DSD + equalizer

In earlier versions of Roon, I seem to remember the playback chain clearly showing a conversion to PCM just prior to implementing an equalizer step.

In the current version, the conversion to PCM is missing:

… though it is FOLLOWED by a SDM modulation.

Can someone explain what’s happening here? i.e., is the equalization now being done WITHOUT converting to PCM, or is the conversion still happening, but just hidden - either by design or by accident?

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And only for DSD256 and DSD512:

For DSD64 and DSD128 it’s ok .


Only @brian :wink:

We released support for native DSD processing in mid-2017, IIRC. The signal paths are correctly reflecting what is going on–there is no decimation to PCM involved.

The DSD64/128 signal paths from @Katun look wrong to me–it shouldn’t be dipping down to 352.8kHz there (@vova, please track this).

Maybe Roon believes the server doesn’t have the horsepower to upsample DSD64/128 to DSD256, and disables native DSD processing?

No, we don’t have logic like that. It feels like a mis-handled case in the SRC planner to me. Normally in PCM->DSD upsampling cases, DSP is inserted at 352kHz, before taking the “big” upsampling step to DSD. It feels like that logic is being mis-applied to DSD source material, causing an unnecessary (and inefficient) down->process->up.

That’s wright !

What’s wrong ? Why does roon convert DSD64 to DSD256? In the DSP settings there is the default for DSD64?!

What about other users? @jhwalker ?