but dave don't you have a dt50.... that kinda sorta puts 4 tubes to your hd500 :-) i think you'll be ok....

but just in case i have a vox tonelab le i'll sell you :-)

Probably because VOX holds a US patent on the Valve Reactor...

Because there is not a one preamp tube circuit that would improve the product in any way shape or form. It would do nothing but add cost to the product. Only upside would be it would allow them to say "it haz toobz" in their marketing material.

Preamp modeling has been nailed by modern modelers and the non-power tube as a power amp with no real serious output transformer is more a liability than anything if you have decent digital algorithms for power amp modeling. They're better off in expending their R&D in that direction.

Sort of like saying, the Ford Mustang has racing stripes on it, Dodge should paint racing stripes on the Charger, too, it'd go even faster.