Enleum HPA-23RM Reference Headphone Amplifier

 Introduction

"Enleum" is a combination of the words "Enlightenment" and "Eum" (Korean for "Sound"). You may have heard of Soo In Chae's work under "Bakoon" which was a collaboration between Soo In (founder of Enleum) and Akira Nagai. 

Description

The HPA-23RM (the "R" and "M" being shorthand for Reference and Mobile) is a unique headphone amplifier with two different amplification circuits - a voltage, and current output stage. The voltage stage is a MOSFET output stage based on a simplified version of the JET2 bias circuit seen in the AMP-23R. The current output stage is derived from the HPA-21's bipolar transistor circuit. While this device is not something you would lug around on a regular basis, it is portable enough to be moved around and can be used on-the-go thanks to its built-in battery. Similar in size to a paper-backed novel, the Enleum measures 116mm x 164.5mm x 22mm and weighs 750 grams.

On the front panel, a toggle switch selects gain, while a recessed rotary knob functions as both a volume control and power switch. A 3.5mm socket is mated to the voltage stage, while a 1/4 inch socket is used for the current output stage. A row of LED lights indicate charge status, battery life and operation. 

The inputs are located on the rear panel, with a USB-C socket used for charging, and a pair of RCA sockets and a 3.5mm socket used for the input signal. There is no selector switch, so only one input may be used at a time. If the 3.5mm socket is in use, this is given priority over the RCA input. 

The current-output stage is capable of 1W of power, and half of that into the voltage output (into a 30 ohm load).   

 

In operation

Rotating the volume knob from its resting position to about 8 o'clock brings the unit into standby mode. The LEDs light up to indicate the battery level. The HPA-23RM uses a discrete resistor relay network to control the volume and further advancing the knob unmutes the unit, with an audible click as you move between each volume level. The manual advises you to bring the volume knob back to the standby position before plugging and unplugging headphones to avoid damage to the unit. 

The unit is specified to operate for up to 5 hours of use in voltage output mode, and 3.5 hours in current output mode, which matched my user experience. Thankfully, the HPA-23RM can be charged while in use.

Sound Quality

For the purposes of this review, I used the Enleum with an iFi Pro iDSD DAC as a source. To cover a variety of IEMs and headphones, I tried the Enleum with the Letshuoer S12 Pro IEM, Beyer DT-880 (250 ohm), Drop HD 8xx and the Audeze LCD2.1. 

As a starting point, Enleum recommends that the voltage output be used with IEMs / headphones that are sensitive, or have a varying impedance curve, while the current output be used with headphones that have a flat impedance curve such as planar headphones. This is not a hard rule, and Enleum does encourage you to experiment. Matching a headphone with a varying impedance curve with the current output does result in a frequency response that tracks the impedance curve, which could be either a good or bad thing depending on your objective. For example, the Drop HD 8xx has an impedance peak at about 100 Hz and a falling impedance in the high-frequencies. Listening to these headphones through the current output gives you added bass and attenuated high-frequencies. Unless you are seeking to alter the tone of your headphones, I found following Enleum's advice to give the best results.

Tonally, the Enleum has a slightly warm and organic midrange, while maintaining an airy and detailed treble. The real shocker is the tightness and power of the bass, which is quite impressive if you consider that this is a battery-powered device. On bright headphones like the Beyer and Drop, this does balance things out a bit, although the warm-sounding Audeze sounded great with the Enleum too. 

The Enleum is highly detailed throughout the frequency range and casts a wide and open soundstage, with a sense of dynamic freedom that eludes most headphone amps. From a performance point of view, the Enleum is easily at the very top, outperforming the headphone output stage of the iDSD DAC, or the Vioelectric HPA V281 that I owned in the past. In my view, the Enleum is really in its element when paired with planar headphones.  

The Enleum does have its weak points. Although there is a gain switch, using either the Beyer or Drop headphones on current mode was tricky, with the volume steps being too far apart. On the positive side, the discrete resistor volume provided precise channel balance even at very low volume levels or high-sensitivity headphones or IEMs. I would also have preferred for the voltage output mode to be paired with a 1/4 inch socket too. 

