Running the output of a tube component into the input of a solid state component makes it particularly important to consider impedance relationships. I seem to recall reading that Keith recommends against loading the output of the VTPH-2 with relatively low input impedances, although I don't recall the specific number that was mentioned.
I suspect that the Simaudio P-7, at 22K, would be marginal. The balanced inputs of the Ayre components that Zd suggested, which you would not be using to connect to the Herron's single-ended outputs, are spec'd at 20K per phase for the K-5xe and 10K per phase for the K-1xe. That suggests the possibility that those numbers may also be the unspecified input impedances of the unbalanced inputs, which I suspect would be too low to be a good match.
Good luck in your search. Regards,
-- Al
I suspect that the Simaudio P-7, at 22K, would be marginal. The balanced inputs of the Ayre components that Zd suggested, which you would not be using to connect to the Herron's single-ended outputs, are spec'd at 20K per phase for the K-5xe and 10K per phase for the K-1xe. That suggests the possibility that those numbers may also be the unspecified input impedances of the unbalanced inputs, which I suspect would be too low to be a good match.
Good luck in your search. Regards,
-- Al