I probably have 50 or so 6550s or KT88s. Unless you want the NOS Tung Sol 6550s which are pricy, the Genelex Gold Lions are a pretty good choice. I've had the 275s and have been running MC60s for the last few years. The reissue Tung Sols have really good "shove" but are just slightly grainy. Sophia Electric very resolving but the bass isn't quite there. Good tubes though.
I do have a matched quad of NOS Tung Sol 6550s three hole grey plate which have never been unpackaged. I've never sold anything on Agon but would list them if you're interested. The bass, while not light, is just a bit tubey. Voices and instruments are by a good measure more real. Got them from Tube Depot I believe.
If you want the ultimate tube I just saw some NOS Black Plate Tung Sol on Tube Depot, the tube the original 275s were voiced with. $650 each (whew). But they are the best ever made, or so I've heard. If you are keeping the 275s for the long haul these may be of more value to you than may be apparent. Like the grey plates, but supposedly the bass is the best of all. I've been watching for 5 years and these are the first NOS Black Plates I've seen.
I do have a matched quad of NOS Tung Sol 6550s three hole grey plate which have never been unpackaged. I've never sold anything on Agon but would list them if you're interested. The bass, while not light, is just a bit tubey. Voices and instruments are by a good measure more real. Got them from Tube Depot I believe.
If you want the ultimate tube I just saw some NOS Black Plate Tung Sol on Tube Depot, the tube the original 275s were voiced with. $650 each (whew). But they are the best ever made, or so I've heard. If you are keeping the 275s for the long haul these may be of more value to you than may be apparent. Like the grey plates, but supposedly the bass is the best of all. I've been watching for 5 years and these are the first NOS Black Plates I've seen.