Got the truly wireless Bluetooth modules, FiiO uTWS1 mmcx version to use with my Shuoer Tapes (104db sensitivity) .
These have a lower gain than my Trn B20s. I have to use them at full volume or 1 click from full volume.
I imagine these are setup like the older B20 model. Making them good more suitable for very sensitive iems. They probably will not hiss.
Too bad I don't own extreme sensitive iems.
Probably not the right discussion for this particular thread since it doesn't support 24bit. I did start another thread for this: https://www.head-fi.org/threads/the-tws-neckband-bt-cable-adapter-thread.920709/