Battery life is a bit short to make mobile use practical and the repeated charging cycles will necessitate regular battery replacement. Thankfully, the Enleum uses a spring-loaded battery holder for its dual 18650 Lithium-ion batteries, which are widely available. Your unit shouldn't require a return home to South Korea for servicing, and battery replacement should be straightforward. 

Conclusion

Despite the high price tag, the Enleum rewards with top-level sonic performance. It is a must-audition for planar headphone users, and does a fine job with dynamic headphones too. Don't let the mobile moniker fool you though, this amp makes perfect sense for desktop use too - Highly Recommended.

A big thanks goes to Cornerstone Audio for making this review possible.

Price : S$ 4,200

Cornerstone Audio

444 Race Course Rd, S21888 (by appointment only)

E-mail : contact@cornerstone-audio.com  

Telephone : +65 8890 4885         

NAD Masters M66 and Dali Epikore 11 - Singapore Launch

2 March 2024

Introduction

Lenbrook Asia launched the NAD Masters M66 flagship streamer/DAC-preamp and the Dali Epikore 11 speakers today.

The Masters M66 is a BluOS streamer and DAC-preamp that features rich functionality and the latest technology in a single box. The full suite of inputs/outputs include a HDMI eARC port, an MM/MC phono stage and four sub-woofers outputs which can be individually configured. 

An ESS Sabre ES9038PRO DAC is the heart of the DAC section, while an ES9822PRO ADC handles analog to digital conversion. 

Sonic quality has been prioritised with physically separated analog and digital sections with independent power supplies, while the volume control is based on a resistor-ladder control circuit. Analog purists would be pleased to know that the M66 can also be operated in Analogue Direct mode which bypasses all digital processing. 

A full-license version of Dirac Live Room Correction and Live Bass Control is included, making the cost of ownership of the M66 a great value proposition. 

The Dali Epikore 11 speaker was launched to celebrate Dali's 40th anniversary. Standing at a proud 160.2 cm tall, this 4½ way design incorporates Dali's EVO-K hybrid tweeter which is a combined soft-dome and planar magnetostatic ribbon tweeter, a 6.5 inch midrange and four 8 inch woofers. The cabinetry work is outstanding and Lenbrook shared that Dali owns its own furniture maker to make their speaker cabinets. 

For the demonstration, Lenbrook paired the M66 with M23 stereo power amplifiers (operated in bridged mono mode) while the Dali was assisted with a pair of REL Carbon Special subwoofers.  

Impressions

Sonically, this system was as big as it was visually imposing. It had astounding dynamics and the genuine ability to pressurise the large showroom space with deep and chest-thumping bass. I was pleasantly surprised that it was equally adept at reproducing small-scale works with finesse and delicacy. 

Soundstaging was outstanding with careful placement of instruments and voices, with good width, depth and height too. Music was reproduced without harshness or grain, even at very high volumes. 

Tonally, the system is on the laidback end of the spectrum although there is plenty of detail in the high-frequencies to balance things out. Although these speakers could probably blow your roof off, they will appeal more to listeners who want a comfortable and non-fatiguing presentation.

Lenbrook also demonstrated the effect of DIRAC as they toggled it on-and-off. The music sounded harsh and the soundstaging lost a great degree of precision sans DIRAC. Having covered DIRAC in the NAD C 3050 LE amplifier, this did not come as a surprise to me. 

Conclusion

This is a system well-worth checking out if you are looking out for a modern and high-end solution to your audio needs. The Masters M66 showed great promise, and the possibility of future software upgrades, or modular upgrades is an attractive proposition. 

 

  

News - Introducing Vivid Audio Moya M1

14 March 2024

Press release

Introducing Vivid Audio Moya M1

A NEW SUMMIT IN LOUDSPEAKER ENGINEERING

For over 20 years, Vivid Audio has developed ground-breaking loudspeakers to consistent critical acclaim. As with any high-end audio company, we constantly seek ways to push the envelope further.

We’re therefore very pleased to announce the introduction of an all-new ultra-premium loudspeaker – the Moya M1. This will be the new flagship of the range. As always, the Moya M1 was developed according to Vivid Audio’s guiding principle – Form must follow Function.

