10.33 x 19.4 (including terminals)
75 watts continuous, 7-60K Hz
Single pair of RCA (unbalanced) jacks and single pair of XLR (balanced) jacks
1.4V RMS for rated output (25dB balanced gain into 8 ohms)
300K for balanced inputs, 150K for (unbalanced) RCA inputs
R/L 5-way binding posts for 4 or 8 ohm loads
Non-inverting referenced to balanced input pin 2+ (IEC-268)
112dB (an excellent spec)
THD + Noise:
1% at clipping, typically <0.05% through usable power output
Hum + Noise:
-112dB (measured with no signal, input shorted)
Overall negative feedback:
10v / microsecond
Power on/off – auto shut-off on/defeat – Bal./Single-ended – 12V trigger
Preferred ambient air temperature:
230 watts, idle – <1 watt, sleep – 410 watts, rated output
120 or 240 Volts
Two matched pairs of KT-120, Two 6H30 drivers
MSRP Audio Research VT80 Tube Amp:
Audio Research, VT80, Stereo Power Amplifier, Tube Amplifier, Power Amplifier Review 2017
LINKS TO OTHER POWER AMPLIFIER REVIEWS ON THE SECRETS SITE:
The chassis size and shape of the Audio Research VT80 meet my ideas of what a tube amp should be. The power switch and pilot light are on the front panel, the tubes are spaced sufficiently far apart from one another and from the transformers to avoid heat build-up, and the rear panel is clearly labeled with terminals sufficiently spaced that even the largest speaker wires can be safely and easily installed.
If the VT80 were a house, I’d say that it had a full complement of amenities. Those include:
The amplifier uses a solid-state rectifier for its power supply rather than the more common rectifier tube. In addition to being more efficient with lower impedance, the solid-state rectifier won’t age as a rectifier tube would, and is much more reliable. When the VT80 is powered-up there is a 30 second auto-mute cycle to allow the circuitry to stabilize properly, and there is a low-line-voltage sensor that automatically mutes the amplifier should the supply voltage drop below 95V.
The VT80 is the first Audio Research amplifier with a new auto-bias circuit that monitors all of the output tubes. Their electrical characteristics change over time and the bias may become out of kilter. This seriously degrades the sound of the amplifier because the positive and negative sides of the audio waveform are being amplified at different rates of gain. Audio Research’s auto-bias automatically monitors the tubes and adjusts the bias of each to ensure that no sound degradation occurs. Most tube amps must be manually re-biased on a periodic basis. If you happen to be sufficiently tech-savvy in the use of a multimeter and screwdriver, this is not a challenge. But for the average audiophile, the results are what count, and the VT80 delivers the music without any need to futz with the equipment.
The microprocessor is also available to automatically shut off the amplifier after a period of time. That way, if you leave for work, forgetting to turn off the amp, it shuts itself off, saving both electricity and tube life. Don’t want the auto-shutoff? It’s defeatable via a back-panel toggle switch.
The chassis, in addition to being generously sized, has ventilation holes around the periphery of each and every tube. This ensures even and effective cooling for the tubes and lengthens their service life.
If you prefer, you can use the 12-volt trigger from your preamplifier or processor to turn your VT80 on and off. Most tube amps lack this concession to the 21st century.
The ability to use either unbalanced (RCA) or balanced (XLR) inputs is also a convenience, ensuring that the VT80 will work with any other equipment you may choose.
And, should something go wrong with the amplifier despite the internal controls, each tube has its own individual fuse. This means that if one of them fails (either from internal fault or because you dropped something on it and it broke), the resulting voltage surge won’t damage any other tubes. This is such a fundamentally great idea that I fail to understand why other tube manufacturers don’t do it. It’s SO much cheaper to replace a fuse than a tube…
Yet another neat amenity is the “HOURS” display on the rear panel that shows you how long your tubes have been in service. This does away with the question, “Is it time to replace my tubes yet?” The rear panel also has an RS-232 port that can be used with an automated control system, such as Crestron.
