Well, I went down to the Fifth Avenue Fretshop (in Columbus, Ohio) yesterday to hang with my good buddy (and
BGM Technical Editor) Phil Maneri. I wanted Phil to look at one of my basses, and as long as I was coming down, he asked if I could bring along some all-tube heads for him to check out. Of course, I had to bring my Sadowsky SA200.
We spent most of the time playing Phil's vintage ('63, I think) Precision, and the cabs were two EA VL-208's (Phil's personal cabs), and we were all surprised how great they sounded with these tube heads! What was even more unexpected (and even more impressive!) was how good the SA200 sounded with Phil's old European upright! According to Phil, it was quite possibly the best his bass had sounded, and we had zero feedback issues, even without using a high pass filter.

Very impressive.
Here are the videos for the SA200:
SA200 with Precision Bass
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