Enleum Amp-23R stereo amplifier by David Abramson
One of those (exalted) boxes…
The Enleum Amp-23R is one of those boxes that come along every now and again, tumbling in headlong upon a wave of 5-star reviews and heady praise from seemingly all bass-trapped corners of audiophilia. Yup, from The Audiophiliac (patented) to Head-Fiers to the Steve Huff-meister himself, seems anyone who’s everyone (and their family members and sometimes the dog) has praised this tiny black (ok, it’s a bit grayish?) brick. Many have refused to return said brick after review, vowing instead to die atop this particular tiny brick hill, lest they be denied it takes pride of place in their reference systems for all eternity and infinity (or at least until the amp-24 Mk. II SE comes out).
Of course, minor players like myself wanted in! ‘So let us collectively see what all the chorus and Kyrie is about here.’ Such were my thoughts when I (electronically) hit up the (exceedingly) gracious head-of-Enleum Soo In Chae for a review sample. It seems heady praise has not gone to Soo In’s head whatsoever, as he quickly responded to my queries himself and graciously obliged, firing one my way tout suite.
The (grayish?) black brick
Let’s just say I don’t think shipping costs are high. The 23R is small; spelled with an S. M. All. And it’s dense. It’s very well packed amidst that lovely soft-but-not-too-soft foam some fancier companies use, and upon retrieving it, you find it really is as they say; a super solid, artfully machined black(ish) brick, minimalist to the core with two buttons (power/input switching and mute), a (vaunted) headphone output (which I never evaluated because this isn’t Head-Fi) and a volume knob with large knurls machined in.
Soo In tells me that the volume knob, by the way, is apparently (digitally) capable of something like 1024 steps but is factory limited to about 40 times fewer steps as it is not strictly a potentiometer attenuating the amplifier’s fixed gain, but rather an extension of the amp’s ‘Ensence’ PCB module whose circuitry employs discrete transistors and, is a somewhat unique way of doing things in that it dictates the setting of playback volume by direct adjustment of the amplifier’s gain rather than by attenuation of a fixed maximum gain. As there has been the spilling of much cyber ink about this attribute by learned electrically-knowledgable ‘philes, as an un-learned non-engineering ‘phile, I will simply add that per its designer, this arrangement yields significant benefits in terms of sonic purity and is a more direct, generally less wasteful way of doing things. Additionally, Soo In’s ‘adequately’ powered (at 25 watts a side) artfully machined brick utilizes a zero negative feedback design and has a (relatively) low damping factor, which some speakers will take to like ducks to a (very often man-made) lake.
I asked Soo In if the above 1024-step capability means I can have more volume steps or fewer or different-sized jumps in between them, and he replied, “Yes, it’s theoretically possible to increase it up to 1,024 steps, but we considered it’s too much and there’s also a possibility of software error caused by external changes in temperature and voltage, so we fixed it as is now. Actually we have not received any complaints about it [author: heh heh. Yet!!] and I think we better stick to it rather than customizing for everyone’s different needs.” If you’re a Kardashian, maybe you can get what you want, but otherwise, there you have it. I mentioned, by the way, that I’d be comparing the Enleum against an artisan tube amp or two, and he seemed unafraid, telling me, “I know that some people use nice tube preamps, but it has to be very very good not to sacrifice the AMP-23R’s micro detail levels. For example, I have a Nagra Jazz in my personal collection that’s now covered in dust. I actually left tube equipment a while ago, but sometimes enjoy it with their different sound characteristics.” Ok, so the man is not into tubes, but when he was, he had good taste!
Ze painting is a single white square. Zat will be 20 million euros, yes?
Think the Enleum’s two inputs is ‘minimalist?’ My Lejonklou Boazu integrated takes minimalism to 11 by having NO input switching. Every input is active all the time! H.A.! Take that! But it also doesn’t have a much-lauded headphone jack like the 23R or a volume knob. It’s a ‘buttons only amp’; volume up, volume down, and mute. Yep, all I do is stream Quobuz and Tidal these days, and I use a single digital source; the slightly warm but very convincing Holo Audio KTE May DAC (until, of course, the KTE May Mk. II SE comes out), so all I need is volume and an input or two, and I’m good to go. Fair to say those of you running your entire Hamptons guest house home theater system off a single amp need not apply. Stick with Sonos!
I loved the super cute little vibration-dampening screw-in footers provided with the Enleum as standard now (they used to be an optional extra), and they screwed in easily and made the amplifier rock stable upon my console. Ok, it slipped around a bit when I plugged and unplugged cables, but Soo In has even thought of this! The amp comes standard with a tiny packet of thin white rubber circles, one of which fits perfectly under each dampening foot! The amp was then incapable of sliding around at all, despite my best efforts. This man has thought of everything!
Hitting the brick(s)
First, I needed to find the right wires. [Trigger warning: Cable deniers, a brief discussion regarding (considerable) sonic differences in cables will occur. Please look away now!] The Enleum showed itself immediately to be one of the few amps that didn’t seem to play nice in my system with my Lejonklou Boazu’s fave Linn K20 speaker cable. The sound seemed edgier and brighter, and all things I’d read about this amp told me that shouldn’t be the case.
