Signal Path Question

ChrisH · March 27, 2020, 8:55pm

I’ve been dabbling with Roon for a few months now, and am still learning a lot about it, only this week grasped that all my different devices could be their own end points rather than just my main hi-fi. Dumb I know but I’m learning as I’m going!

I had something strange earlier which I’ve been struggling to work out, hopefully someone will be able to give me some guidance.

On my Windows PC I was playing back from my local library 16/44.1 using Roon, outputting through a Dragonfly Cobalt to my Audeze headphones, Audeze DSP filter applied.
Signal path ( after a bit of fiddling) showed lossless, the Dragonfly and Audeze product images showing which I was strangely really excited by.

I then switched to my Moto G5 Android phone, outputting again through the Dragonfly -> Audeze headphones and I got the following signal path:-

I have no DSP activated yet I get these strange up sampling/downsampling items, with no outputs via Dragonfly /Audeze, and a high quality signal path rather than lossless.

What is happening to the signal here?
Why is Roon not seeing the Dragonfly or theAudeze headphones?

Any advice will be gratefully received!

mjw · March 27, 2020, 9:17pm

That’s because it’s an Android device and the OS will max out at 96kHz. Since Roon does a better job of upsampling/ downsampling it does this for you.

ChrisH · March 27, 2020, 9:27pm

Thanks @mjw, but it was only a 44.1/16bit to start with, why is it not maintaining the same signal? I haven’t asked it to upsample to 96kHz…
And Why does it go from 16 to 64 bit and then back again?
And any ideas why the Dragonfly and Audeze’s aren’t identified and showing?

Sorry, probably too many questions…

mjw · March 27, 2020, 11:04pm

Because Android would upsample to 96kHz regardless. The 64 bit float to 16bit is done to maintain precision in the signal path whilst doing the conversion.

The DAC isn’t seen by Roon only Android Audio. It’s the same with iOS.