Balanced B1 preamp

Folks, I assembled the Pass DIY class A kit, building two units each used in balanced mode. I'd really like to build a Pass designed preamp but require balanced inputs and outputs. Based on my somewhat simplistic understanding of balanced operation I figure one could use two stereo preamps with the two channels used for the Positive and Negative signals with a common gnd. This would be somewhat cumbersome to operate but no different from two mono preamps.
My apologies if this issue has been addressed before and please feel free to inform me of my ignorance.
Regards, steve
Just curious, what do you use for a Volume control in a balanced system ?
Most studio gear is SE internally with transformer coupled I/O for common mode isolation. Most of the work I've done with balanced circuits was inside of analog oscilloscopes. Not really the same as balanced audio.
What I had in mind was something like this