Good morning, I installed Roon on a Mac Mini M1 as an operating system with Sonoma and connected to a DAC (Lector Digitube). I have a problem with the volume, let me explain… I set the volume control to “device” and in the DAC settings the “exclusive” box is checked when I start a song I can’t change the volume either from the PC or from the iPhone ( with Roon Remote installed). The volume remains fixed. If, however, I remove the “exclusive” tick, I can modify the volume correctly but the resolution of the file, even if in high definition (96-192Khz, only comes out in 44Khz. I tried to select “DSP” as volume control, in that case it works correctly, it seems to maintain the resolution of the song. Can you help me resolve this if I want to set it to “volume control from device”? Thanks! Fabio
I am not familiar with MACs or your particular DAC but I believe, the following is probably representative of what is happening.
It looks like the DAC does not provide a means for the MAC to change the volume (If, as it appears to be, it is a pure DAC and not a DAC/Amplifier then there would be no volume control on it anyway). This is why you cannot change the volume when the Endpoint is in exclusive mode and set to ‘device volume’.
When in non-exclusive mode, it is probably the MAC mixer that is being used to control the volume. This will be scaling the samples it presents to the DAC.
Setting DSP volume control on the endpoint will also use sample scaling to control the volume (but done at the roon server) - but, exclusive mode and DSP volume control will not need to downsample the audio to get to the 44.1kS/s sample rate of the MAC mixer and so can maintain the source sample rate as long as that does not exceed the capabilities of the DAC.
In practice, whilst not theoretically as good as direct control of the gain setting of a pre-amp because the dynamic range of the audio signal is being reduced, DSP volume does not observably affect audio quality because the because of the limited audible dynamic range. Either the noise is not audible or a full scale signal on maximum volume is into the pain threshold.
Thanks for the reply, the strange thing is that I also have Audirvana on the PC (obviously not running when Roon is active) and the volume control works perfectly. Another thing, last year I subscribed to Roon for three months and I’m sure that everything worked correctly with the volume control from the device and the “exclusive” option selected, the only difference was the previous version of the Mac’s IOS.
Thank you!