I used a Rogue Cronus Magnum with Harbeth SHL5+ and did not like the pairing at all. As a result of that experience, I swore off using Harbeth with tubes....until some Agon members encouraged me to give tubes another go.
I recently switched from a high powered solid state amp to an Air Tight ATM-2, which is based on the KT 88 tube like the VAC Sigma.
This is a tube amp that mates incredibly well with Harbeth.
