My favorite are the same ones you like. The brown base, short bottle Sylvania 6SN7-WGT.
3 responses Add your response
The Sylvania brown base are very good. The RCA's are probably fairly cheap tubes--I recently replaced a pair with Brimar. Very big improvement. Have not been able to directly compare them with any of the Sylvania's. My guess would be the Brimars are a little more detailed and the Sylvania's a bit smoother.