No you can’t control the volume RME don’t support volume control via USB. The preamp works on all analogue outputs though so XLR or line I only have the non pro so cant say on digital.
I get around this by using Deep Harmony extension as I have Harmony Hub remote control system and as the RME has an IR remote it can control that from within Roon using the extension.
Thanks. Just started using Deep Harmony and I’m very impressed with it.
And to follow up on my own question about volume on digital out. I have been through the manual and it seems like there is a possibility for volume control on the digital outputs:
“Dig. Out Source
Default, Main Out. Copies the signal Main Out 1/2 (including EQ and volume) to the digital outputs AES and SPDIF/ADAT. Useful when connecting active monitors with digital inputs.”
I use DSP Volume Control (aktiv) in my Roon settings to control the volume of my RME ADI-2 Pro.
Nucleus via USB connected to RME ADI-2 Pro connected via XLR with my WLM Elisabeth active speakers.
I suggest to set the volume control on your RME ADI-2 PRO to max -6dB and control the volume with your ROON frontend.
For me it works fine with no quality impact.
I noticed a difference when ever I use DSP
hi
there is a new firmware (V35) for the RME ADI DAC 2 from 26.03.2021
Biggest change i found, is a improved SteadyClock, filter and phase control. SteadyClock’s jitter filter now operates down to 1 Hz instead of about 200 Hz, thus reduces even very low frequency input jitter efficiently.
the update App is here, took a minute over USB for me without a problem. (from V34 to V35)
https://www.rme-audio.de/adi-2-dac.html
from release note
03/26/2021 ADI-2 DAC DSP 35, ADI-2 Pro FPGA 250 DSP 102. All Pro: improved performance of SRC, headroom reduced to +3 dB. New option ‘SRC Gain dig’ to preserve digital headroom during USB recording and digital loop-through. Pro and DAC with MRC: Over display in level meters now takes actual headroom into account (+2.5 dB Line/IEM, +1 dB Phones). All DAC: When loading a setup, the current sample rate is not changed.
03/17/2021 Digiface USB: v17 supports new PCBs. Devices with V14 do not need to be updated. ADI-2 DAC FGA 35, ADI-2 Pro FPGA 249: Improved SteadyClock, filter and phase control. SteadyClock’s jitter filter now operates down to 1 Hz instead of about 200 Hz, thus reduces even very low frequency input jitter efficiently.
happy easter to you all!
Still looking for an answer to this, if anyone knows, please?
this was answered in a few theads
or here
think its the same with a NUC directly to a RME
i prefer a streamer (Metrum AMBRE) and a coaxial connection to the RME
Thanks, I know it’s possible to connect via USB from NUC/ROCK to some DACs, as I do with my Oppo BDP-105.
However it seemed from other posters as though there might be a specific issue with the RME needing Linux drivers for this purpose (?), so was wanting to clarify before buying the DAC.
i understand
with Linux (R.o.c.k) it should work
they talked about using with Linux in RME forum here
Thanks, that’s very helpful!
Yes you can connect an RME ADI-2 Pro to the USB on a NUC running ROCK - and that will play just fine.
However, a friend and I did blind testing between that configuration and adding a Roon Bridge in between the NUC and the RME, which made a huge positive difference in SQ.
We tested both with Allo USBridge (first edition) running DietPi and a Rapberry Pi 4 running RoPieee - both sounded much better than direct connection. We were not able to distinguish between these two Roon endpoints during our blind tests, so I would really urge you to add an RPi4 in the chain.
Thanks for the heads up.
So to do the update, all I need to do is plug it via USB to cpu?
yes, you need the RME driver on the PC/ MAC and than the little flash program
updating is easy
i can not tell if there is a sound difference, but an improved clock can be nothing wrong 
Thank you. I will try it now.
Done.
I’m looking at buying an RME to replace my Topping DX3-Pro.
A question for owners - does the auto input switching work well, and does it work well with USB?
My Roon is fed via a Pi4 with USB into the DAC, and I also have the TV going in via optical. If the RME can auto-switch between the two when it detects a signal then it’s got 5-star WAF and I’m clicking buy. 
Note: I also have SPDIF via Coax going into the DAC from my (digital) phono stage. So is the USB auto-switching doesn’t work well, sadly there isn’t an option to use coax from the Pi. 
Hi Nic I doe this exact same thing, auto switching works very well. I use it all the time, my FireTV box i connected to it by optical and Rasperry Pi by USB.
Have any owners of these managed to use it to integrate a sub with crossover and volume control (when using direct to a power amp for main speakers and secondary outputs to a powered sub)?