Tube in Preamp or Power amp?

Just starting out with tubed components the preamp is easier to deal with.They do have a highish output impedance so make sure your amp's input impedance is a higher value than the pre's output.IMO tubed components allow the music to become more natural and alive.Good luck in your search!

I doubt you will get a definitive answer to your question, but you do need to maintain system synergy.

For a tube amp, the speaker's impedance curve should not have substantial dips below the nominal impedance.

For a tube preamp, proper impedance matching to the SS amp must be observed.

If you are going to try a tube component, just make sure it will work properly with the rest of your system.

They do have a highish output impedance so make sure your amp's input impedance is a higher value than the pre's output.

Just being higher is too vague, as it should be at least 10 times higher at all frequencies.

+1 Jtcf and Tls49

What speakers would you be driving?