you won't have a problem with impedences using a ss pre amp. you want the pre-amp output impedence to be no greater than 1/10th of the imput impedence of the amp. most ss preamps have output impedences of l ohm or less (whereas tube preamps typically have high output impedences anywhere from 500 to 3500 ohm, more or less, which require high imput impedence in the amp. tube amps typically have high impedences and will match well with eith ss or tube preamps. the same cannot be said for matching tube preamps with ss amps - thats where the trouble can be. Relax about the electrical match. However it would seem to me, sonically speaking, that you would have a much better realization of the benefits of a tube amp by using a tube preamp to go with it.
