Thanks, jl352. Incidentally, I was lucky to not have the preamp/speaker mismatch. I guess the three pairs of speakers I have used the amp with were not so efficient to create any (hiss/volume control) problems.
I did end up purchasing the simple little Schitt sys which I like experimenting with just for fun, but most of the time I have it set full volume so as to not impact my tube preamp signal going to the amp.
I did end up purchasing the simple little Schitt sys which I like experimenting with just for fun, but most of the time I have it set full volume so as to not impact my tube preamp signal going to the amp.