A Preamplifier Faceoff: Ayre & PS Audio

In the March 2018 issue, Art Dudley admired the sound quality of Ayre Acoustics' KX-5 Twenty preamplifier, but didn't love some of its operational aspects (footnote 1). I've staged this Follow-Up as a putative face-off between the Ayre and my current reference preamplifier, the PS Audio BHK Signature, which I reviewed in the June 2017 issue (footnote 2).

Although the PS Audio BHK Signature and Ayre KX-5 Twenty preamplifiers have some things in common—eg, both are fully balanced and have both XLR and RCA outputs, not to mention the fact that both products are made in Boulder, Colorado—their prices were arrived at from opposite directions. At $5995, the BHK Signature isn't just PS Audio's current flagship preamp: it's one of the most expensive components the company has ever produced. But at $9950, Ayre's KX-5 Twenty is a result of trickled-down technology: Ayre introduced its Variable-Gain Transconductance (VGT) volume-control circuit in the KX-R preamp, which at the time cost $18,500; the current, updated version, the KX-R Twenty, costs $27,500. Is it better to benefit from trickled-down technology, and settle for less than a company's best—or experience the purest expression of a company's audio vision?


I decided I would compare the two preamps using a single recording: Saint-Saëns's The Carnival of the Animals, with pianist Martha Argerich, and Antonio Pappano also playing piano while conducting a chamber ensemble drawn from the Rome Santa Cecelia Academy Orchestra (CD, Warner Classics 0190295755553). I'd been listening to this excellent-sounding album for a couple of weeks—to the MQA version on Tidal, via Roon—when I saw Robert Levine's review in the March 2018 Stereophile. With its disc-mate, Saint-Saëns's Symphony 3, "Organ," Robert awarded the recording 4.5 stars for the performance and full marks—a rare five stars—for sonics. "Stunning!" he concluded. Full of contrasting instrumental timbres and colors, Carnival makes a good audition piece—and while it may be children's program music, I like it!

First, though, I had to match levels. I began with my PS Audio BHK Signature preamp, setting it to a level that seemed natural for the music. Then I played a white-noise track, and measured the output with a digital meter: 79.2dB, with the BHK's volume level set to "40" (in a range of "00" to "100"), as indicated on the preamp's digital readout. Then I moved the interconnects over to the Ayre and played the white noise again, adjusting the volume level until it matched the PS Audio's as closely as possible. The best I could do was 78.5dB, with the Ayre's volume set at "30" (out of "46"), so I moved the BHK's volume control down a click, to "39." That put the volume at my listening chair at 78.6dB—just 0.1dB louder than the Ayre. That's good volume-matching. In the ensuing comparisons, I kept my paws off the volume control.


Subtle differences emerged immediately in Carnival's first movement, Introduction and Royal March of the Lion: just past the 30-second mark, when the two pianos play octave runs at ff, the first piano ascending as the second descends. The engineers seem to have taken the recording level right up to the edge of the red. Through the Ayre it was loud, intense, percussive, even noisy—the last not a fault of the preamp, but clearly intended by the engineers. The PS Audio preamp softened the transients just a touch, slightly polishing the edges. There was nothing polite about the sound; it was just more polite.

The two pianos dominate Carnival's first several short movements, sometimes in combination with various solo strings. Through both preamps the pianos sounded as they should, their natural percussiveness in the higher notes balanced against resonance in the bass and a good sense of the surrounding acoustic. The Ayre revealed a touch more of the pianos' percussive leading edges. The strings buzzed viscerally.

The fifth movement, Elephants, is a short (1:28) demo-quality track, the pachyderm portrayed by Libero Lanzilotta's bowed double bass, sounding rich, fat, and buzzy, with a woody resonance (from the bass's body) that's more audible on some notes than others. Between 30 and 60 seconds in, Lanzilotta plays a lovely legato passage, with subtle dynamic shadings—a little softer, then a little louder—before returning to the main staccato figure. It's one of those communicative moments—not profound, perhaps, but moving in a simple, human way that connects the listener (in this case, me) to the music. There's a shift from hearing a recording to experiencing a human musician playing an instrument. I'm probably in good company when I say that this is why we listen through good systems. That elephant may be big, but while the playing is impeccable, the player seems exposed, even vulnerable.