Like many great ideas, the Vivid Audio Moya M1 started as a sketch. Quarantined in a hotel room during the pandemic, designer Laurence Dickie had the time to dream about a speaker that could do it all. The culmination of a lifetime in pursuit of acoustic design perfection.

A loudspeaker so imbued with power and authority that it would handle any and all types of music with effortless grace.

EIGHT DRIVERS TO RULE THEM ALL

The first thing that strikes one on viewing the M1 is the imposing stack of bass drivers – eight legendary C225-100H drivers, each one capable of handling 800W, arranged in a new high-shove configuration. An awesome display of power!

In fact, the low frequency section played an outsized role in the development of Moya M1. During the testing process, a key finding emerged – extending a speaker’s bass response also improved the perspective of the higher frequency bands.

Each pair of drivers is arranged in a horizontally-opposed configuration on either side of the bass module, with magnets united by a substantial steel tie-bar to completely eliminate reaction forces and the need for a heavy enclosure.

The use of Vivid Audio’s generously proportioned reaction-cancelling ports eliminates cabinet vibration and minimises any turbulent effects which may limit low-end linearity.

Of course, any large loudspeaker can play loud. It was also critical to the team that the listener should be able to pick out the subtlest details – even amidst the hullabaloo of an orchestral crescendo or an explosive drum solo. After all, power is nothing without control.

DLC tweeters and computer-optimised filters

The experience is further enhanced by all-new Diamond-like Coated (DLC) tweeters, a material that can be applied to the surface of aluminium domes at a temperature well below melting point.

The contrasting properties between the DLC and the aluminium substrate heightened shear losses and significantly dampened the ‘Q’ of the break-up. A little black magic that goes a long way to enhancing the listening experience!

Thanks to the computer-optimised, passive, hard-wired filters (built in-house), Moya M1 delivers levels of smoothness, accuracy and phase matching once thought possible only with active systems.

Ultimately, the Moya M1 delivers clarity and precision to the Nth degree, while also being able to reproduce rock concert levels of sound in your living room. From an organ symphony on a huge Cavaillé-Coll instrument to low-end bass from a 90s house anthem, the Moya M1 delivers audio thrills at every octave.

MOYA M1 TECHNICAL INFORMATION

The Vivid Audio Moya M1 is a 5-Way, 13-speaker design.

Four extensively braced bass enclosures, each using two C225 bass drivers in reaction-cancelling modes with aerodynamically-optimised bass ports, are complemented by two C175 mid bass drivers, one C100 mid-range, one D50 upper mid-range and one D26 tweeter.

All drivers are developed from our existing drivers and optimised for use in the Moya M1. The speaker makes use of a passive, five-way, fourth order Linkwitz-Riley crossover in three parts, where the mid & high sections are placed well away from bass sections.

The Moya M1 is manufactured entirely in-house to allow for absolute control over every facet of the build process. To meet our exacting standards we craft, assemble and finish each part in-house by hand.

VIVID AUDIO BACKGROUND

Vivid Audio was founded in the early 2000s by Philip Guttentag and Laurence Dickie. From the very start, the pair set out to build loudspeakers that ‘present the original recording, as clearly and faithfully as possible’.

From the launch of the first Vivid Audio model – the Oval B1 – in 2004, they have rigorously pursued this vision and now offer an extensive range of models, from the Kaya C35 to the new flagship, Moya M1.

Guttentag, a trained engineer, brought extensive experience in the retail, acoustic consultancy and distribution fields; Dickie was an established loudspeaker designer with a long and illustrious career.

While working for British loudspeaker manufacturers, Bowers and Wilkins, Laurence Dickie pioneered the “Matrix” loudspeaker bracing system that is still used in the majority of loudspeakers today. He was also behind the development of numerous iconic designs, including the B&W Nautilus, considered one of the finest loudspeakers in the world.

The Nautilus introduced the concept of tapered tubes to the audio world. This ground-breaking innovation prevents the sound waves at the back of the drivers from distorting the signal and is now a standard feature of all Vivid Audio models.

More information can be found here:

https://vividaudio.com/media/

https://vividaudio.com/vivid-technologies/