SELLS & NILSSON FILTER

摘要

Named after two of its highest-flying engineers, the Sells/Nilsson filter employed in the Nairn DAC comprises a brickwall MR filter running on a SHARC DSP with a far gentler 6th-order analogue filter feeding the output. Distinct from the 8x FIR digital filters used in Nairn's CD players, this IIR filter increases all incoming sample rates to one of two elevated base rates- 768kHz (for 48k/96k/192kHz media) and 705.6kHz (for 44.1k/88.2k/176.4kHz media). The Burr-Brown PCM 1704 DAC will convert data at 768kHz/24-bit but its response is not as extended as expected.