ULTRA AUDIO -- Archived Article

July 15, 2007

Ayre Acoustics K-5xe Preamplifier

The little brother gets no respect.

It takes only a cursory search of the Internet to unearth mountains of information about Ayre Acoustics products, from their statement-level V-1xe power amplifier to their K1-xe preamplifier and the ubiquitous CX-7e, which just about everyone who’s anyone uses as a reference CD player.

But dig a little deeper into the Ayre line and there sits little brother, the K-5xe preamplifier, lonely and essentially unreviewed by the same audiophile press that can’t seem to get enough of Ayre’s top-level products. I’ve had my eye on the K-5xe for some time now, as the P-5xe phono stage has held pride of position in my system since I reviewed it in 2005 -- and after all, they’ve got the same number.

The P-5xe phono stage is one of those rare audio components that sits there, elegant as all get-out, never intrudes on the music -- and thus stays out of perception -- and quietly performs its job in an efficient, invisible manner. Doesn’t that sound exactly like what a good preamplifier should do? Well, that’s why I bought it, and it’s why my mind kept coming back to the K-5xe. At $2950 USD, the K-5xe seems as if it would be the perfect companion to the P-5xe.

The suspense was too much to bear. I contacted Steve Silberman of Ayre Acoustics, and he agreed to send me a K-5xe, along with a companion V-5xe power amplifier, so that I could investigate the familial synergy of a complete Ayre system.


The Ayre components impressed even before I took them out of their boxes. Amplifier and preamplifier ship in sturdy cardboard boxes, but instead of Styrofoam, Ayre uses cardboard spacers for the V-5xe amplifier, and a super-nifty suspension system based on cardboard and some sort of clear, springy plastic for the K-5xe. Thanks for doing your part for the environment, Ayre.

Once I’d decanted the K-5xe, the good impressions continued. Consisting of a solid, inert, rectangular box measuring 17.25"W x 4.75"H x 13.75"D, the K-5xe felt heavier than its 25 pounds would suggest. Its brushed, anodized aluminum panels are well damped -- a rap on the top plate elicited a dull thud instead of the alarming tang that emanates from the rattly steel chassis of lesser (but not necessarily less expensive) gear. A closer examination revealed high standards of construction and close tolerances, with little or no gaps between chassis parts.

The front panel is clean and uncluttered, with a central window that displays the volume in blue numerals in increments of 1dB. The input switches are arrayed below the display, labeled with quirky but intriguing symbols -- star, planet, moon, comet -- which you can categorize using the mnemonic device of your choice. There’s also a buffered tape loop and, on the far right, a mute switch. The volume knob is silky and freewheeling, connected optically via FETs to the K-5xe’s array of metal-film resistors. Although I didn’t open the K-5xe’s case, Ayre claims that its power supply, especially the transformer, is exceptionally chunky -- as indeed it must be to jack up the weight of this relatively small box to 25 pounds.

If you’ve paid even passing attention to the audiophile scene, you know that Ayre Acoustics made its name on two principles: zero feedback and fully balanced operation. Steve Silberman explained, while setting up the K-5xe and V-5xe, that Ayre feels that while the use of feedback can provide better measurements, the zero-feedback circuits used in Ayre products are more musical by far.

Balanced connections are more complicated to implement than are single-ended, requiring almost double the number of circuits and the parts required to build them, which of course raises the cost of manufacturing. In return, the technology’s proponents say, balanced connections reject noise and permit longer cable runs. The K-5xe features two balanced inputs, one balanced output, and an equal number of single-ended connections, along with the tape loop. Any one of the K-5xe’s inputs, single-ended or balanced, can be configured as a processor pass-through input for use with a surround-sound system.


Hooking up the K-5xe was simplicity itself. There is no power switch -- the K-5xe powers up as soon as it’s plugged in. For the first time, I was able to use my Benchmark DAC1’s balanced outputs (my Sonic Frontiers SFL-2 has only one balanced input, which I dedicate to my phono stage), connected to one of the K-5xe’s balanced inputs (my P-5xe phono stage took the other one).

