General Information

Overview

Since the introduction of our flagship amplifier WA33, we challenge our engineers and design team to develop a compact version with an entirely new look that packs an unbelievably great sound to match.

Say goodbye to boring black boxes of Hi-Fi equipment. The all-new WA23 LUNA completely reimagines how audio components look and feel. From the curved lines around the volume controller that showcase the brass enclosure of the premium ALPS RK50 potentiometer to the strikingly beautiful black-and-gold chassis CNC machined from a single piece of aluminum. WA23 LUNA is uncompromising inside and out.

Each WA23 LUNA is expertly hand-assembled by master craftsmen with decades of experience in point-to-point wiring. The care and attention to detail requires patience and dedication to absolute quality. This small team is trusted to build our flagship amplifiers.

The foundation of WA23 LUNA is a single-ended triode pure Class A design, featuring a pair of 6C45 driver tubes, a pair of 2A3 power tubes, and a single 5U4G rectifier tube. The warm glow of the tubes draws you in from the moment you turn it on. Every internal part from the custom-made output transformers to Mundorf capacitors are carefully chosen through extensive listening tests for their sonic capabilities. When the music plays, the rich details, clean highs, wide dynamic range and deep full bass will immerse you in sound. A small external power supply allows WA23 LUNA to fit right on your desk or the side table next to your easy chair.

When innovation and unrestrained engineering comes together, performance is taken to new heights. WA23 LUNA redefines high-end audio.

Highlights

  • Introduced in February 2022
  • Single-ended, all-tube design (not hybrid), Class A operation
  • Power tube: 2A3 x 2, driver tube: 6C45 x 2, rectifier tube: 5U4G x 1
  • Self-biasing amplifier
  • Headphone amp or preamplifier
  • Transformer-coupled, Point-to-Point wiring
  • User selectable HI / LO impedance and HI / LO level for headphone
  • User selectable output: pre-amp or headphone
  • ALPS RK50 potentiometer in a brass enclosure
  • Mundorf Supreme Silver/Gold capacitor for interstage coupling, one per channel (4pcs)
    Mundorf MTube capacitors for voltage filter (3pcs)
  • Polytetrafluoroethylene (PTFE) tube sockets
  • Compatible headphones (8–600 Ohms)
  • Inputs: XLR x 1, RCA x 2
  • Outputs: preamplifier (Pre-out) XLR x 1, headphone outputs: 4-pin XLR and 6.3mm (1/4”).
  • Frequency response: 10Hz to 50KHz
  • Preamplifier voltage gain:
  • CNC machined aluminum chassis milled out of a solid block of aluminum in an anodized, sand-blasting finish
  • Color: black and gold
  • Operating AC voltage: 115v – 230v (voltage below 115v requires step up transformer)
  • Dimensions:
    • AMP without tubes: 16” L x 10-5/8” W x 4” H (407mm x 270mm x 102mm)
    • AMP with tubes installed 16” L x 10-5/8” W x 7” H (407mm x 270mm x 178mm)
    • PSU: 7” L x 4-1/8” W x 3-1/4” H (178mm x 105mm x 83mm)
    • 1.0m (3.5ft.) custom-made premium umbilical cord [custom length available]
  • Weight: 30 lbs / 13.6 KG
  • Power consumption: 150 watts
  • Designed and assembled in New York, USA

Latest reviews

Aetherhole

100+ Head-Fier
WA23 Luna - A Statement Piece
Pros: +Aesthetics
+Unit build quality
+Macro dynamics
+Large sound stage
+Timbral/Tonal quality
+Micro dynamics
+Resolution
+Customizability with tubes
Cons: -Higher Cost
-This amp and tubes gets hot
-Won’t be usable with IEMs or possibly even very sensitive headphones due to inherent noise
-Single-ended amp design
Statement Piece - A stunning statement piece can create drama or be a focal point. The point of it is to capture interest and stand out in your space.

The Woo Audio WA23 Luna is a statement piece, through and through. It draws attention. Its design elements stir up discussion. One can’t help but see the WA23 and immediately give pause. Its looks are unique; moreover, one of the most fascinating design elements is its duality. The color scheme of a solid black chassis and gold accent trim is exuberant yet refined. It’s both subtle and bold. It’s anything but a subtle piece of audio gear, but its design practically screams stealth. It’s so grandiose without being gaudy. It’s classy looking. It is one of the most tastefully designed pieces of gear ever to hit the market. For a piece of audio equipment, that’s well and good, but if it doesn’t function or perform well, then it’s all for naught. Thankfully, the WA23 doesn’t just create a stir with its aesthetics, it has the functional performance to back up its artistic design.

