Preamps for $300 to match with B&K st-140?

Look for used Forte preamp. I know the Model 2 will work very nicely.

Happy hunting.

I am useing a Parasound 850 with my B&K ST-140 right now in my den system and it sounds good. The Parasound has a phono section also and they can be found for cheap used

Im looking at a nice Nakamichi ca-5a2, any opinions?

Unsound, i dont know that i follow your reasoning on the Audible Illusions paired with the ST 140. The B&K has an input impedance of 24.3 kohms and the audible illusions has an output impedance of 600ohms(AI tubes run in parallel thus having their impedance). That is well with in the 10-100 times guidline. Also the AI has plenty of gain to allow for nice volume control for such a low input amp. Also since the ST 140 sits on the warm side of nuetral the AI might be just what the doctor ordered.

Kool39, "the 10-100 times guideline" is some what arbitrary and IMHO generous. While 600 Ohms will probably work, it might require more attention to interconnect selection.