Tube life

Greetings,

Wondering if my tubes or my hearing’s going. Feeling my system should sound better. Bought  Vandersteen Quatros 2 months ago and believe I've got them dialed in fairly well. I include this because I don't have years of listening to them to compare back to. Have to turn my CJ Premier 16 pre to about 43 to get a decent amount of sound. These Quatros replaced Tannoy Kensingtons that only needed a volume setting of 32 for a decent amount of sound.

System is:  

• Pre:   Conrad Johnson Premier 16LS
• Pwr:   Conrad Johnson Premier 12 Mono Blocks
• Pwr Condtnr: Shunyata Hydra
• Speakers: Vandersteen Quatros
• Cabeling: Stealth PGS IC’s, Vandenhull Bi-wire Speaker wiring
• Sources: Conrad Johnson DV-2B CD Player, SOTA Star w/SME arm w/Benz cart, Magnum Dynalab Tube Tun
• Music:   Classic Rock, Easy listening, Female Jazz singers, Classical
• Room:   Big (25 X 30) w/cathedral ceiling. Harwood floors/ceiling and big glass windows. Rugs and furniture

Replaced all unit's tubes 5 years ago and bought them all from Conrad Johnson. Play the system about 10 hours a week so that would be about 2600 hours of play.

Think the tubes have seen their better days? My hearing? I'm 56...

Thank you!