Audio Research ships the amplifier with Russian KT120 tubes, but tube-rollers may opt to use any of the following instead: 6550, KT88, KT90, or KT150. And while we’re on the subject of tubes, the KT120 has a reputation for having strong bass and slightly less treble than the more common 6550. I haven’t heard any KT88 amps in a long time, so I couldn’t comment on that. I’ve also yet to hear the KT150, since it’s a relatively new (and expensive) tube. Suffice it to say, though, that if the VT80 amplifier sounds too strong in the bass for your speakers or your room, a simple change to the (less expensive) 6550 tubes should balance the sound for you.
This isn’t to say that there’s anything wrong with the stock tubes – In fact, I think I prefer the lovely KT120 tubes when running any of my speakers sans subwoofers. The KT120’s bass heft makes even modest speakers sound stronger and lower in their bass ranges. And just because the KT120 tubes don’t give a sparkly treble, don’t think that their treble is weak either. In short, I think the KT120s were a great choice for this VT80 amplifier!
Audio Research’s “out of the box” experience begins with the VT80’s packaging. Care was taken to ensure that it was effective in preventing shipping damage. The tubes arrive in a small box with custom-cut foam surrounds. The driver tubes arrive with anti-vibration rings.
Just plug in the tubes; they’re individually labeled to indicate which socket they belong in and are also keyed to go in only one way, so you can’t mess it up. There is no bias to set since the amplifier’s auto-bias circuit handles that chore. Hook up the speakers and inputs, turn it on – and the amp is functional.
All tube amplifiers produce generous amounts of heat; therefore, ventilation is important. This amp should not be set directly on carpet, for example, because the carpet will block the airflow through the chassis. Place the amplifier on a hard surface with plenty of vertical clearance above it.
Additional equipment used for this review included
- jRiver Music server 22 for Mac
- WAV files ripped from CDs
- Some SACD high resolution audio discs
- Oppo BDP-105 connected via DLNA and (sometimes) used as a DAC / Preamp
- Apple Airport Express as a listening room WiFi source
- iPad mini running jRemote as a system controller
- Emotiva BASX PT-100 preamplifier with DAC
- Vacuum Tube Audio ST-120 tube power amplifier
- Crown PSA-2 solid-state power amplifier
- Heathkit hybrid 12-watt monoblock tube amplifiers
- Tekton Pendragon tower speakers (8 ohms)
- Axiom M100 tower speakers (4 ohms)
- KEF LS-50 stand-mounted speakers (8 ohms)
- BlueJeans Cable interconnects and speaker wires
- Nordost Flatline speaker wires
- Audioquest interconnects and speaker wires
- Emotiva power conditioner
- Room treatments by ATS acoustics
- NOTE: No subwoofers were used in any part of this review
This is an opportune time to mention equipment-matching; specifically, the amplifier-speaker interface. A ludicrous contention has grown in some audiophile circles that “there’s no such thing as too much amplifier power.” This misconception arises from the claim that transients require significantly more power than the averaged program material. The fact of the matter is that virtually everyone listens to their stereo at one watt or (usually) less amplifier output. The Audio Research VT80’s 75 watts per channel is more than sufficient for normal listening in normal sized rooms. It wouldn’t be the ideal amplifier to power a football stadium, but some feel that more power is (always) better power. That’s absolutely wrong.
The “never enough power” philosophy leads to absurdities such as 1,000 watt monoblocks driving highly sensitive speakers. You can do this, but it isn’t the right tool for the job.
The VT80 is suitable for any modern speaker. Modern speakers, by my definition, have sensitivities of nearly 90 dB (1 watt/1 meter) or higher and impedances of 6 ohms (nominal) or higher. If you have a speaker of significantly less than 4 ohms impedance, or one that is in the low 80s in sensitivity, you may want a different amp.
The VT80 revealed some ground loop issues in my system that I’d not been aware of before. This isn’t a bad reflection on the amp, but rather on the fact that my system had issues I was only intermittently aware of until the VT80 showed them to me. Once the AC grounding was sorted, the issue disappeared.
Immediately out of the box, I was struck by how dynamic and dimensional the amplifier sounded. The amp exhibited a very deep and wide soundstage. The manufacturer describes it as “holographic,” and although I wouldn’t go that far, I will say that I’ve only ever heard one amplifier pair that did better.
