Author
Articles by acwell
Our PCM-to-DSD experiments repeatedly led back to polyphase IIR allpass halfband filters. This note looks at what they do well, where they compromise, and why they fit real-time DSD conversion unusually well.
Fast startup at DSD512 and beyond is not a UI trick. It is a consequence of how decoding, SRC, SDM and buffering are organized before playback begins.
A higher-order sigma-delta modulator is not simply a switch marked “better.” Stability, input level and noise shaping behave very differently as the target DSD rate changes.
Gapless sounds like a checkbox feature. At high-rate DSD it quickly becomes a problem involving conversion state, pre-rendering, boundaries and timing.
DoP is often described as DSD packed into PCM frames. Correct—but that description hides most of the problems a real playback engine has to solve.
The Babyface Pro FS is not designed as an audiophile DAC, yet its engineering priorities make it an interesting reference point for evaluating USB audio on macOS.
