HPA-23RM : REFERENCE HEADPHONE AMPLIFIER
The HPA-23RM is our new reference dedicated headphone amplifier. It is designed for both high-end desktop usage and mobile usage – hence using “R” for reference and “M” for mobile in the product name. Continuing our legacy in the headphone amplifier design with up-to-date technologies, the HPA-23RM follows in the footsteps of the AMP-23R and our other legacy products, such as Bakoon’s HPA-21 and HPA-01M.
The HPA-23RM contains two amplifiers in one package as it employs both voltage and current outputs. The voltage output circuit is directly inherited from the AMP-23R’s latest MOSFETs output stage with a simplified version of the JET2 Bias circuit. While its unique current output is a descendant of the HPA-21’s bipolar transistor based circuit, its modern design is even more refined with advanced technologies.
Furthermore, thanks to the technological advancements in the battery power supply design and efficient thermal design, one can now listen to Enleum’s reference circuits in a much smaller package.
Every critical component and circuit of the HPA-23RM work 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. The HPA-23RM’s novel power supply allows the headphone amplifier to be operated in “R” mode for full output power when powered by external power or battery via USB C. The “M” mode is for more efficient use, powered only by its internal batteries for portable use.
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 our renowned lossless variable gain, so that one can fully enjoy the same performance at any gain or volume level.
VOLTAGE AND CURRENT OUTPUTS
Unlike our legacy HPA models which only employed 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 our unique and 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-21’s, 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. The HPA-23RM runs an external battery or power supply for the “R” mode for full power output, or either on a pure battery for the efficient “M” mode.
SOLID STATE RELAY ATTENUATOR
The HPA-23RM employs advanced solid state relays in the attenuator circuit and it is proudly our 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.
The Enleum HPA-23RM is a true feat of engineering and design. It offers our 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 make this amplifier a true work of art.
ENLEUM DESIGN IDENTITY
Our 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 acheive the similar output power of 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.
The Enleum’s 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.
1 Watts (R mode) / 500 mWatts (M mode) @ 30ohms
RCA and 1/8″ Mini Jack (Analogue)
1/4″ (Current) and 1/8″ (Voltage) Headphone Jacks
Continuous or depending on the external battery capacity (R mode) / up to 5 hours (M mode)
116mm x 164.5mm x 22mm (w x d x h)
- Enleum reserves the rights to change the preliminary specification, upon its initial production release.
Enleum now accepts preorders for the HPA-23RM. Due to current circumstances in the industry, the production quantity will be limited to 250 units in 2022. The first batch of 250 units is expected to start shipping in December, 2022 to those who make a reservation with a refundable deposit, excluding transaction fees. The deposit amount is $500 and the remaining balance is to be paid before the shipment. The MSRP is $3,000 in the United States and is subject to local adjustments in global markets.