Seeking a Tube preamplifier

I currently have the following system:

• 1. Martin Logan 11A Impression Loudspeakers (hybrid electrostatic)
• 2. Bryston 4B3 Cubed power amplifier 300 into 8 and 500 into 4
• 3. Bryston Bp-19 preamp recently purchased
• 4. Rogue Audio RP-1 tubed preamp backup for BP-19 preamp
• 5. Weiss Dac 204 with Modwright Linear Power Supply
• 6. Lumin U2 mini streamer with S Booster linear power supply
• 7. SVS Pair of SB-4000 subs.

I like the Bp-19 preamp. The sound is refined, detailed and clear but it is missing  some of what a tubed preamp delivers. I switched to my backup preamp which is a tubed Rogue Audio RP-1 entry level and noticed that is wasn't as resolving or crystal clear as the Bryston BP-19, but I noticed that a vocalist  projected air, depth  and a richness that I did not find on my solid state preamp. On a track with a guitar there was a bloom and decay that I didn't notice on the solid state. Now I was thinking what about a tubed preamp that delivers both the positives of a solid state and tubed preamp?  My maximum budget new only is $7500.00. Only need a linestage as phono is not required. In any case, I started looking at the entry level Conrad Johnson ET6SE, but confirmed with manufacturer this morning that there is no way to control the balance on their entry level product. I am disappointed, but my seating requires the ability to control the balance. I was also looking at the Rogue Audio RP-9, but their product uses a 6H30 tube which may be difficult to obtain in the future. Any suggestions or thoughts would be appreciated.  Thank you.