scotty is correct re: impedance. generally, s/s preamps don't have this issue; tube pre's can have higher impedances that might create a problem. normal rule of thumb is that your pre's output impedance should be at least 10 times lower than the input impedance of your amp(s). if you connect two amps rated 50kohm input impedance to a pre, the pre sees a 25kohm load...
doug s.