Reproduction of acoustic instruments with tube amp

I would certainly aim for used BAT VK60 the regular stereo version. I believe that no better one can be offered to you in that price range if you are OK with used.

Dburdick, i don't know if the ST 85 can operate in Triode mode but i'm using VTL 185 monos with the 5.5 sig preamp and in triode small scale acoustic music is pretty much like being in the room with the musicians. seperation and definition is not a problem. in my comparisons with ss and tubes the ss amps won't touch the tubes for midrange wich is where the acoustic instruments dominate My guess is the VTL you were using didn't have enough juice to handle your speakers.

I agree with Marakanetz. A used BAT VK60 on this site should be in your price range. Most of the music I listen to is chamber music or acoustic guitar, and they both sound great with the VK60. I don't think you can go wrong.

I too find Dburdick's findings surprising. The VTL ST-85 should be able to drive the Sparks no problem. I haven't heard the combo myself, but when I recently auditioned the new Thiel 1.6's with both my own c-j MV-55 and the store's VTL ST-85, I thought the latter was outstanding for acoustic (and electric) music, with a vast soundstage and very 3-D imaging. It did strike me as possibly a touch overripe through the midrange, but not excessively colored for enjoyment, and still quite transparent for the money. In that system (with Transparent wire), it frankly made my c-j sound small and pinched. Fortunately, the MV-55 sounds better at my place (Thiel 2.2's, Cardas Cross) - full, spacious, and neutral (and it far outshines my previous SS amps, especially with acoustic material). If in Dburdick's system the VTL didn't offer separation and definition with acoustic music, I would suspect a wire mis-match and/or poor tubes as possible culprits.

It sounds like I just haven't heard a really good tube amp. I also suspected bad tubes in the VTL (bought used) but didn't want to spend the time/money to find out. I have had similar experience with other tube amps though as well so I guess I just gave up. I guess I'll have to give it another shot and look for a CJ or BAT here on A-gon. Thanks again for the friendly advice. I'll have to do some research to learn a little about tubes and the characteristic sound of each!