Big, open, articulate; these are the words that came into my head when listening to the JJ 6L6GC tubes. The build quality is very rugged with thick glass and a well supported plate assembly. Perhaps this is a factor in the extremely low noise and lack of microphonics that this vacuum tube exhibits. The tubes have great tone and nicely capture the “6L6 sound”, characterized by sparkling highs, warm mids, and controlled bass response. Biasing was easy and well within the range of the standard bias adjustment circuit in the test amp. A great choice for any of the Fender amps made in the 60’s and 70’s.