Difference between a Classe DR-3 VHC & DR-3B

I easily drove Apogee Duetta ribbon speakers with a DR3 for years so I'm not sure you NEED a VHC. Both amps are a pure class A design; the VHC is quite a bit bigger physically and certainly delivers mucho current. Unless you're driving a 1 ohm load (like the Apogee Scintillas) the DR-3 ought to be plenty.

as i recall there is a substantial difference in the current that the VHC will deliver, but i don't know the exact amount. the VHC is substantially larger amp (taller).