Review: Audio Research Ref-3 Tube preamp

Category: Preamps

My wife calls me a luddite--someone who only begrudgingly adopts newer technologies. I like to consider myself circumspect, not one for the flavors and fashions of the moment, I choose to commit to things proven through time. And why not? Wasn't it the relentless self-serving promotion that cursed us with digital and nearly killed a clearly superior vinyl format? I've always felt that audiophiles are victims of this promotional phenomenon...that the 'next great doodad' is going to suddenly catapult Sinatra into the room. Folks, it ain't happening; such promotional efforts are designed to sell products, and that's fine if one knows it going in. But, that's not to say that the "latest and greatest" is the cure for all ills, nor is it to say that yesterday's linens smell any less fresh.

That takes me to this review: the Audio Research Reference 3. I believe the unit I bought, 2k hours on tubes, was made in 2006 and reflective both electronically and mechanically of units which were covered in reviews circa 5 years ago. Since then, Audio Research and the reviewing press have moved on to their new puppies, as have numerous owners. But no harm in take one more look at yesterday's darling, which current wags would have you think is chopped liver.

It most certainly is not.

A bit of background on the unit: its large, kinda clunky looking, and with a display that my 85 year old grandma could read from across the room---thankfully it can be switched off via the remote, which is also required to get the best sonics out of the unit (with the display on and mute engaged, the unit makes a high pitched whine; just dim the display or remove mute and this noise goes away). Ergonomically, I'm absolutely thrilled with this unit. It comes up to its sonic peak within an hour as the tubes warm up. Six inputs (plus HT Bypass) are available, with each having provisions for either RCA or balanced---the user simply assigns the type connection for the named input, and the preamp stores in memory. That said, the unit is fully balanced and sounds best when up and downstream are balanced as well. Dual main outputs, along with a home-theatre bypass, send the signal downstream. Additional points of interest: remote controlled volume, source selection, mono, mute, HT bypass, phase and balance (which I find very handy in a less-than-symmetrical room). The volume control is some sort of laddered resistive element (not the lousy mechanical wipers found in potentiometers), with a numerical display of the volume setting to permit easy comparisons, and the steps between the settings (1 to 100) are so slight that one can always find the right volume setting. I couldn't ask for anything else in a remote (its also small, uncluttered and made of plastic--its a classic remote design)

The unit comes with a 20 amp cord, which many folks say sounds just fine, and it does. Its just that when I inserted a TG Audio cord (with 20a IEC), I noticed that the upgraded power cord provided for more space around performers, and a soundstage that seemed to get 2 feet taller. The stock cord was more congested in the midrange in comparison, and did not have the top or bottom end extension as the aftermarket cord. So, for folks wondering where to go if interested in an upgrade, start with the power cord.

One other thing: the tube circuitry requires an amplifier having an input impedance north of 20k ohms; be forewarned, else you'll just be giving up dynamics and bass depth unnecessarily.

Onto further listening impressions:

Let me just come out and give you the 4-1-1: if you like what SET amps do for sonics, you'll like this preamp. If you object to what SET amps fail to do, then you'll find the same objections with this preamp. To elaborate: I once owned a Wavac SET amp which I had mated to Wilson loudspeakers. While it would run out of steam and harden when pushed too hard (something the Ref 3 never did), it still had some defining characteristics which I found similar to those of the Ref 3. Namely, the unit did wonders with digital playback, adding a romantic coloration in the mids / presence region that was inviting, seductive, and (depending on the recording) excessive. An electric guitar would have a bit less bite, while Sinatra sounded like he had one too many rather than his studio best. Its always an enjoyable and musical sound, one which is never going to cause listener fatigue, but lets not kid ourselves and think this is absolute fidelity to the master tape. Its a slightly-enhanced version, but these enhancements make it sound more rich, musical and inviting. But when you think about it, most digital-source systems would be well served to have more richness and more musicality; the ARC, like a SET amp, is a great choice for offsetting the problems endemic in digital-based systems (which typically suffer from being flat and with a tonality biased to the cool side).

