"Just Listen"...to you! "Love the sound", "Don’t feel you have to turn it up much", "20+ years on the tubes"," Listen to jazz and some pop". First, it does not surprise me one bit that you need to replace the tubes....way late! But, since you never felt the need to turn it up much, maybe it wasn’t overdriven and therefore need to have (all/though probably some) of the caps and resistors replaced. Most of the time, problems with tube amps are the tubes. Try that first.-Your least expensive option.
Keep your speakers if you like them. Use 4 ohm taps on your amp (maybe, always listen), but tubes generally do like 8 ohms better. Have fun listening to more modern 8 ohm speakers at shows in the meantime or try buying used well-reviewed 8 ohm ,more efficient speakers here on Audiogon. Speaker design has improved in 20 years!
Moving up the power tube chain will likely lose some of the "aire" and Magic that I think you’ve become used to with the 300B’s. However.....
Parting thought: You might try a Croft Series 7RS Hybrid amplifier if you get a chance.
Keep your speakers if you like them. Use 4 ohm taps on your amp (maybe, always listen), but tubes generally do like 8 ohms better. Have fun listening to more modern 8 ohm speakers at shows in the meantime or try buying used well-reviewed 8 ohm ,more efficient speakers here on Audiogon. Speaker design has improved in 20 years!
Moving up the power tube chain will likely lose some of the "aire" and Magic that I think you’ve become used to with the 300B’s. However.....
Parting thought: You might try a Croft Series 7RS Hybrid amplifier if you get a chance.