But since tubes are en vogue again there is a lot of junk out there on the market.
The influence of the power supply is much higher with tube gear than with ss-based (pre-)amps.
An improved ps will do magic if you know where to install/change capacitors either in the output stage or in the ps.
My AR pre now shows all the virtues of a modern construction, but still with the magic only tubes can do- decay, resolution, soundstage, imaging.
I will definitely not go back to transistorized preamps.