Typically, I lean heavily towards solid state amplifiers. I want dynamic range. I want punch. I want detail. All those things are easily found in solid state amplifiers without hardly any sacrifices. Moreover, all those things can be found without breaking the bank. Solid states that can drive difficult-to-drive transducers are in abundance and at affordable price points. The headphone amplifier world in previous years has been akin to questions like, “can it drive the Susvara?” In more recent years, it’s been refined to, “how well will it drive the Susvara?” Finding a solid state to be able to achieve that was a rarity, a crowning achievement, even. Forget about getting a tube amplifier that could drive such difficult headphones, back a few years ago. Nowadays, solid states that can drive the illustrious Susvara, among other difficult headphones, are a plenty. Tube amplifiers have made monstrous headway, and we now have some top-tier ones, like the Feliks Audio Envy, Cayin HA-300B mk2, Woo Audio WA33 SE and the EE, to name a few. And now also the WA23.

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The WA23 Luna is certainly enough to drive the Susvara and to volumes louder than I am comfortable listening to, and it can do so beautifully, to boot. However, an important note: this will depend on how much signal voltage you are sending to the WA23. Gain staging is important here and if you’re DAC is feeding a standard 2v signal, it probably will not be enough to drive Susvara to a sufficient volume, or other hard-to-drive headphones. The Holo Audio May does just fine with the 5.8v XLR output. I have the WA23 set to low gain with the volume dial set between 12-2 o’clock, depending on the tracks. For extended listening periods, this is where I am most comfortable. I can push it to about 3 o’clock, but for longer sessions this is too much. For more leisurely listening, I might nudge it closer to 11 o’clock on the volume knob.

I’ve heard a lot of amplifiers in various capacities, but the headphone amplifier I’ve had the most extensive time with is the Ferrum Oor prior, so most impressions or thought comparisons are based off that.

I have tested pre-amping chains with the Oor and the WA23. Using the Oor as a pre-amp to the WA23, I did not particularly like what the Oor did to the sound. You really don’t gain much from this set up. With the WA23 as a pre-amp certainly adds some of the coloration and characteristics to the Oor, but ultimately, I did not find that the WA23 & Oor combination was a good fit. Most of my reasoning with this is because the WA23 outperforms the Oor in just about every aspect, which I’ll explain more in my impressions of the WA23. I could possibly see very specific use cases where it could be useful, but all in all, having the Oor in the chain did not improve the listening experience at all. The WA23 is just a better amplifier all together. I certainly will be playing with the WA23 as a pre-amp more when it’s finally my turn to have the Zähl HM1 in house, but a while off now.

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So, how does the WA23 sound then? These words come immediately to mind— Beautiful, lush, authoritative, engaging, and effortless. Buckle up though, I’ve got a lot more to say.

When I first began listening, the first thought I had was, “wow, that is quite powerful.” My initial concern that the WA23 wouldn’t be sufficient enough for the Susvara was put to rest in the first 10 seconds of my first listening track. The first test track I used was Daft Punk’s “Give Life Back to Music.” The opening sequence of this song gives a good sense of how much impact it can have. As the song continued, the complexity of the jam-packed layering, really show the resolving capabilities of the amp. That was a fun introductory experience for this amp. I had every intention of switching tracks after the first track finished, but as the next song began to play, I remembered there were things that I wanted to hear there. Track after track played and before I knew it, I ended up listening to the entire Random Access Memories album. One of my favorite tracks on this album, however, is, “Giorgio by Moroder.” Starting at the 6:23 mark, there’s intricate details stacked in drums, synth, guitars, melodic line, and vinyl scratching. Attacks and decays of the various sound elements during this portion are a whole lot of fun. No matter how busy this sequence got, the sound was clean and effortless. The layering remained deep while well defined. The WA23 resolved all the details succinctly and, surprisingly, with more texture and body than I was used to. At the 7:45 mark there is a series of drum hits are blazingly fast, which can appear a bit muddied by all the added track layering, but the prominence here of the drum passage with accompanying thumps and cymbal splashes were never lost, once again, really displaying the effortlessness of the WA23. I will quickly add another favorite track of mine from the same album, “Motherboard.” Various instruments, like strings, flutes, and acoustic guitars, are interspersed with synth and drums that give so much body and life to the song that similarly impressed me.

Shifting gears away from Daft Punk, another track I listened to is Tool’s “Chocolate Chip Trip” from the Fear Inoculum album. This track, while less melodic than the tracks mentioned above, has several elements that flexes this amp’s strengths. At the beginning of this track there are wind chimes that are played in a bit of random sequences. They seem to hit and linger, ringing in a manner that exudes realism. I believe this perceived realism is due to the 2nd order harmonics from the tubes. The tiny bit of overtone series the tubes add, sweeten the sound of these chimes in a way I’ve not heard on any solid-state amp I’ve tried. Additionally, the various chimes come from different directions and distances in the sound stages. Another aspect of this song I really enjoy is the focus on Danny Carey and his drum kit. The splashes, slaps, hits, and kicks are distinctly tactile. There’s industrial sounds and synth that float back and forth through the left and right channels. The bouncing back and forth is persistent throughout, but amongst all the busy passages, it can get lost. Especially with the kick drums and crash cymbals, the panning and succinctness can often get lost. Not so on the WA23.

