Budget vacuum tube preamp?

I know that going with a tube preamp/linestage and solid state amplifier is an often recommended combination. But, you should at least address certain issues before going that route.

First, I have found the interaction of any particular tube linestage with a particular solid state amp to be more unpredictable than going all tube or all solid state. The idea of expecting a "warm" tube linestage to somehow balance a lean solid state amp, for example, often just does not work out. Also, a tube linestage that might be great with almost any tube amp is often more touchy when it comes to pairing with a solid state amp. In other words, an actual trial (or willingness to take a gamble) is a high priority when doing the mixing game.

Another thing that should be worked out are operational issues such as the powering up of gear. Solid state sounds better being left on all of the time, while tube gear should be turned off when not in use. If you chose a tube linestage that makes a lot of noise when first turned on, one may not be able to leave the amp on during such power up of the linestage if there is no ability to mute either component. The noise that some tube linestages put out when first turned on can damage speakers if the amp is powerful. Even if you plan to turn off the power amp when not in use, and always first power up the linestage before the amp, you need to consider the potential effect of an intermittent power outage and the power coming back on--the solid state amp will often come back on instantly, in which case it would be subjected to the noise of the linestage powering up. These things can be worked out (e.g., an automatic mute circuit on the linestage).

There is more to system matching than just deciding to drop in a tube pre with a ss amp. What constitutes a "budget" to you? What is the input impedance of the ss amp? What is the sensitivity of the ss amp? Other than HT bypass, what other inputs, tape loops, and phono stages, etc. might you need? Do you have the appropriate space for a tube pre to breathe? What are the sonic qualities of the rest of your system, and do you plan for the tube pre to compliment/compensate towards the final sound you are seeking?

Unsound, After reading your post I am thoroughly exhausted. There are so many things to think about. If I want to try a tube preamp in my system I just hook it up and see how it sounds. I did not realize there are so many technical things to consider.

At some time one does have to just hook it up and see how it sounds, but narrowing down the field IMHO ultimately is much less exhausting than needlessly and repeatedly buying and selling and reconfiguring.

I feel Unsound is right. Anyone doing their homework should consider what an impedance mismatch between the amp and preamp will do to the sound. Start with the output impedance of the preamp and the input impedance of the amp. Even beneficial specs guarantee nothing regarding SQ, but gives you a shorter list of preamps to try and preamps to eliminate from consideration.