DSP Up-Sampling features in Roon 1.3

[brian (Brian Luczkiewicz)]

@dabassgoesboomboom

Hi @brian what have you found with the the Dacs of popular AVRs and how they up sample internally?

AVRs tend to have lower-end SDM-based DACs (and lots of them to support all of those surround channels and extra zones). I would try targeting their highest supported rate first.

@Driftwood

Does Roon support both 44.1kHz and 48kHz multiples for DSD? Or does DSD upsampling always use a multiple of 44.1kHz?

44.1 multiples only atm

@Matt_Simpson

I have a question about the resource consumption of the DSD upsampling filters. I’ve read that with DSD128 as opposed to single rate DSD, DACs can move down from 7th to 5th order without allowing noise in, yet be more resistant to dropouts and performance degradation.

7th order is empirically more processor intensive than 5th order. It does more arithmetic operations per sample. It’s technically more accurate, and has a lower noise floor.

That said, most of the CPU load involved in DSD upsampling is not in the SDM–it’s in the PCM-domain upsampling stage that comes before it. There is no CPU usage difference between min phase and linear phase. The best way to reduce usage is to target a lower sample rate.