HPA-23RM Headphone Amplifier by Enleum

Every critical component and circuit in the HPA-23RM works in harmony to provide the utmost headphone listening experience. The HPA-23RM shares the same circuits with the award-winning AMP-23R. Yet the output stage design is new, incorporating ideas from the AMP-23R’s JET2 Bias circuit. It also employs the all-new improved current output circuit from the legacy Bakoon HPA-21. Ask us about the Enleum Amp-23R to power your extremely power-hungry headphones HiFiMan and Abyss.

The HPA-23RM begins with the Ensence module exactly like the AMP-23R. The circuit employs all discrete transistors with zero negative feedback and features an ultra-fast and ultra-wide frequency response. All these advanced technologies are concentrated in the compact Ensence module, which takes an important role in the input stage of the amplifier. This allows a renowned lossless variable gain so that one can fully enjoy the same performance at any gain or volume level.

VOLTAGE AND CURRENT OUTPUTS

Unlike legacy HPA models which only employ bipolar output transistors, the HPA-23RM separately features MOSFETs for voltage outputs and bipolar transistors for current outputs. The voltage output transistors are precisely controlled by a unique yet simplified, efficient version of the JET2 Bias circuit, a direct descendent of the AMP-23R’s output circuit. The current output circuits share similarities with the legacy HPA-21s, but it has been improved with up-to-date circuit enhancements.

ADVANCED BATTERY CIRCUIT

Enleum has been making great use of the battery power supply from early on, with legacy products like the BPS-01 and the HPA-21. With the HPA-23RM, we’ve focused on an efficient circuit design to reduce the total number of batteries and employed the most advanced power supply design with the 1.2 Mhz SMPS power supply and industry-leading ultra-low noise regulators.

SOLID STATE RELAY ATTENUATOR

The HPA-23RM employs advanced solid-state relays in the attenuator circuit and it is proudly Enleum’s first amplifier to enable more efficient and lower noise switching. The AMP-23R’s ultra precision resistor network is carried over and the same gain adjustment method and control software is applied for a wide range of headphones and IEMs sensitivities.

DESIGN HIGHLIGHTS​

The Enleum HPA-23RM is a true feat of engineering and design. It offers the most powerful yet smallest high-end headphone amplifier in a uniquely designed casing. It has been created to provide no compromises and to support both desktop and portable listening for the discerning audiophile and design enthusiast. The clean design is enhanced by the minimalist user interface, and it features Enleum’s renowned quality of design that makes this amplifier a true work of art.

ENLEUM DESIGN IDENTITY

The design identity set by the AMP-23R is brought forward in the HPA-23RM. This clear design identity is inherited from the AMP-23R with the machined waveforms shared together with the faceted volume knob. The internal structure design effectively manages to transfer the powerful circuit’s high temperature to the chassis’ heatsinks. With such studies in minimalism, the HPA-23RM manages to achieve a similar output power to the legacy HPA-21, which is approximately four times bigger in volume.

ULTRA PRECISION MACHINING AND FINISHING

The minimalistic yet refined design is achieved through exceptional expertise. The design requires meticulous and sophisticated engineering methods and must be machined with the mechanical tolerance only possible by world-class machining equipment and technicians. And the finish is created with the finest craftsmanship down to the last details. The chassis’ precision-machined waveforms of the heatsinks integrated down the sides of the amplifier create an organic visual friction.

ERGONOMIC MINIMAL DESIGN

The minimalist design embraces an intuitive user interface, offering a clean and clear layout of the machined casing with a delicate textural finish and a meticulous form. The internal layout and circuit placements also ensure the highest thermal efficiency. Enleum’s minimal design identity is especially represented in the ingenious construction of the bolts, placing and hiding them at the bottom of the product.

AWARD-WINNING DESIGN

The Enleum design heritage is truly unique and recognized – being one of the very few manufacturers in the world to have won and continue to win numerous prestigious design awards. Ever since Enleum has been winning such awards from Red Dot and iF Design awards. The HPA-23RM has continued that tradition by winning the Red Dot Design Award 2022.

https://6moons.com/audioreview_articles/enleum4

• POWER: 1 Watts (Current Output) / 500 mWatts (Voltage Output) @ 30ohms
• INPUT: RCA and 1/8″ Mini Jack (Analog)
• OUTPUT: 1/4″ (Current Output) and 1/8″ (Voltage Output) Headphone Jacks
• OPERATION TIME: Up to 5 hours (Voltage Output) / Up to 3 hours (Current Output) / Continuous with USB C charger or battery pack
• DIMENSIONS: 116mm x 164.5mm x 22mm (w x d x h)
• WEIGHT (NET): 730g