The K-5xe fed its signal to either the Ayre V-5xe or my own Anthem Statement P2 amplifier, and I spent a good bit of time switching amps to get a handle on what each piece of Ayre gear was bringing to the party. I used only balanced connections between amps and preamp.

Sources consisted of the Pro-Ject RPM 10 turntable (now a permanent resident of the Thorpe household) with my beloved Roksan Shiraz cartridge bolted to its pointy end. My Toshiba SD-3750 DVD player has been replaced by an Oppo DV-970HD, at the insistence of Roger Kanno of www.hometheatersound.com. Speakers were Focus Audio’s Master 3 throughout the entire review period, connected by Acoustic Zen Satori cables. Interconnects were all Analysis Plus Solo Crystal Oval (balanced), although I also used the stock interconnect provided with the Pro-Ject RPM 10. Power cords were Shunyata Taipans for the most part, not including the occasional dalliance with Cardas Hexlink 5s. All AC cords were plugged into a Shunyata Hydra Model-6 power conditioner, though I did experiment with Ayre’s recommendation of connecting their products directly to the power source.


Completely disregarding Ayre’s recommendation of 100-500 hours of break-in, I gave the K-5xe and its squat little buddy, the V-5xe, a full 30 seconds to warm up, then sat down for a listen. I never did confirm if Ayre had broken-in these two units at the factory for me, but they may well have -- I noticed little, if any, change in their sound from the first note to the last, just before I boxed them up to ship back to Ayre.

What I did notice -- instantly -- was a dramatically low system noise floor. Without music playing, and the turntable’s cuing arm raised, the Ayre system was dead silent, almost to the point of sucking the ambient noise floor right out of the room. With the furnace off and no one else in the house, the system and the room itself were silent. Of course, almost all solid-state gear these days is quiet, but the K-5xe took things to another level. Even with my ear right up to the speaker, I couldn’t tell if the system was powered up or down. So I lowered the tonearm onto one of the best-pressed LPs I own: the third of Peter Gabriel’s eponymously titled solo albums, aka Melt and/or Three, this one from 1980 [Atlantic/Classic PG3].

I’ve heard much made of the similarity of Ayre equipment to tube gear, but my initial reaction to the K-5xe didn’t lean in that direction. To my ears, tubes add a subtle sparkle to music; the best tube equipment carefully leverages that characteristic toward a better sense of space and dimensionality of harmonic overtones. The K-5xe didn’t add anything. In place of the additive enrichment and high-calorie lushness of tubes, the K-5xe carefully extracted the music and passed it on with almost nothing added or subtracted.

Ayre Acoustics V-5xe Power Amplifier

Some say synergy is everything. At the very least, it shouldn’t be overlooked, I say. In this context, synergy was the result of spending two months listening to a complete Ayre system comprising a P-5xe phono preamp, K-5xe preamplifier, and V-5xe power amp.

The V-5xe ($4500) is claimed to be a member of the Double-Down Club: it doubles its power as the speaker’s impedance halves. In this case, that means it puts out 150Wpc into 8 ohms or 300Wpc into 4 ohms. While the benefits of this are dubious in the real world, it does mean that the V-5xe packs one hefty power supply. Sure enough, it’s a chunky little guy: 18"W x 7"H x 16"D and weighing a dense 55 pounds. Like the -5xe preamp and phono stage, it’s a beautifully finished, inert block.

With one Power/Standby button up front, the real fun lurks ’round back, where Ayre has provided some seriously robust binding posts operated by a single large thumbscrew. I thoroughly enjoyed this innovative design. I’m not quite so enamored of the up-and-down mirror-imaging of the connectors -- I would much prefer that everything lined up nicely on a horizontal plane. Call me old-fashioned.

For the duration of the review period, the V-5xe performed flawlessly. It ran just warm to the touch, which is fine as far as I’m concerned. Never trust an amp that runs cold, my dear departed pappy used to say.

