if $10k worth of gear cant beat < $1k step #1 is to measure and baseline that it is working even remotely properly. Both performance and settings (eg..; Bias)
PS Audio BHK lacking..
I bought a used PS Audio BHK preamp to replace my Rotel. It sounds thin with no depth & bass compared to my Rotel so I let it run for over an hour with no change. I'm new to tubes so I'm looking for ideas. New tubes or what?