This isn’t really a technical question…more of an philosophical one.
Unlike some other software vendors, we have not chosen to market digital volume control as an enhancement. Instead, we work to make hardware volume controls more accessible, so that the people making the audio hardware can fully control how things are done.
This is done in part via the Roon Ready program, which has opened up network control of volume on dozens of products, and in part via our extensions APIs, which allow custom volume control implementations to be plugged in.
Think about how this fits into the 30,000ft view of our architecture/philosophy: media server in the closet dealing in the domain of data only–not audio, endpoints connected via the network, with audio hardware manufacturers owning everything related to sound quality. In that context, I think it should be clear why we have chosen to nudge people towards using the volume controls on their hardware instead of ours.
Of course the world is more complicated. Sometimes we need to do volume control. Sometimes we own some of the code at the endpoints. We have DSP features in the core, …
That said, our software volume control is done right, like the others. 64bit internal processing, dithered, with bit-depth expansion. From a technical standpoint, it’s a fine volume control implementation. If it improves convenience or makes more sense in your setup, go ahead and use it.
Is there a difference between Headroom Management and DSP Volume* in this regard (SQ)?
The code is different, and the location where it it runs is different (endpoint vs core), but the approach is the same. They should sound the same.
Is there a difference between different RoonReady Endpoints?
Is there a difference between different RoonReady DACs?
Yes, lots. Some of them expose our digital volume control implementation to the user, some have built their own, some use an analog volume control, some control volume by speaking to the DAC chip. Some offer multiple choices to the user. There is one with a stepper actuated knob on the front that eerily moves when you change the volume in Roon. This is an area where manufacturers take ownership of their product designs.
What is the case when using a PC Roon Endpoint with Volume enabled DACs (HTPC all in one – USB --> DAC)?
What is the case when using a PC Roon Endpoint with an HDMI AVR (HTPC – HDMI --> AVR/Processor) or a DAC that does not have analog Volume control?
If you choose “Use DSP Volume” then our digital volume implementation is used. If you choose “Use Device Controls” then we’re sending commands to the audio driver. What it does with them is up to the driver + device implementation, and varies a bit, so I don’t want to generalize.