All three Ayre products share a distinctive house sound that leans toward the crisp, clear, see-right-through-the-soundstage end of things. In comparison to the K-5xe and P-5xe, the V-5xe seemed to inject just the tiniest bit of warmth into the all-Ayre system, slightly fleshing out the midrange and the area just above it, adding a little more body to vocals and some extra wood to stringed instruments.

Consider that additional juice through the midrange in the context of how the other Ayre products, especially the K-5xe preamp, convey the music’s harmonic intricacies. The V-5xe amplifier had no overt richness, yet the images from the midrange right through the treble contained ample detail and delicate subtlety. It’s all about insight into the music, and the V-5xe delivered it in spades.

For decades now I’ve enjoyed pianist John O’Conor’s interpretations of Beethoven. They could be considered a touch delicate, but that’s why his playing is that much more passionate when he lets loose in Presto of the "Moonlight" Sonata, from Beethoven’s Piano Sonatas Vol.I [CD, Telarc CD-80118]. O’Conor’s piano has scale and majesty here, and the V-5xe dug deep to present an outstandingly solid image. Each hammering note of the crescendos in this movement was imbued with O’Conor’s innate pensiveness, and the V-5xe’s natural delicacy provided me with additional insight, almost showing me the movements of his fingers.

Like the K-5xe preamp, the V-5xe presented ample treble extension, sounding slightly forward but without the slightest hint of grain. There was admirable sparkle in the V-5xe’s top end, and with its exceptional purity in the highs, it was possible to listen for extended periods without fatigue. In comparison to my Anthem Statement P2, the V-5xe’s highs were slightly more elevated in level but also slightly cleaner -- an admirable tradeoff, in my book.

Down low, the V-5xe had good grunt but was no miracle worker. The bass was deep, tight, and tuneful, but slightly down in level. In the context of the slightly forward highs, this made the amp sound very slightly lean. However, its slightly warm midrange ameliorated this tendency, and the end result was a thoroughly enjoyable sound.

The Ayre V-5xe is about twice the price of my Anthem P2, and delivers half the power -- on the face of it, an eyebrow-raising equation. But the V-5xe has enough tricks up its sleeve to warrant its higher price. It’s stunningly built, and boasted an incredible purity of sound that was apparent right from the first listen. The V-5xe merits a solid recommendation from this listener.

…Jason Thorpe

But the K-5xe did something special that went a bit beyond adding or subtracting information. Gabriel’s "No Self-Control" is a dense, claustrophobic song that vivisects the small, dirty cubbyholes of a disturbed mind, and it takes several listens to dig down beneath the obvious into the almost Jungian emotions with which it’s charged. From the first notes, the K-5xe presented a clear, easily deciphered view that let me better investigate the dense interplay of the instruments. This entire album is clustered around the midrange, and any congestion in this range removes much of the music’s immediacy. I heard no such congestion -- quite the contrary. The K-5xe delineated every stroke of Phil Collins’ drumwork, each razor-sharp note of Robert Fripp’s guitar, with almost hallucinogenic immediacy. By increasing the apparent space between the instruments and by carefully disentangling the closely clustered borders of the acoustic space, the K-5xe helped me get even closer to this deeply disturbing song.

I’m always on the alert when a component at first seems to reveal more detail in music, because such traits are often accompanied by thinness and etch. I generally don’t worry about it, however -- if it’s doing this, I’ll find out in the long run. Fortunately, the K-5xe didn’t walk this path. While there was no way I could have mistaken the K-5xe’s eminently neutral tonal balance for a lush, chocolatey tube preamp, the Ayre didn’t bleach the richness out of music. Deeper into Gabriel’s Three, the totally out-of-place but still exciting "And Through the Wire" has an abrasive tonal balance that the K-5xe portrayed with all of its sharp edges intact, but without exacerbating the condition. Gabriel’s voice was appropriately aggressive, and the overly echoed chorus displayed good depth and density, the dynamic swings of the chunka-chunka drum work coming through with an admirable intensity.

