Why Tube Pre-SS amp over SS Pre- Tube amp?

I agree with Tvad. Much depends on the specific character of the components you're considering. Of all the combos I've tried, I'm happiest with my SS preamp driving a PX-25 tube amp. While the tube/SS pairing is touted as being more likely to be successful, nothing beats figuring out what your sonic preferences are and evaluating specific combinations from that point of view. Following a "generally applicable" approach isn't helpful if the particular combination you're evaluating doesn't float your boat.

Rlawry

Not an engineer so bear with me. But is that why the MOSEFT (sp?) design which amplifies voltage are supposed to sound similar to tubes.

I think plinius and belles use this circuit.

Tz&- Mosfet (sp correct) is a type of power transistor, not a circuit type.

The primary reason for going with tube pre into solid state amp is that it is much easier to get a lot of power from solid state than tube circuits. While I am not a fan of solid state amps of any power rating, I am also not a fan of most high powered tube amps as well. A lot of high powered tube amps sound hard and brittle and less natural than comparably powered solid state amps.

But, when feeding low-powered tube amps, the linestage issues become more mixed. I've heard a number of tube linestages that sound good in certain setups and quite bad in others; and the differences are often unpredictable. One really must try the specific pieces together. The solid state linestages I own and have tried in several systems (Placette Active and Levinson No. 32) seem more consistent and predictable than tube linestages I have heard.

But, when you find a good tube-into-tube arrangement, there really can be magic.

swamp,

thanks. does the fact that it changes voltage make it sound more like tubes that other SS options?