Enleum AMP-23R Integrated | REVIEW - Part-Time Audiophile

Enleum AMP-23R – Introduction

The Enleum AMP-23R (website) is a product you likely aren’t familiar with unless you’re deeply invested in headphones. You might recognize the name Bakoon (website), however, which was the previous name for Korean designer Soo In’s current-mode amplification products. The Enleum is a newer and somewhat different iteration, though with some familial resemblance to the AMP-41R John Richardson has previously reviewed.

Words and Photos by Grover Neville

For those of you who follow PTA — firstly, thank you it means a lot — you may have noticed more than a little ink spilt over Ampsandsound recently, with Dave McNair now the proud owner of a pair of Bryce monoblocks and a pair of Zions, both of which I have reviewed previously. These amps, alongside Acora Acoustics, Sw1x digital converters and a few others, can be counted as those very rare audio products which immediately show themselves as quite special. All of them have elicited a first listen wow response which is rooted not in audiophile fireworks but deep musical capability.

Cue now the Enleum AMP-23R, and in my usual fashion of being allergic to burying the lead, the addition of another product to this special category of musical superstars. When I first spoke with Soo In of Enleum about reviewing the product, he was very friendly and asked me specifically if I would speak not only to the headphone capabilities but also the two-channel use. Much has been said about the headphone capabilities of this amplifier, and my findings line up generally with much of what has been said, so in this review I will speak mostly to, well… speakers.

Build

The price tag of the Enleum AMP-23R comes out to $6,250 USD, and it provides a specified 25W of power per channel into 8 ohms. Enleum told me that the topology is a voltage input with the RCAs, which is processed as a current signal in the middle gain stage and then a voltage output stage couples to the transducer. The BNC inputs are a special ENLINK connector which allows current input, built to work with future source components. There is also a pair of speaker terminals, and on the front a headphone socket. The front panel also includes a volume knob with an interesting mechanical volume pot position indicator, an input selector which can switch between the two inputs as well as activate both simultaneously as well as power the unit on and off. Overall, the unit is tidy and general more the size of a desktop headphone amplifier than a speaker amplifier.

Unboxing is a simple but elegant affair which includes a few nice accessories, most obvious of which is a hefty and nicely design custom metal remote. Build quality is superb and feels somewhat futuristic, with all metal soft to the touch and colored a sort of deep blueish grey. I find the unit understated and pleasant to look at, with minimal LEDs other than input indicator. In terms of functionality, the aforementioned input selector and power button works well, though I did notice that with hot signals especially the volume pot does click a bit as any resistor attenuator volume control will, and there is occasionally some clicking through the speakers with high voltage output DACs. I didn’t find this behavior troublesome, but I did find it went away using a DAC which was closer to 2V or attenuating hot source outputs a bit.

Speaking of hot source outputs, even in my studio, where volume control is set digitally by an interface and a fully balanced DAC output voltage, there was never even a hint of clipping. From modest MC phono stages to balanced or even professional voltages, the Enleum AMP-23R never broke a sweat and never sounded overdriven or compressed. This is a good indicator it will work with a large variety of sources.

Sound

My first experience hooking up the Enleum AMP-23R was exciting. I’ve recently been working on rearranging my home, and have been living with my trusty Proac D30RS hooked up to a Schiit Vidar. This is not a bad amp by any means, and in fact I’ve had several satisfying listening sessions with it. But after having lived with Ampsandsound and several other very special tube amps, it was certainly not as dense or rich as those experiences and I found myself missing said tonal goodness.

Enter Enleum AMP-23R, with an antidote. What I hear on first listen is a vividness in the phantom image which I typically associate with high end speakers and plenty of current. The image has depth, width and that sensation of three dimensional energy that I more often associate with great tube amplifiers than solid state. My ATC SCM20s, Proacs, and a recently arrived pair of Sound Kaos bookshelves all disappear completely, both in my untreated living room and my nearfield studio setup.

In the low end I hear a slight warmth and bump around 60-70 Hz which creates a pleasing sensation of impact, without being overwhelming or unbalanced. In the top end, a combination of extraordinarily quiet background and slight darkness made it so no recording, even particularly edgy ones were ever harsh. The Enleum AMP-23R is remarkably quiet, and remarkably clean, reminding me of my time with the Ampsandsound Zion more than my time with other solid state amps. While I don’t think it scales the heights of the Zion, the midrange clarity and definition are astonishing.

