Any chance the ultra can get higher output voltage?

[pbr]

Yeah I'm maxed out my volume on movies. Pretty simple, HDMI in, low level to powered JBL lsr speakers. Same set up instead of HDMI I used optical into marantz receiver to line level to lsrs. Plenty of headroom. From what I can see it's a 3v output.

Any way to get more?

 

[pbr]

Ok so plenty of volume on all other inputs. The HDMI in with Max hbo streaming stuff like Godzilla isn't loud enough still. Is it because of some surround sound codec that hbomax is sending over HDMI? I thought it was pcm 2 channel