Hello Tube Amplification--Goodbye Subwoofer

Congratulations on your acquisition.

I certainly enjoy my HP.  You may be surprised how  keeping your sub,and adjusting it to the lowest registers your main speakers can't produce ,add presence and pressurize the room. I won't go without a sub, even though my speakers are spec'ed down to 30hz.

Now you you can obsess over  which power tube your ears prefer along with fine tuning with the 2 innermost preamp tubes. Stock set is fine, but after the novelty wears off, audio nervosa may set in.

jbhiller-

A factor to consider is leaving your gear alone and pay attention to speaker/sub placement and room setup. Especially if your system is in a multipurpose room. The coffee table in front of your listening area, the windows on the side wall next to your speakers, etc. All
the everyday things in our rooms are affecting the sound if you don't have a dedicated room.

My REL B3 location is best equal distance behind the listening sofa on a side wall. Unconventional, but the most natural sounding position, as the sub pressurizes and fills the entire room with sub 30hz frequency, not just the immediate front listening space. No
hint of a sub in the room, just realistic bottom end tone that average floorstanders can't produce. 

I also have found AC regen feeding everything(including the HP) in my system a game changer along with power cords.YMMV, as everything else audio.

Play it LOUD