I would try the Schitt Freya+ ($1000) with the 4B3 if I wanted a warmer sound. Or someone other tube preamp. I know that a BAT VK-42SE that I had in the past worked well with Bryston 7B-SST. Though the cube line is warmer than the SST line. I currently use the Freya+ with a Benchmark AHB2 amp that is very neutral, and it is an excellent combo.
If you do not need the extra warmth and want a preamp that adds nothing to the sound, I would get a Benchmark LA4 ($2600). In a few months I will sell my Freya+ to get a second LA4 or HPA4.
Will try covering tv with a quilt during listening sessions but if that doesnt work it has to go.
I started a thread about covering up my TV with sound absorption cloth or panels. I did a lot of research and bought a good panel. However, the sound still was worse than having no TV in the middle, so I got rid of the TV. I use the panel now to cover my CD rack which is a nice improvement.