Bass in the ARC is not surprising given what it is: it has a big tube power supply (6550c), and thats what it sounds like. Bass depth is considerable, while being overly generous and round. While I sometimes like to listen to dance music with its fat bass, I don't want the preamp to fatten it up further, which the ARC does---but not to the point where the music loses definition in the mids, nor is it so bad that it sounds like a 12 year old set up the subwoofer. Pitch is quite good, but bass (not midrange) definition is lost due to the lingering nature of the bottom octaves. This also has the net effect of slowing down the pace of the music; this grievance was not so great that a drummer listening to the preamp would've barfed, but he also would've thought the timing of most every track was just a fraction slow. I've heard recordings of bands and other preamps where I felt the term "relentless" was appropriate (in a muscular, urgent, and inspiring way); the Ref 3 was not a relentless preamp, and I suspect hard rocking audiophiles (and drummers) would likely be able to find better choices.

Dynamics are quite good and sound as good as I've heard a tube-based power supply provide, but there's no pretending the Ref3 has dynamics to match a great SS preamp. Two other preamps that I've owned, the Edge NL and the Einstein, both had considerably more force and explosiveness than the Ref3, and both relied on different SS topologies: the Edge used batteries, while the Einstein used dual transformers in a SS circuit biased to class A (along with the gain stage occurring before the volume control). While the Ref3 didn't disappoint, it also didn't pin me back in my chair like these other reference preamps could.

Like the Wavac, the Ref3 does wonders with space: extending the boundaries of the soundstage, placing musicians on them in their own space with defined depth and density. I believe this is part of the magic that tubes provide, as I've not heard SS circuits equal tubes when it comes to space. Ultimately I think this is because of the type of noise floor, with a tube-circuit noise floor doing less damage to the signal, while a SS-noise floor can attach itself to the midrange and treble; again, this is just a theory, but tubes do sound different in some very important ways, soundstaging being one of them.

Due to the very low noise floor of the unit, lower than most any tube preamp (with tube power supply) I've come across, dynamics did emerge from a deep dark background. The other benefit of the noise floor is that microdetail retrieval was exceptionally good (that’s the thing about noise floors---every time they get lowered, you get closer to the recorded event). Whether it be pitch fluctuations in the human voice, the ringing decay of an acoustic guitar string, or the cankling of background noise in a live recording, the Ref3 did a wonderful job of putting it into the room, without any false spotlighting or leading edge highlighting. While I've heard more detail from a few preamps, particularly in the upper treble (where cymbals and piano did miss a bit of shimmer and ultimate top end extension), I never had the impression that the Ref 3 was robbing me of anything.

So far in this review, I've covered more about what I don't like, rather than the unit's strengths. Well, its worth knowing what the unit does wrong up front, as what it does right, namely with midrange presence and tonality, is so obviously the defining characteristic of the unit that I consider it self-evident. The listener does not need to tube roll, get fancy footers, or get an aftermarket power cord (though all those things help) in order for midrange tonality to sound natural. And this, dear reader, is where our ears are most well-trained, as this is the frequency area where we've focused our hearing throughout our lives. I dare say I've not heard a preamp in my system, perhaps other than the Herron VTSP-3A, that does a more natural and believable job with the human voice (but the Herron couldn't keep up due to its elevated noise floor and dynamic limitations). If anything, the Ref 3 has a bit more presence and warmth than reality which is pervasive from treble to bass, but just a bit, and again it does so in a manner that invites long listening sessions and enjoyment. But, much like a SET amp, it’s a bit more warmth and glow than reality, and those listeners who are absolute fidelity types would sense this ‘sin of commission’. I doubt many listeners will object, particularly those whose systems revolve around compact discs; analog-based systems with warm front ends might, however.

When taken together, this darling of yesteryear still provides a very musical and satisfying performance, and that doesn’t change with the turning of the calendar. Its connectivity and ergonomics are a delight and will accommodate all but the most complicated of systems, and its flaws are such that they can be forgiven in the context of long listening sessions and a midrange that has a sense of rightness about it which even an untrained ear will agree with. While well off the pace from today's best in areas like dynamics, bass definition, extension and pace, it still does these things well enough to satisfy the most critical of listeners, and can find a home in most reference systems for a lifetime.