A track I’ve recently discovered that has made it into my regular testing/listening rotation is “Antecedent” by The Omnific. This progressive rock band is comprised of two bass guitarists and a drummer, a bass-head’s delight, for sure. There’s depth and heft inherent, but there’s also a ton of speed to the sound, as well. Also, the bass guitars have some effects pedals that are just really cool sounding. The note separation, especially in the lower registers, often blend together on lesser capable electronics or transducers. The combination of the rich timbre and transient agility of the WA23 pair marvelously with this track. The space between notes and drum attacks is palpable. Each strum and pluck of the metal bass guitar strings are almost felt as much as they are heard. No matter how quick, each onset is tangibly audible, and reverberate as such. The rest of the album, Escapades, is just as engaging and if “Antecedent” is right up your alley, listen to the rest of the album, too.

I’ve described a couple of parts of the sound reproduction of this amp already, gushing about the details and transient response, but one reoccurring standout aspect you might have picked up on certainly has to be the tonality, texture, and tactility of drums. The topic of tonality and tactility being at the forefront, lead to one of the most important aspects of my music enjoyment that I want to talk about next — Vocals.

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I’m a classically trained vocalist. I sing semi-professionally in various forms, including mens chamber groups, large chorales, and church choirs, quartets, and solos. I say this only to illustrate that vocal representation is something I pay a lot of attention to. Classical, opera, choral, a capella music are types of music I thoroughly enjoy. Not limited to just those, though, vocals intrigue me in every genre, but I do have a soft spot for live music and live-recorded music. A go-to track that I use often comes from a vocal group called Voces8. From their album Eventide, the track,” The Seal Lullaby,” composed by Eric Whitacre, has the eight singers spread distinctly around the listener. Each of the singers' positions in the sound space are discernible, with each of the vocal parts coming from very specific directions. Each of their vocal timbres are well represented on the WA23. The harmonies and overtones that linger in the hall reverberate sublimely. The octet is also accompanied by a harp, which sounds heavenly and so, so sweet. It’s a beautiful song made even more beautiful by this amp. Other tracks on this album also have other instruments, like a saxophone in the track, “Quanta Qualia” that sounds elegantly smooth.

Keeping with the acapella theme, a mens chamber group that I love listening to is Chanticleer. Their rendition of Franz Biebl’s “Ave Maria” from their A Chanticleer Christmas album is one of my absolute favorites, partially because I’ve heard the group perform it live and because I’ve performed this song many times myself in the mens ensemble I sing with. It features four part mens harmony and also a separate mens trio, so seven separate parts. At the beginning of the song, the main group sings the chant in unison on the left half of the stage, but as they finish, on the right, you can hear a couple of quiet footsteps from dress shoes as the trio steps into place. These footsteps are pinpoint accurate where you can hear them on the right side at about the 2 o’clock position, but the reverberation of the steps of the hall just echoes as the trio begins to sing. It is quite marvelous. Each individual vocal part is noticeable as it is sung, but then just float away into the cavernous hall they recorded in. I’ve listened to this track probably a thousand times and the realism I get when listening on the WA23 is as close to the live performance experience as I’ve ever gotten, emotion and all.

I also must make mention of Geoff Castellucci’s cover of “Sound of Silence.” This bass vocalist has rich, deep vocals and a timbre that I really is impressive by itself. He layers his own harmonies with his own voice, so the timbre match is especially pleasing. However, notably, the sub-bass presence in this track is quite extreme. The depths will properly pressurize your headspace, testing the limits of the amplifier and transducer. The WA23 effectively took this track and said, “here, hold my beer…” keeping up with the demands and added texture and proper nuanced details across the board. However, just as impressive is the more intimate moments where I could more tangibly hear the press and lift of his hands on the piano keys at the beginning. Geoff’s plosive consonants, “t” and “s” and the softer “d” and “b” sounds also each had a touch more air and texture.

I will also quickly mention, I really enjoy listening to Billie Eilish on the WA23. Her intimate vocals really are markedly more engaging on this amp. And the macro dynamics of this amplifier really lend itself to this. I really like the track, “bury a friend.” Intimate vocals, authoritative bass, deep sub-bass, and plenty of opportunity for each element of the track to get lost in congestion, but the WA23 handles it aplomb.

