Lumin P1 Music Server/DAC Lab Report

Lab Report

Comparisons with Lumin's more affordable D2 music server/DAC solution [HFN Jul '20] are not especially instructive because the latter employs the Cirrus Logic (née Wolfson) WM8741 DAC while the P1 uses pairs of ES9028PRO converters. Maximum output is a healthy 5.8V from a transformer-coupled stage with a usefully low 18ohm source impedance (balanced XLRs) while the A-wtd S/N ratio is a very wide 118dB, via all digital inputs and over all sample rates. Distortion is exceptionally low too with just 0.00006-0.0003% achieved between 20Hz-20kHz at its peak output [see Graph 1, below]. Neither does Lumin appear to be using one of ESS's seven 'baked in' digital filters – instead, the algorithm, with a slow-roll off/linear phase profile, appears to be adaptive, responding differently to continuous and transient signals. Stopband rejection is 50dB (re. 20kHz at 48kFs) while the responses have a slightly early pre-Nyquist roll-off of –1.2dB/20kHz with CD/48kHz media and –5.1dB/45kHz with 96kHz+ media. Jitter, meanwhile, is vanishingly low at sub-10psec with all sample rates.

The Lumin P1 includes an equally impressive balanced analogue preamp. Gain is ~unity and the maximum input/output level is ~6V, achieving a low distortion of 0.0008-0.004% at 0dBV (20Hz-20kHz). Distortion increases at subsonic bass frequencies, from 0.004%/20Hz to 0.015%/10Hz and 0.15%/5Hz, presumably as a function of the output-coupling transformer [red trace, Graph 2, below]. The response also cuts off very abruptly below 3Hz but is otherwise flat to within ±0.2dB from 20Hz-20kHz before rolling away above 65kHz (–3dB) to –19dB/100kHz [black trace, Graph 1]. Note that the P1's 'CD de-emphasis' function is applied to its analogue inputs [dotted trace]. PM

822lumin.lab1

Distortion vs. 48kHz/24-bit digital signal level over a 120dB dynamic range (1kHz, black; 20kHz, blue)

822lumin.lab2

Distortion vs. freq. (red; balanced in/out re. 0dBV) and freq. resp. (dashed, with CD de-emphasis)

Maximum output level / Impedance 5.80Vrms / 18ohm
A-wtd S/N ratio (Digital / Preamp) 118.0dB / 82.2dB
Distortion (1kHz, 0dBFs/–30dBFs) 0.00006% / 0.0011%
Distortion & Noise (20kHz, 0dBFs/–30dBFs) 0.0003% / 0.0022%
Frequency resp. (20Hz-20kHz/45kHz) +0.0 to –1.2dB / –5.1dB
Digital jitter (48kHz / 96kHz) 9psec / 11psec
Resolution (re. –100dBFs / –110dBFs) ±0.1dB / ±0.2dB
Power consumption 19W (19W standby)
Dimensions (WHD) / Weight 350x107x380mm / 12kg
Price £8495

COMPANY INFO
Pixel Magic Systems Ltd
Hong Kong
Supplied by: Sound Design Distribution Ltd, Cardiff
0800 0096213
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