If you had to choose: tube amp or tube pre-amp?

I think I would go with a tube Pre-Amplifier first.

I say this because of the way Tube Hybrid Amps are made with the Pre section being tube and the amplifier section being Solid State.

I do not think i have seen it the other way around.

Your speakers would be helpful. If you are set on your speakers I would get a power amp first and then later a preamp If you tell us what your speakers are you will get recommendations for related amplification
Alan

It depends on your speaker. If your speaker is compatible with tubes I`d go tube power amplifier if your goal is tube sonic attributes. The tube preamp won`t have the same influence and the SS amp presence will be known(ok if that`s what you want).
Regards,

Impossible to say without knowing what speakers are being used. Depending mainly on how their impedance varies as a function of frequency, some speakers will not sound right with one type of amp or the other.

It is also impossible to say without knowing whether the B&K amp or the preamp section of the Sony a/v receiver you are using is a greater limitation on the sound quality you are presently achieving. Not being familiar with either model, I can't address that question. And the answer may depend on the impedance characteristics of the speakers, and how difficult they are to drive.

As a general philosophical matter, though, if the speakers can work well with a tube amp I agree with the comments by Michael and Charles, and my vote would be tube amp, ss preamp. If you research past threads on this question, however, you will find that opinion is divided, and there is no consensus.

Regards,
-- Al

Tube Amp first. Tube Pre second. Tubes ATW.