The Enleum AMP-23R also has, alongside that slightly warm tone, a very lively and dynamic style which means the amp does not come off as overly warm or syrupy. This is less romantic sounding than a tube amp, but it channels the liveliness of SET, with a bit less overt color. Dynamic program material is fast and liquid smooth in a way I’m not used to hearing often, and especially from little amps like this.

Headroom is the term that comes to mind. It’s as if all the benefits of high power such as liveliness, dynamics, clarity, are combined with a just a sprinkle of great tone and a superbly quiet background. This makes for an amp that draws my ear to the pace of fast, bright material and also to the sensitivity and phrasing of softer material. I was never lost in the sauce noticing plankton either, as little details were noticeable but fit into a very cohesive musical picture. Lead instruments and vocals were at the forefront and supporting sounds were arranged around them, again speaking to the Enleum AMP-23R’s capability for three-dimensional imaging.

When it comes to power, for my relatively modest listening levels and more efficient speakers, I had no problems. Although the midrange seemed electric with the kind of current and headroom I associate with big power, and the frequency extremes were perceived as wide and extended, when I put the amp up against 87 dB speakers, and moved up fairly high on the volume pot, I could start to hear some limitations. Not in the way the Enleum AMP-23R performed explicitly, but rather as a sort of lack of absolute authority which I have heard from much more powerful amplifiers.

With that said, I was more than a little surprised by the performance of the Enleum AMP-23R. It drove speakers to levels I did not expect at all, and if I’d been asked to guess the power of the unit during my review period, I would have confidently said it was a strong 70-90W performer at least. This mirrored my experience with the Naim Uniti Nova. The Nova, while not the last word in watts on paper, had a muscular solidity to its sound that gave the impression of a much stronger amplifier than you might expect based on the spec sheet. In any case, it drove all my speakers with ease.

If it sounds like I’m being a bit nitpicky, know that this is only because this amp is so phenomenal, and really does exceed my expectations for what a 25W desktop-size integrated can do. And I don’t mean that in a reviewer-hat, love-new-toys-and-advertisers kind of way. I hope it’s clear by now that the Enleum AMP-23R sounds very very good, and while I’ve been busy with adventures in Europe and exciting creative projects, this little amplifier has drawn me into more listening sessions in the last month than I’ve had since the Ampsandsound Zions were in my system.

Oh, and remember I mentioned this amp works with hot sources? Well, for those with a DAC capable of adjusting the output voltage, since the amp will take very hot signals, you can turn the input up a little more than you typically might for an extra sense of punch and authority. Just a handy tip for those who want an even more authoritative sound.

Headphone Sound

And now the headphone performance — it’s superb. The tonal balance is similar to what I noted for speakers, with some warmth in the low end, and a hint of darkness in the treble. However with headphones the effect of this is that the Enleum AMP-23R gives the impression of a little more depth and weightier low end.

Headphones tend to smooth out the broad tonal balances of electronics circuits, so the little Enleum AMP-23R generally sounds more linear with headphones, but those liquid smooth mids, and vanishingly low noise remain. What also remains is that electric sense of dynamics and also an authority even at low volumes.

This brings us to great pairings — the most popular and obvious is the power-hungry Susvara from Hifiman. The Enleum AMP-23R drove these headphones with ease, and was my favorite amplifier for these headphones I’ve heard so far other than the Ferrum OOR + Hypsos. The Ferrum leans more neutral and linear, but the Enleum has more warmth and impact, and the slight bass lift actually makes these headphones sound even more balanced in some ways. The soundstage is also more three-dimensional and dynamic with the Enleum.

On other headphones from Audeze and Dan Clark Audio such as the LCD-4 or Ether 2, this warmth again balances well, and overall this is a dream of an amplifier for planar magnetic headphones. On dynamics it fares well, such as with the FOCAL Utopia or Sennheiser HD800, the top end is never harsh and has a kind of smoothing effect that I found pleasing with Focal headphones especially, which can tend towards being a bit forward.

Enleum AMP-23R – Conclusions

I mentioned at the beginning that the Enleum AMP-23R falls into the category of gear that sounds rather special to me. While it isn’t dead neutral, it represents a more linear take on the arresting and engaging sound I value than a tube amp would. For those who have purchased this for the headphone output, you’re doing yourself a disservice if you haven’t tried it with speakers.

That said, if you are looking at this as a headphone amp with functional speaker outputs, I would argue this is doing Enleum a disservice. The Enleum AMP-23R is tonally one of the finest solid state amplifiers I have heard, and those looking for deep musical involvement would be well served auditioning one. If you don’t require gobs of power, you’ll have a hard time finding a solid state amplifier under $10K that’s anywhere close to as rich and clear sounding AMP-23R.