Hey great looking system, I love Audio Gd dacs...they are great! and the mini torii is just sweet looking and great sounding amp to boot. I know when I had mine it took a little while to settle down and I changed my OA3 tubes to some nos RCA ones and that for me made a cheap and nice boost in sound for the less harsh sounding, then I had swapped out the output tubes next for the next nice improvement in sound sorry dont remember which ones. If you have time you can venture over to the decware forums and they have a whole thread to the mini torii and in there are some threads about tubes and the effect it had on the sound.
I would suggest give the setup sometime to burn in and then start experimenting with tube rolling, though I never could wait personally lol.
Anyways great looking system I plan to get the audio gd dac19 in another month or so, I have been eyeing it for sometime now.
Have a great day