I use my 17 year old BAT VK-60 to power my Von Schweikert VR-5 Anniversaries. I don't even use a preamp. Tube amps typically love Von Schweikert speakers. I was contemplating selling the VK-60 (which still has all its original power tubes) until I recently replaced the four original Jensen caps with Dueland CAST copper caps. The Dueland caps transformed the sound of the VK-60 into something wonderful. The sound stage, the clarity, the frequency range, the realism -- all there, bringing out the best of the VS speakers. The VK-60 with the Dueland caps now sounds better to me than my $15K PassLabs monoblocks. If you have a VK-60 and love it, you'll love it even more with Dueland CAST caps. I changed the caps myself and I'm not a technician. I ordered them from HiFiCollective in England.
