B50 Low Volume, pop/crackle, then working normally?

First time using brand new unit. Got really low volume out of turntable. Didn’t test long though. Couldn’t get HDMI or optical to work from a TV source. Then hooked up a CD player into line in. Again, super low volume even cranking the knob and remote volumes. Stayed like that a minute, then all the sudden some huge crackles/snaps/pops, and volume went full on! Was not happy with that for my speakers. Seems to be functioning “normally” now and can ramp volume up/down at respectable levels.

Is something wrong with the unit, or do these op-amps need an initial burn-in period?