Enleum Amp-23R amplifier is evaluated!

The Enleum Amp-23R amplifier was built for simplicity and a purpose; can it live up to its expectations? Doug Moore explores it with a fine tooth comb!

I have seen many interesting things within the field of high-end audio. One of those things is purpose-built products. These products are built for one thing and do it well. For example, if a person buys a Porsche 911 they know that this car is built for one thing. To give the driver an ultimate driving experience. When people buy these cars, they know that this car will do nothing for them when it comes to taking the kids to soccer practice or taking the family across the states on a trip. People buy this car for what it does perfectly and either live with its shortcomings or don’t care. Another example of this would be a High-end Suit. You might wear this to a business event or a reunion but it would not serve you well to wear this to the gym or the grocery store. These products do what they do better than any other option and are a great purchase if you know the limitations of these products.

I have also had the chance to see a few purpose-built products. I would call a single-ended tube amplifier a purpose-built product. For the most part, these amplifiers are great for ultra-high sensitivity speakers and music that takes advantage of these amplifiers’ strengths in the midrange with “holographic presentations”. People listening to EDM music aren’t likely to choose an SET amplifier. Most SET amplifiers have a bass that is too slow and “bloomy” for this style of music. There are exceptions to this rule and I have heard some of them but most experts would agree that choosing a SET amp for high-dynamic electronic music is not ideal.

However, every once in a while, you come across a product that does what other purpose-built products do without some of the shortcomings associated with products of this type. An amplifier that is built for high-efficiency speakers? check, an amplifier that puts the music and sound quality over the features and design? check, how about an amplifier that is a small form factor, does not get very hot, and is very lightweight? What, about an amplifier that keeps things simple, and you, never have to worry about tube life or bias adjustments? What did you say!!! The Enleum Amp-23R is one such product.

This Enleum amplifier puts out 25 watts per channel into 8 ohms and 45 into 4 ohms. So, choosing the right speakers is critical. With the Amp-23R it would be doing a disservice to this amplifier to try to drive a set of Dynaudio or Magnepan speakers as it does not have the power and is not designed with these types of speakers in mind. I will get to the sound of the Amp-23R below but careful speaker selection is needed to get the most out of this amplifier.

The Amp-23R is a small form factor amplifier that uses a combination of technology and simplicity. The input module of the amplifier is a zero negative feedback design that employs discrete transistors and an ultra-fast and wide frequency response. This module called the Essence module is then put through a gain stage before getting to the output devices, unlike other designs The volume is set between the input and output stages, not at the output stages like most amplifiers. This is a lossless gain stage of very high quality.

The output devices are controlled with what Enleum calls its JET2 bias control. This control incorporates micro processing, analog to digital and digital to analog with advanced software to monitor and set the bias of the output transistors on the fly. It enables the amplifier to be at the perfect bias at all times during operation improving operational efficiency and operating temperature. The AMP-23R also uses very high-quality Exicon output transistors within its design parameters.

While the Enleum Amp-23R uses the same power transformer as their earlier designs it is much more efficient. The same MPU that controls the bias also controls the power supply allowing it to be at the best efficiency at all times while putting out the most power and remaining quiet. I will say that this amplifier blew my expectations away with its power reserves. Only when pushed way past my ability to enjoy the music did it show any strain or collapse of the soundstage. 

Another feature of the unit is that along with the amplifier circuits, you get a top-flight headphone amplifier. Enleum says their 4-watt headphone amplifier circuit in the AMP-23R will power any headphone on the market and while this is not a headphone-dedicated sight I do own a pair of Beloved Grado headphones and the Enleum drove them better that anything I have had them hooked to–even having heard people say they bought the AMP-23R just to drive headphones!

Unboxing:

The AMP-23R was delivered in a well-packed box that protected the unit very well. The unit came with a bag that tells you about how light and small this guy is. You could take it to the office with you if you want to use it at home or the office. The Amp-23R comes with special feet that you install onto the bottom of the unit. These “Base Isolation Devices” as Enleum calls them help isolate the amplifier from unwanted vibrations.

The remote is a very simple and elegant design that I like. This remote allowed simple operation and the only part that took a little getting used to was the input selection but after that all was great.

BACK PANEL

The Amp 23-R’s back panel is very well laid out and nicely labeled. It has RCA inputs, a right and left ENLINK connector for future use with Enleum products, and two sets of speaker binding posts. The power connector allowed me to easily connect my custom-built power cables and my beloved Iconoclast Speaker cables to fit the binding posts perfectly as it did my Iconoclast BAV REL subwoofer cable. I used my Mogami RCA connectors in place of my normal XLR cables from either my DAC or phono preamp.

SOUND QUALITY:

I let this amplifier just sit and play for a few days even though Soo In Chae from Enleum had told me that this amplifier was already broken in being reviewed before. I always want to put some time into a product before s sitting down with it.

