Decware ZP3 Phono Stage Gain Issue

Hi There....I have a zp3 phono stage that I've had for a little while but only recently realized there may be an issue with it when I recently hooked it up to a Sonos port after temporarily using a cheaper phono preamp that I got on amazon. The amazon amp is an Emotiva XPS-1 and it is substantially louder, with a lower noise floor, and more clarity. It looks like it the gain is similarly spec'ed  (but I am admittedly not super fluent in specs) so I'm a little confused as the ZP3 gives me maybe about 40% less volume than the Emotiva.

My setup is a VPI Scout 1.1 with a Clearaudio Virtuoso 1 cartridge. I run that through the given Phono stage and into the Sonos Port. Any ideas here on how to get the gain that I'm looking for? The ZP3 volume is just barely acceptable when i have the sonos turned up to max volume and the Sonos input gain set to its highest level, which I assume is why the noise floor is high.

Could it be a bad tube? Is my cartridge just a bad match for the ZP3? Should I add a pre-amp? These are the things I'm considering.