FYI, if you keep using your D30's RCA output like before, then the L50 will play exactly as loud as your Atom Amp as both have around 13dB gain in High gain.
A meaningful bump in volume would only come if your switch to the D30's XLR output with the L50's matching TRS input as the E30 will send a 50% louder Line signal that way.
If you're listening to locally stored tracks, I'd recommend you check their dBTP levels and make sure that they're close to 0dBTP.
Anything below that will waste headroom and make playback quieter with no upside.