Integrated Amplifiers

BluOS is a lossless, multizone and latency-free wireless music distribution platform compatible with native audio files up to 192kHz/24-bit resolution. The technology is an offshoot of Canada's Lenbrook group, best known for the NAD brand which has acted as pilot and flag-waver for the BluOS ecosystem [most recently, HFN Feb '22].

Having established its credentials, BluOS is now appearing in third-party products, including this Attessa Streaming Amplifier from Roksan. Moreover, its strong showing in our earlier reviews seems entirely justified from a technical perspective, for not only is the performance of Roksan's PCM5242 DAC-based digital/preamp board identical in all key respects when comparing 'wired' USB and S/PDIF with wireless BluOS, the latter actually proved superior in its jitter suppression! So while the 107dB A-wtd S/N ratio, the minimum 0.0002-0.0008% distortion (20Hz-20kHz over top 20dB of dynamic range) and the ±0.4dB resolution (100dB range) all prove unchanged, jitter was reduced from 220psec (USB, 48kHz) to 105psec via BluOS [see inset Graph]. PM