Speaking of exposed: This bass/elephant exposed the most obvious difference I heard between the two preamps, though it still was quite subtle. The Ayre's sound was drier than the PS Audio's: more rosin, less wood; more core, less body. I could describe this as the PS Audio's sound being a little wetter. Both perspectives are legitimate, and I don't know which is more "correct," more neutral. I used to think neutrality was a meaningful notion. I still think it's useful—indeed, essential—as an abstract objective, but as an empirical goal it's problematic: How do you decide what a collection of bits actually sounds like?


In Fossils, Saint-Saëns recapitulates a trick he'd played 12 years earlier, in Danse Macabre: using xylophones to evoke rattling bones (footnote 3), even as he introduces shreds of familiar melodies, from "Au clair de la Lune" to "Twinkle, Twinkle Little Star" and a famous aria from Rossini's The Barber of Seville. (There's a musical joke here: Saint-Saëns equates those tired melodies with old, buried bones.) The xylophone carves out a big soundstage, wide and deep. The prize for depth goes to the Ayre—the PS Audio's space was ever so slightly flatter—but both preamps performed well. Again, the difference was small.

If the mid-18th-century folk song "Au clair de la Lune" was a fossil in Saint-Saëns's time, his The Swan is a fossil in our own. But it's a pretty melody, here expressively performed by cellist Gabriele Geminiani in excellent sound. Two delicate pianos define a big space, the cello planted between them. The cello is recorded more distantly than the double bass in Elephants, with less body and more room sound. This, for me, was a reminder that perfection in audio is often about balance, not extremes—not the ultimate in buzz or honk, but a natural balance of timbres and natural distance. Here, that balance was nearly ideal through both preamps, but with a slight difference of perspective: The Ayre carved out a slightly deeper space, while through the PS Audio, paradoxically, the cello seemed farther away. The Ayre's reproduction of space was, I thought, a touch more realistic, but this was something I could hear only in a direct comparison.

Both preamps were exceptionally quiet. The sounds of both were vivid, with lovely, rich textures. Both delivered weighty, solid bass. The PS Audio's bass was subjectively a touch stronger, but again, I don't know which was closer to what's buried in this recording's bits.

The sounds of the two preamps were, overall, more similar than different, but if you're choosing between them, there's much else to base a choice on. First, the BHK has two tubes, in its input stage. These can be swapped out with other variants to subtly tune the sound—but tubes also wear out over time, degrading your system's performance imperceptibly, day by day, until audiophile friends who drop by for a listen start giving you odd looks. Tubes are fun to play with. Tubes are unpredictable. Tubes are tubes.

As for controls and logistics, the PS Audio gets the nod. The BHK's innovative volume control has finer steps—roughly 0.5dB—than the Ayre's innovative volume control (1.3dB, as measured at my listening chair with white noise). Indeed, increments of 1.3dB are coarse enough that I had difficulty finding the appropriate volume for some recordings. The BHK has five inputs, each with balanced (XLR) and unbalanced (RCA) connectors. The Ayre has separate balanced (four XLR) and unbalanced (two RCA) inputs; if you've got three unbalanced sources, you're out of luck. The Ayre, though, has the nicer volume knob: it's nice and smooth, and feels better than the BHK's haptic-feedback design (footnote 4).

Ayre's preamp lets you adjust input levels for each input individually, offsetting especially hot ones so that you don't hurt your ears when changing inputs. You can't do that with the PSA. To change the BHK's balance, you must dig into its menu system; there's no front-panel knob. The Ayre doesn't appear to have a balance control of any kind.

Most XLR connectors—including those on the BHK—lock in place. Technical advantages aside, this is one of the reasons I prefer balanced interconnects: stick 'em in, hear 'em click, push a button to remove—no struggling with too-tight RCA connectors. But the Ayre's balanced inputs don't lock, and I think I know why. Three of the Ayre's balanced sockets are arrayed in a column and are only 1/8" or so apart—not enough space, I think, for the little metal levers you press to release an XLR plug. This is not a performance issue—I never had any problem with loose connections on the Ayre, and wouldn't expect to—but small things like this can affect pride of ownership.