Luckily, I found two speaker wires I had here that worked beautifully with the 23R and one was my ‘normal people cable’ fave, the Skywire 1400 SE speaker cable, and the other is the somewhat further afield Jeff Day find, the Dueland Audio DGA 16 gauge tinned copper speaker cable. With either cable, the 23R became at ease and balanced, with no part of the frequency band, highlighted or suppressed.
The cable squared away; I immediately noted this gray-black brick could play! Early in my review period, I digitally ‘spun’ one of my recent fave piano albums, Ahmad Jamal’s ‘Marseilles,’ and Jamal’s piano was dynamic and impactful, large scale and sonorous. This album demonstrated well what would be one of the hallmarks for me of this brick; sonic scale. Maybe Soo In focused on scale somehow in ‘voicing’ this guy in order to ensure it didn’t sound as small as it looked!? The Enleum is indeed impressively ‘huge’ sounding and certainly not just for its size.
The other characteristic that came to the fore early on was depth; image depth. In fact, this depth allied to the sheer beauty of the string tone on an album of Maria Bach’s chamber works on the CPO label via Quobuz was among, well, the best I’ve ever heard in any of my living rooms; truly special.
In fact, I mused to myself, this was great artisan tube amp-level staging and tone. How do I know? Please see great artisan tube amp (the Hashimoto-transformered Airtight ATM-1S) sitting next to the Enleum in some of my pics! [Of note, shortly before this review ‘went to press’ I had occasion to audition both the First Watt F8 and SIT 3 amplifiers with a Shindo preamplifier about which more in a future review, but neither amp/pre combo could quite match the Enleum 23R for scale and image depth or for that matter, bass weight].
Yes, there was terrific bass, and an expansive stage lit up by instrumental reverb that abounds on Masabumi Kikuchi Trio’s austere and angular Ballad #2 on the album Sunrise’. The track ‘sticks and cymbals’ from same contains more than sticks and cymbals (oh- I see what they did there!), and the Enleum has a way of allowing through the full shimmer of a cymbal and the wood beneath the ping of firmly struck piano key without ever turning on you. The instrument sounds like you think it ought to with enough silver, though without a hint of sharpness. Again here, the scale was, for a piano trio recording anyway, simply epic. Wow. The Enleumonly stands small, it does NOT play it.
With this self-same material, the Air Tight/Townshend Allegri+ autoformer pre combo had an even more pitch black background, more resolution- and get this, wasn’t quite as overall tonally warm as the Enleum (though that could later be altered with NOS tubes I received). I felt the Townshend/Air Tight ATM 1S surpassed the Enleum in instrumental separation and edge definition, if not necessarily in scale, giving each player their own part of the stage with their own spotlight. The presentation overall, however, seemed a bit less atmospheric. The Enleum’s stand up bass playing was a bit weightier and ballsier still, though this was likely the Allegri’s influence as it may have a slight tendency to highlight detail and clarity at the expense of some mid-bass heft/warmth. It should be noted I was also (initially) running Mazda 12Au7 tubes in the Airtight (it takes two of these and a 12ax7 along with its EL34s), and those Mazdas tend toward the lit up n’ detailed side of things. I would later come to prefer an RCA Command 5751 12AX7 and a pair of Cifte 12AU7s
Yep, the artisanal tube amp with the autoformer pre-played it more precisely than the 23-R. I think here, as I say, I actually preferred the Enleum’s looser, somewhat warmer rendition; sort of found myself wishing the Townshend had some tubes in there at times or that I had re-tubed the Airtight with NOS tubes, etc. (which I later did). Soon I will, in fact, have a great tube pre for the Airtight here, and that might make for an even more interesting comparo! Yup- a good tube preamp for the Air Tight might have brought forth more warmth and ease than the Townshend, as well as more downright impact, but then, of course, we’re talking another five or six grand; essentially another whole Enleum. AND the Airtight takes a good 45 min to an hour to come on song, gets much hotter than the Enleum, and weighs about 50 pounds. It is certainly even less home theater friendly to boot:) [N.B.: It did eventually make for an interesting pairing and the Shindo Aurieges/Airtight combo is truly a great one though the above comparisons still mostly hold with the exception of a bit more warmth coming to the proceedings].
Warm, atmospheric, deep, and enveloping. That’s how I’d describe the Enleum playing jazz pianist Bob Stenson’s Goodbye album on the famed ECM label with Paul Motian on drums. The sweep and space of the proceedings just oozes and flows through the little gray-black brick. The Rejcha piano trios on the Supraphon label were positively jewel-like and ebullient, with the Enleums signature hint of warmth and graceful tone all around and about the Guarneri Trio Prague. You can listen for hours to the 23R, and I often did.
The subtle microdynamics and percussive effects in Ahmad Jamal’s Pots en Verne from the album ‘Marseilles’ streamed via I2S on the KTE May from the Rose 250b streamer/DAC I had on hand for a time, was something to hear, as was the easy dynamic build and sheer image size and density. Among the best sounds, I’ve had in my home. Truly. The depth on display here was also typical of the Enleum aethos throughout its stay with me.
