How Are My Red Book 16-bit Files Being Converted to 24-bit?

Core Machine (Operating system/System info/Roon build number)

Nucleus Rev. B

Network Details (Including networking gear model/manufacturer and if on WiFi/Ethernet)

NETGEAR Nighthawk AC1750

Audio Devices (Specify what device you’re using and its connection type - USB/HDMI/etc.)

PS Audio DirectStream DAC from Roon Nucleus via USB cable and controlled by a 5th generation 32GB iPad Air

Description Of Issue

I was hoping that someone here might be able to tell me how my standard 16-bit files are being converted to 24-bit files. The screen on my DAC shows 16-bit while nothing is playing but as soon as I send a Red Book file though it, the screen shows that it’s a 24-bit file. I checked with PS Audio and they confirmed that it wasn’t being converted by their DAC and that it was due to some setting in Roon.

Could you post your signal path please?

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Sure, here it is.

Turn off all DSP and see if it stops.

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Since you are doing volume leveling, Roon changes the bit depth because doing that (or any other DSP processing) in 16 bits would reduce sound quality. Roon actually does all the processing in 64-bit floating point, as you see, but the DAC can’t accept floating point so it needs to be converted to integer, and Roon does that to the highest bit depth that the DAC can accept, typically 24 bits, sometimes 32. It’s all to preserve the best quality of the volume adjustment.

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Volume leveling is DSP.

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OK, I’ll give that a shot and report back.

Thanks Anders, that took care of it! :+1:

That was my point, but evidently you didn’t like my response??

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No sorry, I didn’t know that volume leveling is part of DSP. I tried to change my response to your post when I realized it, but I couldn’t get it to work and so I just deleted my post.

Thanks for your help, Jim!

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