The remote controls are quite different. The Ayre's is made mostly of black-painted metal, with some plastic; it has good heft, but a cheesy decal on the front (ANALOG and DIGITAL labels and Ayre's logo) that, over time, bubbles around the buttons (footnote 5). The Ayre remote's layout is simple and easy to use, but it's not backlit. The PS Audio's remote is backlit; it has more plastic, but its textured-aluminum faceplate is nicer, with printed-on labels. The BHK remote is more complicated, though, with controls for a transport, a DAC, and a preamp. Whatever. I'm sure you'll quickly adjust to either one.

Which would I choose? I already own the PS Audio, so I don't have to. The BHK Signature is a great preamplifier, honest and musical. But if I'd instead auditioned the Ayre Acoustics KX-5 Twenty and bought it, I'd probably be just as happy, if slightly poorer—the BHK Signature preamp costs $3995 less than the KX-5 Twenty. That's real money.

Footnote 1: Ayre Acoustics, Inc., 2300-B Central Avenue, Boulder, CO 80301. Tel: (303) 442-7300. Web: www.ayre.com.

Footnote 2: PS Audio, 4826 Sterling Drive, Boulder, CO 80301. Tel: (720) 406-8946. Web: www.psaudio.com.

Footnote 3: In Danse Macabre, it's card-playing skeletons; in Fossils, the bones of dead animals.

Footnote 4: One annoying thing I noticed about the BHK after writing the original review: If you turn the volume knob very slowly, the volume doesn't change at all.

Footnote 5: This appears to be the same model of remote control that Benchmark Media Systems provides with their DAC3 HGC D/A converter ($2195). Its decal, too, is bubbling.

Ortofan's picture

... don't stop now.
Next, could we please have a faceoff comparison between the PS Audio BHK Signature and the Parasound Halo P5 (https://www.stereophile.com/content/parasound-halo-p-5-21-channel-da-preamplifier) - because $4,900 is "real money", too.

EricAnpin's picture

I have listened to both preamps and now own the Ayre. I would likely have bought the PS Audio if it had fixed-level outputs, which in my setup are necessary. Also, I found this comment about the Ayre to be a little odd: "If you've got three unbalanced sources, you're out of luck." No you're not, all you need is a $10 pair of adapters or, if you prefer, rca to xlr cables. A far easier-to-fix problem than the PS Audio not having fixed-level outputs.

rt66indierock's picture

I’ve said I wanted components volume matched in reviews and you provided it including your listening volume and the difference. Then you compare features and make a thoughtful comparison of the sonic differences. These items should be in every review.

Stereophile readers should note I’ve been extremely critical of what Jim has written about MQA.

dalethorn's picture

It's OK to be critical of a pro who knows what he's doing. Any well-thought-out critique is useful in comparing to those that aren't done so well.

Ryan Berry's picture

Hi Jim,

Thanks for taking the time to review the two units. It's not often that you see someone do a head to head, and I know how time-consuming and frustrating such ventures can be! A couple of things I'd like to mention related to the Ayre, hopefully this is the right place for it:

First, you mentioned the dB steps on the volume control...as you certainly know, the Shallco volume control we use in the KX-5 is very space-consuming and limits how many steps we have available. Because of that, we had to increase the step size more than we'd have preferred, but as Charley used to say, there's no such thing as a free lunch. The only alternative was to use a volume control that simply doesn't sound as good, which wasn't an option for a preamplifier at the KX-5's level. Where the volume control shines is in the lower ranges, as the KX-5 (and, of course, the KX-R) maintain its signal-to-noise ratio and clarity throughout the volume range instead of simply sounding better the louder you go. I like to think we made the right choice.

The XLR connectors actually don't click for a very different reason than you suspect: on every XLR connector, the lock clip is made of steel. Having a ferrous metal so close to your input has a negative impact on the sound. So we have technicians spend hours pulling the things out of every one of those connectors for that reason. It's the same reason we have every connector, capacitor, etc. custom made to avoid such materials in our products.

Last, on the remote, I think you still have the protective plastic covering the top of the remote. It's cut to exactly match the under layer, but peels off fairly easily. Some customers like to keep them on, so we didn't have a tab on it that would make it obvious that it's supposed to come off, so I can imagine there's a few people with it left on!

Overall, I appreciate your comments regarding the sound. What you describe reminds me of a slight warmth that you'd expect with tubes, whereas our focus has always been about recreating the clarity of the piece. Giving up the subtle noise that a violin's strings make as a bow is pulled across them is quickly lost when the sound starts getting skewed to sound warmer than the original, but I can certainly understand the draw to the sound.

