If your speakers are 8ohms as most are, then you need to look at Sensitivity spec, anything 90dB and up is no problem at all to normal volume in small to medium room. My speakers are 89dB and I never needed more than -10 on volume orb.
Warning: What you never want to do is to go over +5dB, it is very loud, and that's where distortion starts, it can damage your speakers.
TT2 has thermal protection, if somehow you managed to overload it it would trip.
In my case, using it with my speakers, is no different than with my headphones, it stays warm to the touch, never hot. Sound that this thing makes is out of this world to everybody in my house, even my cat loves it.
some more info here:
https://www.head-fi.org/threads/hug...official-thread.879425/page-771#post-16091242
https://www.head-fi.org/threads/hug...official-thread.879425/page-480#post-15223674
He mentions these speakers in the second link:
https://www.bowerswilkins.com/sites/default/files/2018-08/803-D3-info-sheet.pdf - their sensitivity is 90dB