And since someone’s bound to ask, that “better” amplifier was a pair of 12-watt Heathkit monophonic integrated amps that I completely rebuilt into monoblock power amplifiers. But my Heathkits, despite very slightly bettering the VT80 in dynamics and soundstage, are wildly uneven in frequency response.
The VT80 gives all but a smidgen of the Heathkits’ dynamics and soundstage while providing literally an order of magnitude smoother frequency response. And, the VT80 provides 75 watts per channel to the Heathkits’ 12.
The VT80 IS the best amplifier in the bass range that I’ve heard in my room. Is it because my speakers like the transformer output? It may be, but with three different sets of speakers, the VT80 came out the consistent winner for bass depth, drive, and articulation (with one exception mentioned below). I have several other tube amps with output transformers that can’t do bass like the VT80.
Are the VT80’s compliment of Russian KT120 vacuum tubes the source of the amplifier’s wonderful bass? They may well be a big factor. One of my other tube amps uses 6550 output tubes, but it lacks the bass of the VT80. Would my other tube amp “bass up” if I used KT120 tubes in it? Maybe…
I also have a ginormous Crown PSA-2 solid-state power amp in the house with 375 watts/channel AND a damping factor of >700 from DC to 20kHz. If the spec-meisters are to be believed, the Crown should make the woofers sit up and beg. But it doesn’t! The PSA-2 sounds slightly mushy in the bass while the VT80 rocks the house. So much for specs – and so much for those who believe that specifications are the sole measure of how a component will sound. It just isn’t so.
An interesting thing happened when I hooked up the VT80 (using its 4-ohm output taps) to the 4-ohm Axiom M100 speakers. The generous bass that I heard with the Tekton Pendragons was still there, but the bass articulation was now somewhat reduced. The VT80 and the Axioms just didn’t sound as crisp and articulate in the bass as the same amp had with the Pendragons. Now I know that the Axioms CAN do highly articulate bass, and have heard it with other amplifiers, but with the VT80, not so much. I wouldn’t necessarily blame the amp for this one though – amplifier/speaker matching is as much an art as a science.
What I did hear with the M100s and the VT80 that I hadn’t previously heard from the Pendragons was a midrange to die for. The imaging depth and width had been excellent with the Pendragons – I didn’t think there was any farther the music could go. Wrong. With the VT80 and the Axioms, Paul Simon’s voice was IN THE ROOM and the array of backup singers, percussion effects, and support singers was spread over a wide, clearly divided, and highly articulate sound stage of amazing width and depth.
Now I wasn’t there when Mr. Simon’s music was recorded, so I can’t say how true to the original recording this aural display was, but the soundstage was startling. That’s the best word to describe it – startling.
Just for fun, I put on Madonna’s “Vogue” from her “Immaculate Collection” CD. Regardless of what one might think of the music, the Q-sound recording is an amazing tour-de-force of what’s possible in audio recording. And although I’ve heard the track sound “wall-to-wall” wide with previous setups, the Axioms and the VT80 gave this track the most spacious presentation that I’ve ever heard. Stunning.
I’ve mentioned the dynamics of the VT80 and one of the albums that showed the dynamics best is the Smetana/Dvorák CD by the Guarneri Quartet (Phillips label). The instruments are vivid and jump out from the stage, as they do in a real (small venue) performance. I’ve had the pleasure of hearing live chamber music in my home and in the homes of others, and this seems to be as close it gets (in a recorded version) to what I hear live. But not all systems can make even a good recording sound “live.” My system (in any previous iteration) hasn’t awakened this music as did the VT80.
Now this brings up several associated comments. My acquaintance who dismissed the Audio Research amplifiers as sounding cold and solid-state hasn’t heard this amplifier. The VT80 isn’t as generous with “tube glow” as are the classic amplifiers from Dynaco, etc. If you want that level of romance, buy a classic tube amp and be done with it. But the VT80 seems to have the very slightest tube bloom in the vocal range (incidentally where most of the orchestral instruments live, as well). This “presence bloom” gives solidity and weight to vocals and instruments without being noticeable unless you’re specifically looking for it. If the amp were measured into a resistive load, I’m sure it would measure ruler-flat, but what I hear is certainly there. Is it an artifact of the amplifier-speaker interface? I think not since I played the amplifier through three different speakers and heard the “midrange bloom” in each. But it’s subtle enough that there’s no noticeable coloration to the sound – it just sounds both right and present.
