Lumin U2 Streamer

A high-end streamer with digital volume control, Roon Ready, built-in network switch for NAS, and new internal linear power supply.

After the success of Lumin's single chassis, high-performance products such as the T3 and P1, these Hong Kong–based digital masters bring their low-noise, highly musical designs to a single chassis high-end streamer. 

The all-new for 2023 U2 sits between the U2 MINI and the U1, and has the same high-end chassis construction as the top-flight products. The PSU may be internal but it is a well-shielded linear power supply based on a high-quality toroidal transformer. 

The U2 uses Lumin's latest processor, bringing tremendous upsampling flexibility. An optical fiber network jack provides complete isolation from network digital noise. There are three USB ports including a dedicated low-noise USB audio output. The other two can be used for thumb drives, hard drives, and other music storage options. 

A built-in network switch allows you to connect the U2 to your router using, say, the optical network, and connect to your NAS using the RJ45 connector.

Lumin's celebrated LEEDH digital volume processing allows you to eliminate a preamp and connect your DAC directly to a power amp. LEEDH processing is totally lossless and both Upscale crew and customers report that it sounds fantastic.

LEEDH Volume Control

Lumin’s LEEDH lossless digital volume processing was a major upgrade delivered free over-the-air to all Lumin products. LEEDH is a significant improvement over a traditional digital volume control design. Some Upscale customers and employees have even removed preamps from their systems, finding LEEDH to be better-sounding than the analog volume knobs.

LEEDH processing is roughly analogous to a resistor ladder volume in that there is a set of specific steps of loudness from silent to 100%. These steps are calculated to be where the digital attenuation results in an exact answer. As a simplified example, it might choose to divide 15 by 3 and get 5.0, rather than 14 by 3 and get 4.66666666667, which is truncated to 4.66 by "throwing away bits."

LEEDH processing preserves detail, dynamics, and transparency even at low volume levels—without the resolution loss of traditional digital volume controls. Found in ultra-high-end products like the $72,000 Soulution 760 DAC, Lumin brings this advanced technology from their flagship X2 all the way down to the D3.

The Upscale View

Lumin is THE brand for hi-fi enthusiasts who don't need touchscreens, knobs, and a host of extra features. With its background in broadcast engineering, Lumin epitomizes providing the lowest noise and most stable, high-bandwidth circuits. On a Lumin, everything extraneous can be turned off: unused digital outputs, unused processing streams such as Roon and Lumin streaming, the display, and even the RJ45 LEDs. The result of this tight focus is a light, lithe, airy sound with a huge, natural soundstage, and no artificial warmth or bloom.

Sure, the Lumin app takes a little getting used to, but once you're comfortable, it's fast, stable and most of all, sounds the best.

Features

• Dual-network interface with built-in network switch
• DSD512 and PCM768 playback
• Four exceptionally low-phase-noise crystal clock oscillators
• New surface finish taken from the high-end P1
• Leedh Processing lossless volume control

Specifications

Playback Resolution: Up to DSD512, up to 768 kHz, 32-bit PCM, MQA Decoding

Digital Output 
USB: DSD512, 44.1–768 kHz, 16–32-bit
Optical, Coaxial RCA, Coaxial BNC, AES/EBU: DSD64 (DoP, DSD over PCM), PCM 44.1kHz–192kHz, 16–24-bit

Network: Industry-standard SFP, 1000Base-T Gigabit Ethernet

Power Supply: Internal toroidal linear, Low-noise linear regulator

Dimensions (WDH): 13.8" x 13.8" x 2.4" (350 x 350 x 60.5 mm)

Weight: 13.2 lb. (6 kg)