Tracks under comparison:
David Bowie: “Queen Bitch” off Hunky Dory
The Hold Steady: “Citrus” off Boys and Girls in America
The Bird and the Bee: “Polite Dance Song” off Ray Guns are Not Just for the Future
Jack Johnson: “Cupid>Wasting Time” off On and On
Lyle Lovett: “Church” off Joshua Judges Ruth
Sinatra: "I've Got You Under My Skin" off Sinatra at the Sands

Associated gear
Click to view my Virtual System

Similar products
Herron VTSP-3a
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Excellent review, Rhyno. It would be interesting to see how the Ref 3 performs with rolled in tubes. With my CAT, rolling in tubes was a very big upgrade, increasing dynamics, firming up the bass, and considerably opening up the soundstage. I wouldn't be at all surprised if tube rolling would do the same thing for the ARC.
Ditto Daveyf -- ecellent and detailed review. I used to own the Ref 3 and loved it. The only reason I upgaded to the Reg 5 (and soon to be Ref 5 SE) was ungraditis. I think the Ref 3 will go down in audio history as a true classic that will please for years to come.
Rhyno - What output caps are in the unit you have? Are they original?
Great review BTY!
Just so you know that are other SET amps that are not romantically colored in the mids like the Wavac. Coincident, Absolare, Lamm, and Audionote of Japan come to mind.
This pre is not for tube rollers. The 6H30 tube is only made by one manufacturer.
Excellent review. I'm the original owner of a REF-3 and I totally love it. Here's a tip for ARC owners of the equipment that uses the tube dampers ... Move the dampers as far up the tube as possible without the top damper coming off. Be sure that both dampers are touching each other. Try to make each set of dampers the same on each tube. Try it ... its a significant improvement without any cost.

You're welcome. :>)
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Common for aging preamps.  You can send it in to Audio Research and get fleeced or get an honest competent tech to check the tubes and B+.  If both channels wheeeeee and you swap the tubes from left to right channel and it stays the same then the power supply caps have deteriorated to the point where you need replacing them.  This is an artifact of the high feedback regulator oscillating when the cap bypassing its output fails.  Electrolytics are cheap and easy to replace.  
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The OP's take on the Ref 3 mids, treble and soundstaging is all in agreement with my own Ref 3.  However I do not agree with the overall assessment by the OP regarding the Ref 3 being even a bit too warm or bass heavy. If anything I would crown the Ref 3 "the tube preamp that exhibits absolutely ZERO BLOAT."  

However there is a catch.  While all the bloat is gone and I mean GONE (along with noise by the way) it took with it a fair amount of the power in the mid bass!  This is particularly evident in the hammer strikes of a grand piano being dull and not percussive.  The effect adds great clarity to the frequencies above and below the notch out (which I believe is around 100-400hz).  But it is a notch out for sure---and if I have the story straight it is a bit deliberate---as the previous Ref 2 was deemed a bit sloppy in the bass.


My own Ref 3 needed speaker repositioning and some bass tweaks in my subs to hit it perfectly and now the "hole" is much less in evidence.  Grand pianos again sound grand instead of sounding like spinets.  But not everybody can tune their speakers to the preamp timbre tonality bias.  I got lucky.


Anyway this is one great design especially once you make the most of its response curve by working with its bias.  It is not really "lean" so much as the bloat frequencies are a bit hollowed out.  And as I say you can make that work to your advantage once you get hip to what is going on.  I did.  At this point I can not imagine a better sound per dollar than the approximately  five grand I have in my mint second owner unit (new tubes etc).  Harmonic beauty, immense soundstaging that defies belief and three dimensional holographic images so precise you can measure their size to the inch!  Amazing!  This quality of sound reproduction simply does not exist at my earlier price point but now the Ref 3 on the used market seems to my mind a true bargain---IF you tune to its strengths.


Has someone upgraded the 6550 to KT-120 power tube on Reference 3 preamp ?

How did it sound ?