If you’re used to solid state amplifiers, you’ll probably notice no frequency issues with the VT80, but you will (and immediately) notice the expanded sound stage with its additional width and depth. My comment to a friend was that this amplifier makes digital recordings sound analog. And that was meant as a compliment. This was even more so with the lovely KEF LS50 speakers. Being point-source radiators, they took the VT80’s imaging (already excellent) to yet another level.
The treble of the VT80 is just fine – not bright, not shy. But that isn’t what many so-called “audiophiles” want. They want sparkle – they want “air” – in other words, they want treble like nothing ever heard in real life. If you’re one of those folks, the VT80 probably isn’t for you. The best description I can give of the VT80’s treble is “natural.” And, most important to me, the VT80 gets the balance right on cymbals. Maybe my ear is just sensitive to that frequency range, but I find that many recordings (and many speakers) give insufficient weight to the brass sound of cymbals while emphasizing the overtones. To my ears, the VT80 gets it right.
So bass, treble, midrange, and dynamics – the VT80 has it all. But with the very best speakers, the VT80 does something else that very few other amplifiers can swing, it makes the music sound like an organic whole from the top to the bottom of the frequency range. This elusive “cut from the same cloth” effect is the difference between listening to a recording that sounds like real music and the artificial reproduction of same.
I’ve written before about how the human ear can intuitively decide (and instantaneously) whether music is live or reproduced. The example I use is of walking down the street and hearing music from one or two blocks over. Despite the traffic and street noise, the brain knows, and within milliseconds, whether that music is live or recorded.
Music reproduction equipment can’t yet pull off that illusion, but the best equipment (including, specifically, the Audio Research VT80) is getting closer. My wife, whose opinion of audio gear is “it all sounds the same,” would frequently migrate into the living room when the VT80 was playing to listen with me. That’s a telling metric of how natural the VT80 makes music sound.
Since I have no electronic test equipment but a multi-meter, I could not measure or verify Audio Research’s specifications.
However, I did run some frequency sweeps to see how the speakers were behaving. Suffice it to say that the VT80 supplied a flat, in-room frequency response equal to what I’ve heard from any other amplifier; which is to say that the room (as always) has a greater effect on the sound than the speakers OR the amplifier.
With the high-quality parts in the VT80, and with its thoughtful tube fuses and microprocessor control, I’d expect amazing reliability. Nothing in the design or construction leads me to believe otherwise.
THE AUDIO RESEARCH’S VT80 TUBE AMP is among the best in class and a top pick at $8000, or any price for that matter.
- Imaging and soundstage
- Bass response and control
- Great design implemented with premium parts
- Ability to tube roll (although I can’t imagine why you’d want to)
- Lower price (but I can understand why it’s priced as it is)
This is a frustrating component for me to review. The Audio Research VT80 is, in most ways, the very best power amplifier I’ve ever heard. I’ve previously owned Audio Research tubed amplifiers (D40), McIntosh tubed amplifiers (MC240), and McIntosh transformer-coupled, solid-state amplifiers (MC352), and although all sounded excellent, none matched the bass extension/control or soundstaging of the VT80.
And it needs to (again) be explicitly stated (although it should be intuitively obvious), that above a certain price point, audible improvements are not only incrementally smaller but also exponentially costlier. If you’re expecting the VT80 to be four times as good as the best $2,000 amplifier, you’re doomed to disappointment. But the fact is indisputable that (to my ears) the VT80 is audibly and immediately superior to any $2,000 amp I’ve ever heard. So is the VT80 worth its $8,000 price? That is a decision you’ll need to make.
If you’re like my friend, Walter, who buys quality, and then keeps it virtually forever, the amortized “per year” cost of the VT80 becomes insignificant. However, it bears saying that the majority of us won’t ever be in the market for an $8,000 amplifier however good it might be. But before you make that decision, and if the price is even remotely affordable to you, find an Audio Research dealer and listen to this amplifier. Given its extremely high-quality construction, amazing sound, and consistently high resale value, you might just change your mind. Before you spend any fraction approaching 50% of the price of this amplifier, you owe it to yourself to at least hear the Audio Research VT80 tube amp. It’s that good.