Yu11375, thanks for the comment on the S-30.
Onhwy61 is correct- most preamps have no output transformer. But with preamps the usual limitation at the output of the preamp is often the coupling cap, rather than an output transformer. Removing this part can result in a huge increase in detail/transparency and apparent speed without edginess or brightness.
Doing this is a but tricky; there are only a handful of ways to do it. Reliability is a factor- you don't want the preamp making DC voltages that could damage a power amplifier or speakers. We patented an elegant (IMO) method of doing this some years ago. Seems to me there are a few other tube preamps that also have direct-coupled outputs but this is quite rare! I think, other than the ones we make, you can count the others on one hand with fingers left over.
