Falling out of love with tubes

I’ve owned an EICO ST-70 for eight years.  It’s modified and upgraded to the max, but with budget tubes. 

I just got got a Conrad Johnson SA-250 for a steal.  I plugged it in and it has blown my mind.  I feel like I’m hearing my music for the first time! So much detail I never noticed before!

I’m selling the EICO and will use the money for a preamp.   The SA-250 amp sounds kind of sterile/clinical to me.  Very unforgiving of a mediocre recording.

***Will using a preamp instead of going direct from my computer or tape sweeten the sound, even if it’s the solid state CJ Sc26 preamp?

***Will I lose the detail I hear if I get an older CJ tube pre in my price range? (Pv-10al) 

I’m listening to Silverline Prelude tower speakers, anticables level 2 speaker wires, anticables level 1 interconnects, and Denon dvd-2200 for CD, parasound zphono USB for my Supex SDX-1000  mc cartridge.  (Haven’t tried anything but phone, computer and cassette since I don’t have a preamp) 

Thanks in advance for your input.