Again, thank you for all you do!

Best Regards,

Ryan Berry -Ayre Acoustics

JimAustin's picture

Ryan, thanks for the thoughtful response. God I hope you're wrong about the remote still having the plastic cover over it, because if you're right, that's so embarrassing! Especially since I had two near-identical ones here including the one included with the Benchmark, which had the same issue. Both are gone now, so I can't check--although I expect to get the Benchmark (remote an DAC) back at some point.

As for "no free lunch", I totally understand, and I assumed as much. Although I never met Charlie in person--my loss--it was clear from our many online interactions (and much else that I read) that he was an uncompromising guy when it came to sound quality. Based on what I know, I'd expect him to make precisely that decision, and it's at least as valid as the alternative. (It's worth noting that the BHK's volume control is also pretty interesting.) As I see it, my job as a reviewer is, in part, to point out the trade-offs when they exist.

I think your characterization of the difference between the two preamps seems about right. We're talking about small differences, but the Ayre was a little more clear than the PS Audio and the PS Audio had that extra touch of no-doubt tube-induced ... something. Both are well-designed components that fulfill the vision of the designers and both are valid choices depending on what a particular system needs and a particular music-lover prefers.

Thanks for the time with the TWENTY.


Ayrehead's picture

Duh! It wasn’t until I read this message that I realized that what I took as early onset controller aging was in fact the plastic cover on the faceplate. I’m an aficionado of both Ayre (Preamp, Amp and Phono Preamp) and PS Audio (DAC & power control). Love you both!

Ortofan's picture

... how many XLR connectors, with the steel latch lever still in place, does the signal from a recording pass through before ultimately reaching the listener?

Ryan Berry's picture

Likely at least a few. That doesn't really excuse not caring about having a few more in the path, however. It's not a "once it's contaminated, it can't get any worse" sort of deal; it's more a matter of doing everything you can to avoid making the problem worse.

What's the overall effect of such clips? Pretty minimal, undoubtedly, but I don't believe people should be looking for simply adequate over doing things in the best way possible when we're talking about high end audio.

CG's picture

Know what would be cool?

Even if terribly impractical?

Actual measurements of components within the context of a complete system. In other words, does the KX-5 have better frequency response when used with an Acme SuperAmp 2000 than the BHK Signature does? How about when combined with an Acme MagnaDAC Mk17? How about signal to noise? Low frequency spectrum? And so on.

EricAnpin's picture

I had noticed this and wondered about it..but have not had any problems with cables falling out. :) Also, in my system, the 1.5db volume steps are perfectly OK, though others' mileage my obviously vary. As I mentioned above, the tape outputs are, for me, an absolute necessity, and quite a few manufacturers seem to be leaving these out. Another feature of the KX-5 which I really like is the ability to name inputs and set the gain level independently for each input - very useful. I would have liked a balance control; so far I have never needed it, but I can imagine situations wherein I might (tube on one side gets weak in phono preamp, etc.)

Ryan Berry's picture

Hi Eric,

Thanks for the very kind comments. It's true that we've never done a balance control. Mainly because we've never felt them particularly useful, but also with the way our mechanical volume controls work, it's just not practical unless we were to put in independent motors in with separate pulleys and belts...pretty expensive for a feature that we really don't think offers much purpose. I'll certainly bring it up again, but the R&D team always gives me funny looks when I talk about balance controls and equalization.

mapoulin's picture

Indeed, increments of 1.3dB are coarse enough that I had difficulty finding the appropriate volume for some recordings.

LOL, 1.3db having difficulty, what a set of golden ear you have...

Bogolu Haranath's picture

Gain levels would be nice in any preamp (tubes or transistor) in my opinion ........... That would be helpful for matching with many amps, tubes or transistors ....... Also some amps come with gain level settings, as well ...........

EricAnpin's picture


Thanks for the explanation - having looked at how you do the volume control... it's understood that balance would be tough to implement!!! Anyway fortunately it's not on my "gotta have" list.

Andrei's picture

Thanks for taking the time to give us your thoughts. It is very much appreciated. I hope other Stereophile writers will do the same when happenstance brings two similar products under one reviewer's roof.