When critical listening began, I was very interested in seeing what an amplifier somewhat different from other designs would sound like in my system. A couple of things stood out right away. This amplifier is dead silent, and it does not sound at all like a small form factor 25-watt amplifier.

Sara K’s What matters is a beautiful release from Chesky Records and allows an amplifier to show its soundstage and imaging performance very well which is why I employ it quite frequently in reviews. Every song is a treat and one thing stood out with the Enleum AMP-23R. It is quiet as a church mouse and the soundstage is either as cozy as a singer-songwriter or as wide as an orchestra; it depends on what is being played.

Albums like What Matters, contain both cozy and wide parts. I believe that because of the dead silence, gain control, and processor-controlled bias contrast shows up much more with the Enleum. All music I played through this amplifier showed the contrast with the soundstage better than any amplifier I have heard to date. From single guitar and Sara K’s voice to multiple instruments I felt like the amplifier showcased this perfectly.

Madison Cunningham’s new album Revealer is a really good album for bass and dynamic contrasts. The Enleum Amp-23R did an admiral job of showing this. The Amp-23R while not being a high-powered amplifier must be treated more like a lower-powered tube amplifier or a First Watt design. Both careful speaker and room matching are required to keep both the amplifier and listener happy. The Amp-23R had no issue with this recording at any realistic listening levels and showcased what this album had to offer.

BASS: While this amplifier is a lower-powered design it had no problems moving the 4 15” drivers in my Spatial Audio speakers. There seemed to be a bump in the bass around the 60-hertz region that seemingly gave the amplifier an extra kick. The bass had detail and control that most amplifiers at this power level seem to lack.

MIDRANGE: The midrange on the Enleum seemed to be where it showed its quality. Not unlike many tube designs, the Amp-23R liked the midrange and made it the star of the show. Very detailed and rich would be the way I would describe the midrange. If you love strong midrange performance and listen to music that can showcase this the Amp-23R should be on your shortlist for auditioning.

TREBLE: The Amp-23R has a very detailed yet dark treble response. I know this is an odd statement but let me explain. While the treble response is detailed and realistic the overall character of the treble has a dark tone. Not unlike some tube designs I have heard in the past. The treble doesn’t roll off it just is not as lively or bright as other solid-state designs. If you have speakers that tend to overly brighten up or lean toward too bright the Amp-23R might just be the ticket.

SOUNDSTAGE AND IMAGING:

The Enleum amplifier has no issue with playing its disappearing act concerning soundstage and imaging. This amplifier simply gets out of the way and lets you enjoy your chosen tunes. The soundstage is deep and the imaging is pinpoint. I have no better way to say that this amplifier will simply be as good as your room and speakers will allow and will take you to music heaven if you have your room and speakers sorted to do so.

COMPARISONS:

Other than my reference Pass Labs X150.5 and Hegel P20 preamp I also had the very good Cary Audio SLI-80HS in-house to compare to. I liked all of these amplifiers as they all brought something to the table. The Enleum held its own and showcased a very good frequency balance and tone. Of course, the Pass Labs/Hegel combo was more dynamic and at times fuller sounding it would make sense knowing there are 300 watts per channel to utilize.

The Cary had a rounder-sounding bass with more punch but less detail than the Enleum. Both the Cary and Enleum put midrange first and while the Cary could be more syrupy and rich the Enleum had more detail and speed. The Enleum Amp-23R has some traits that great tube amplifiers have in that the music seems to keep that tone and texture that displays emotion that people connect with. All three of these amplifier combos are great and it will be more of a personal taste on which one you choose.

CONCLUSIONS:

I have heard many amplifiers over the years from huge monoblocks to small combos like the Enleum. If you have speakers that are over 90db efficient and only need 25 watts to get going, I will tell you, you owe it to yourself to take the Enleum for a test drive. This amplifier gives you a great dose of musical emotion, soundstage and imaging, and bass and dynamics well beyond its modest power rating. For the right person with the right system, I would wholeheartedly recommend the Enleum Amp-23R!

SPECS:

GAIN

22.5 dB max (Speaker, Headphone High) | 7 dB max (Headphone Low)

GAIN CONTROL

MPU Controlled Stepped Attenuator

FREQUENCY RESPONSE

10 Hz ~ 100 kHz

INPUT 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 Controller

The System: Speakers: Spatial Audio M3 Turbo S open baffle./ REL T9x subwoofer/ Digital: Denafrips Venus II, / Modified PC-based Music server/streamer. Analog: Vintage Hitachi Turntable, Darlington labs MP-7 and SU-7 phono preamp, Audio Technica VM95SH cartridge Amplification: Hegel P20 preamp. Pass Labs X150.5 power amp. Conditioner: PS Audio Quintet. Cables: Iconoclast SPTPC speaker cables, Mogami XLR interconnects, Iconoclast BAV REL subwoofer cable

PRICE $ $6250.00 CONTACT: https://enleum.com/