Solid state amp/Tube Preamp. Possible?

You want to look at the highest output impedance measurement of a preamp, not just the nominal output impedance spec. Output impedances rise substantially, especially in the lower frequencies. Matching a preamp with a high output impedance in the low frequencies with a low input impedance amplifier (typical of many solid state amps) will result in rolled of bass.

Stereophile's measurements of the BAT VK-3iX states:

"The VK-3iX's output impedance was also high, and this might well have an effect on sound quality, depending on the input impedance of the partnering amplifier. The unbalanced source impedance varied from 7k ohms at 20Hz to 1460 ohms at 1kHz and 2650 ohms at 20kHz, while the balanced figures ranged from a very high 14k ohms at 20Hz to 1850 ohms in the midband and above."

BAT's amps have an input impedance of 100k ohms. Check the specs on your amp. All I could find was an input impedance spec for the CA 200, which is 75k ohms. If this applies for the CA 300, then it's likely you can get away with the BAT preamp. Generally, BAT preamps are not a good match for many solid state amps that have low input impedances for the reason mentioned above.

I have actually had the Classe 400 with the BAT VK-3i and the match was excellent driving my older Mirage M3 speakers. I had the Odyssey Stratos with that system as well, and the sound was also excellent. The CDP was a Meridian, warmest most musical system I probably have had in 1 room.
I think your going in the right direction.

Z

My first tubed component was a preamp matched to a solid state amp and it was not a problem. Matching the impedance as listed in some other posts is usually not a problem either. I also think that if you are going to move towards tubes, you are headed in the right direction and will probably get more pleasing results with the tubed preamp rather than if you had a tube power amp with a solid state preamp. Just my opinion!!

12-02-08: Cyclonicman
Matching the impedance as listed in some other posts is usually not a
problem either.

John Atkinson provides reasons in his Stereophile test measurements section for
the potential impedance mismatches. Perhaps I have not presented the reasons
clearly, but the issue exists nonetheless.

Readers should look at Atkinson's measurements sections in Stereophile
reviews for further information. He has tested several BAT preamps.

As I stated earlier, the BAT/Classe match will likely be good based on the
numbers, but to say matching impedance is usually not a problem is simply
incorrect.

Perhaps, I'm misunderstanding Cyclonicman's point.

I use a Supratek Chenin with a Gilmore Class D amp and the combo sounds sensational. No impedance problems there. The output impedance of the Supratek is ~200ohms, so it matches up well with just about any amp.