After 17 years of playing exclusively clean SS heads and now looking for a bit of re-juvenation + new options, I am looking into tube amps. Had a Peavey VB-2 home to try it out and was not overly impressed. The iconic SVT seems more attractive but I know that there will be times when I need more clean output than it provides. How do these amps (mainly the CL or Heritage) behave when hooked up to an external SS PA amp? Are there issues with signal level, ground hum, noise floor, impedance etc?