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What about Classical? One of my favorite albums lately has been “Tchaikovsky & Schulhoff: Orchestral Works” performed by the Pittsburg Symphony Orchestra & Manfred Honeck. Violins, violas, cellos, and double basses have real sonority. Yes, the strings sound wonderful, but the brass and horns really take the cake for me on this one. Trumpets can typically sound blaring to me, but with the WA23, there is trumpet prominence with no biting forwardness. The brass instruments all sound rich and pleasing, as do the woodwinds. The timpani and drums once again also have a good sense of tone, impact, and bounce to them. It is a really, really good listen.

While there are great instances to show off the treble response in the tracks that I have outlined already, one track that I want to mention specifically that brought a smile to my face was Janet Jackson’s “Together Again,“ from her album The Velvet Rope. The beginning 50 seconds feature a heavenly harp that glissandos a few times, panning across the sound stage. There are also some distant chimes that sound ethereal and angelic. Janet begins singing and the whole sequence just has this beautifully airy quality to it.

I have also listened to a good amount of hard rock and metal from various bands, like Metallica, Dream Theater, Korn, System of a Down, Avenged Sevenfold (their track “Nobody” was a real enjoyment on this amp), which can be intense and have a lot of bite and grit. For longer listening periods that normally would be fatiguing, I did not experience that with the WA23, in fact, I found myself more engaged as I was listening. A few things contribute to that— one: the drum kits, specifically the crash and hi-hats can be a bit much for extended periods of times but aren’t as edgy here. Two: guitars, both acoustic and electric, really have a more musical quality on this amp. Three: Drums have more tactility and punch on this amp and just simply sound better.

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I truly cannot decide what aspect of the WA23‘s sound signature that I like more, it is all just so good. I have listened to hundreds of tracks and on countless albums, sometimes multiple times. Many times coming to the end of a track or album, and I think I’ve nailed down a favorite aspect, then I move onto another set of tracks or a different genre, I change my mind. I’ve written examples of elements of how it sounds and if you couldn’t tell, I am utterly enamored by it. Bass digs deep, its impactful, its textured, its full-bodied and lacking bloated, its realistic. Midrange range is rich, lush, and engaging, without being too thick and soupy. Treble is sparkly, immensely detailed, and free of harshness, all while retaining a very sweet quality to it. Let me be clear, though, I use words like lush and rich, but this amp is not dark. It does not sound muffled, rounded, or closed in at all. Transient response is superbly fast. Sound stage ranges from massive, when the song calls for it, to intimate when it needs to be. Holography is supreme with a remarkable level of depth and precision in layering within the sound stage.

I have a difficult time finding fault in the WA23 Luna. It’s not a perfect amplifier, as I mentioned earlier, but it doesn’t really do anything wrong outright. Other amplifiers outclass it in individual sound elements, but it’s not going to be huge margins there. The WA23 is just so well-rounded. I’m reaching when finding anything remotely negative to say about it. If I say, it runs hot or that it’s quite heavy, does that count? Well it does and it is, but that ought to be expected. Oh, I could mention as a negative, this could not be used with any of my IEMs. My 64Audio A12t and Thieaudio Monarch Mk III both had a pretty noisy, buzzing background plugged into it. I suppose, the aesthetics, while incredibly unique, will not be for everyone, either. There is no faraday cage to protect the tubes, if you are worried about that. Also, yes, this could be a deal-breaker to some, but the WA23 is a single-ended design and that may not appeal to everyone, though even with that, for convenience, there are XLR inputs and outputs that can be used.

There aren’t many pieces of equipment that have me giddy in anticipation to use, but the WA23 has me eager to press the understated golden power toggle. I simply get lost in the music with this amp; hours will go by while I listen. It’s been over six weeks since the WA23 arrived and not a day has gone by, whilst home, that I’ve not listened to this amp. It’s superbly nuanced yet grandiose in its dynamism, harkening back to what I stated at the beginning regarding the duality of this amp. I also stated that I lean heavily towards solid states, but the WA23 has me questioning all of that. Even with stock tubes, this thing is remarkable. Others might prefer a more clinical or neutral sounding amp, even within the tube realm, the Feliks Envy or Woo WA33 will likely fit the bill for those folks. Others might prefer an amp that will lean even more lush and romantic. Yes, there are other amps I’ve heard that have better individual characteristics, being more detailed or resolving, having a larger soundstage, having more lush, rich quality, or having better macro dynamics, but this amp stays right up there among the very best of each of them, all whilst staying uniquely well-rounded. It does it all, while being more musically engaging.

The Woo Audio WA23 Luna is a statement piece. And it is a work of art.

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Aetherhole
Aetherhole
@Echo42987 if/when you come to So Cal for Can Jam, you know you’re more than welcome to come on over to listen!
smodtactical
smodtactical
Have you compared to any other tube amps ?
Leto Dal
Leto Dal
Interesting, there is zero noise with Feliks Envy even with IEMs. Thanks for the review.

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