Hi,
I used a Golden Tube SE40 with my 2/3s years ago w/ no problems, plenty of weight/dynamics in a relatively small room. I have also heard them with a number of other tube amps. Even with 6-8 W SETs they can sound decent, though I would prefer a little more power. The Spendors are rated at 88.5db for efficiency, but I think all Spendors have a pretty flat/high impedence load. The 2/3s should work well with most tube amps.
TLH
I used a Golden Tube SE40 with my 2/3s years ago w/ no problems, plenty of weight/dynamics in a relatively small room. I have also heard them with a number of other tube amps. Even with 6-8 W SETs they can sound decent, though I would prefer a little more power. The Spendors are rated at 88.5db for efficiency, but I think all Spendors have a pretty flat/high impedence load. The 2/3s should work well with most tube amps.
TLH