The purity of voices and textures of strings was truly striking on the Bach-Abel Society’s ‘Les Ombres’ album via Quobuz. This was certainly Boazu and Airtight-level grainlessness and texture. And as with the Enleum in general, there was a certain satisfying image density and presence to the proceedings that said at times through the Devore Super Nines, ‘this might be happening on a stage over there right now!’
The black brick did not quite have the jet blackness of background of the Lejonklou Boazu or the Air Tight ATM 1S, or perhaps quite the resolution of either. Felix Mendelson’s piano trios played by the Guarneri Trio Prague had a bit more texture and dynamism when played by the Airtight amp with the Rose 150b performing digital pre-duties and feeding I2S to the KTE May dac.
I would say the Enleum is slightly warm, and perhaps there isn’t quite the midbass definition of my Boazu or the Air Tight amp (at least with the Mazda tubes), but it’s always superbly impactful and deep and never bloomy or one-note. In operation, such things don’t really present as ‘issues’ so much as observations or parts of the Enleums signature charm.
One actual caveat for me was the relatively large steps between volume increments. Soo In tells me given that this is a variable gain amplifier utilizing software control of volume steps and not one with a traditional attenuator, he could have specified the steps to be essentially any interval of dB (as mentioned above. it’s capable of something like 1024 discreet steps), and for me, the current intervals were juuuust a bit large.
My ideal Enleum would have smaller increments as I sometimes found myself having to use the volume slider on my software to get just the right level late night or what have you. I never ended up using the headphone amp, even though it’s widely lauded, as I simply don’t listen to headphones. Though I do own an ALO Studio Six headphone amp and a Schitt Mani as well as a Monoprice THX 887 amp, I’ve never been one for a concert that only takes place only between my ears, no matter how sonically superb.
‘F#@% it, I like it!’
–Lana Del Ray
Yup. what Lana said!! With the sole exception of smaller/more numerous volume steps (don’t think I need full 1024, but yeah, I think I’m the first to ‘complain’), it certainly could be mine, and I may yet force it to get along with its brother in minimalism, the Boazu.
Overall, like my Holo KTE May dac, I’d say the Enleum paints music with a bit of watercolor and light rather than stark raving acrylic, which is right in line with my personal preference, though, it presses the brush firmly, clearly defining every outline and nuance. And the energy, bass weight, depth, and sheer scale it infuses the musical proceedings with is something to hear!
While the overall tone is slightly warmer, there isn’t really any sense of any lost detail or bloated bass. It does have some ‘tube like’ sonic characteristics, but those are certainly not the ‘ol’ timey’ ones; the amp is defined, detailed, and sonically ‘raw’ and real when necessary.
You need the right speakers for this amp and the right cables. You want a syrupy sound? Pair it with really warm speakers or some older Cardas cables– or both. But with anything from a Focal to a Devore to a B&W, at sane levels with a solid source, you essentially have some of the best sonic features of great tube amps like the Airtight along with the rawness, punch, and leave-it-on-all the-time reliability of excellent solid state. I think designer Soo In’s old Nagra gear can safely remain in storage.In sum, the Enleum is a beautiful balance of life, light, and human warmth, which will find a (very small space) at the heart of many a music lovers’ system, to be sure! As I type this, I’m considering adding it to my own.
I bid you peace
25 watts (8 Ω, 1 kHz) | 45 watts (4 Ω, 1 kHz) | 4 watts (60 Ω, 1 kHz)
22.5 dB max (Speaker, Headphone High) | 7 dB max (Headphone Low)
MPU Controlled Stepped Attenuator
10 Hz ~ 100 kHzINPUT IMPEDANCE
10 kΩ (Voltage) | 10 Ω (ENLINK)INPUT
2 Voltage (RCA) | 1 ENLINK (BNC)OUTPUT
5-Way Speaker Binding Post | 1/4″ Headphone Out USER INTERFACE
One Button & Gain Phase Control | Remote ControllerPOWER CONSUMPTION
30 watts (Idle) | 100 watts (Max)DIMENSIONS
230 mm (W) x 230 mm (D) x 55 mm or 82.5 mm incl. Isolation (H)WEIGHT
4.0 kg (net) | 4.5 kg (shipping)
David’s Associated Equipment
Mac Mini 2014 w/Roon and Audirvana Studio; Holo Audio KTE May DAC
Lejonklou Boazu integrated amplifier; Airtight ATM 1S; Goldpoint passive attenuator; Townshend Audio Allegri+ autoformer preamplifier
Devore Super Nines
Skywire 1400 interconnects; Linn K20 and K400 speaker cables with Boazu; Dueland DGA 16 and Skywire 1400 speaker cables (with Enleum); Audioquest Carbon USB cable
Symposium Svelte Shelf Plus and Rollerblock jr. footers (under Holo KTE May DAC)
Stereo Times Masthead
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David Abramson, Tim Barrall, Dave Allison, Ron Cook, Lewis Dardick, Dan Secula, Don Shaulis, Greg Simmons, Eric Teh, Greg Voth, Richard Willie, Ed Van Winkle, and Rob Dockery
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