I believe I'll need to change the final tubes in my old faithful SB-401 - output has dropped to about 60W - which 6146 (A, B, W ?) should I get. Are matched pairs necessary? Thanks. -------------- next part -------------- An HTML attachment was scrubbed... URL: <https://puck.nether.net/pipermail/heath/attachments/19980506/8b267a92/attachment.html>