Impenetrable, busy music makes for fun listening but difficult reviewing. I found it much easier to get a handle on the K-5xe’s character by listening to The Tony Bennett/Bill Evans Album [Riverside OJC-439]. Bennett’s voice, from my punky little Original Jazz Classic pressing, has a delicious, subtle halo that my Sonic Frontiers SFL-2 tube preamp tends to accentuate with additional harmonic overtones. The Ayre K-5xe didn’t resort to such trickery. Instead, it seemed to dig deeper into the actual acoustic, standing clear of the action while revealing the harmonics on which the real musical action depends. I guess it’d be simpler just to say that the K-5xe was clear through the midrange, but that would be doing it a disservice. While it definitely sounded open, clear, and unrestrained through this range, it did seem to go out of its way to help reveal the music’s character -- its soul, if you will.

Los Lobos’ La Pistola y El Corazón [Slash 92 5701] is a busy little gem of a record -- beautifully recorded traditional Mexican music stunningly played on mostly acoustic instruments, and a microcosm of all that’s important to both music lovers and audiophiles. While La Pistola is quite fast-paced, there are a couple of delightfully melodic tracks that confidently deliver tasty slices of rural Mexico. I’ve found that the frantic violin on "Las Amarillas" can have a metallic edge through any component that leans toward thinness. The K-5xe refrained from hardening any of the string textures with which this track is littered, while keeping distinct all of the densely packed instruments and voices.

Being a tube lover of long standing, I always lean toward the Dionysian side of the audio equation -- I far prefer warm and lush to crisp and dry. As I’ve said, the K-5xe didn’t sound tubey, but it did manifest some of the same spatial and emotional qualities of my tube-stuffed SFL-2. I know that a component is going above and beyond the call of duty when the music makes me pause in my tracks, look up at the stereo, and crack a big, wide grin. I repeatedly experienced this phenomenon with the K-5xe in the system, and the most recent example was when I gave La Pistola another listen. "Estoy Sentado Aquí" is music to drink tequila to while you lament the lost love of your life. The accordions, guitars, and big-assed acoustic bass in this track all combine into a luscious musical stew. The K-5xe had a bottom end that managed to be solid-state-tight and harmonically complete at the same time, and this juicy foundation, along with the Ayre’s knack for instrumental placement, made for that look-up-smile-and-chuckle moment.

Finally . . .

My overall reactions to the Ayre K-5xe flowed from one extreme to another. At times I wanted a bit more lushness, at others I was astounded at how the Ayre managed to draw me into the music. It’s fairly easy to dismiss my desire for a richer sonic palette -- I came to the K-5xe directly from reviewing a tube preamp. It’s far more telling to consider that the solid-state Ayre was so easily able to involve me in the music to the extent that it did.

As I packed up the Ayre preamp and power amp for return to the factory, I asked myself what sort of person would be the potential customer for the K-5xe. I suspect it won’t tempt the committed tube lover to decamp for the land of silicon. While the K-5xe is a delightfully neutral preamplifier, and while it did full justice to the intent and soul of the music I played through it, it was definitely not lush in the tubular sense -- and that may be a deal-killer for those looking for a cool-running alternative to tubes. On the other hand, those used to solid-state preamps will undoubtedly welcome the Ayre’s deft way with harmonics and its exceptional portrayal of space, and end up completely enchanted.

After my splendid experience with the matching P-5xe phono stage, I had high hopes and high expectations for the Ayre K-5xe, especially at its altogether reasonable price of $2950. Now, having listened to and lived with the K-5xe, it’s easy to see why so few units show up on the used market. With its dead-quiet, unfussy operation, superb build quality, and totally neutral tonal balance, its level of performance is usually the domain of preamplifiers costing twice as much.

…Jason Thorpe

Ayre Acoustics K-5xe Preamplifier
Price: $2950 USD.
Warranty: Five years parts and labor.

Ayre Acoustics, Inc.
2300-B Central Ave.
Boulder, CO 80301
Phone: (303) 442-7300
Fax: (303) 442-7301

E-mail: info@ayre.com
Website: www.ayre.com

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