How does Leed processing differ? It relies on a smaller increase of bits. Its predetermined attenuation values limit bit increase to 4 or less for 0 to -6.02dB. Then 1-8 bits extend to -30dB with an average savings of 8 bits over standard digital volume. By offering near perfect attenuation of 16-bit signal without loss is how Leedh's digital volume claims to outperform the best analog and digital volume controls.
Lumin decided to first apply this new tech to their X1 flagship streamer and simultaneously to the pure U1 transport since both share the same firmware. It deals with PCM and DSD playback. Obviously DSD requires PCM conversion so for the X1's USB output, Lumin run their FPGA at 353.8kHz to be limited to DSD128. Their CPU lacks sufficient processing power to handle on-the-fly conversion of higher-rate DSD. For the analog outputs, Lumin exploit Sabre's powerful on-chip capabilities to apply Leedh Processing across the whole range of DSD/PCM sample rates.
Lumin's new class A/B amp is fully balanced dual mono for superior channel separation and low output impedance. It is very nicely built and features a big 600VA Plitron power toroid. Voltage and current gain run across three stages of discrete transistors and resistors. The Lumin Amp is DC coupled to avoid signal-path capacitors and promise low distortion and high neutrality. Each channel sees 40'000uF of filter capacitance from 4 x 63V/10'000uF caps. The design also claims an innovate proprietary bias circuit to eliminate crossover distortion while auto-adapting to load/temperature variance for "truly intelligent class A/B management". The power supply runs 13 stages of regulation.
The aluminium chassis is CNC machined from solid billet and matches the shape of Lumin's players. As is company tradition, there are no seams or exposed screws except on the bottom plate. The chassis acts as passive heat sink and turns from lukewarm to very hot depending on load. As the Amp is expected to connect directly to Lumin streamers, it features high input impedance and sensitivity so there's no reason to add a preamplifier. Like most of my power amplifiers—Luxman M800A, SPEC RPA-W3 EX, Red Dragon S500—the Lumin Amp can operate in stereo, dual mono or bridged mode. Unlike my Luxman and SPEC, stereo power is an already stout 160/320wpc into 8/4Ω. 640w/8Ω mono power is thus only really applicable to very low-sensitivity speakers of ideally higher impedance.
