Along with the team at the Golden Tube group at on Yahoo, I've assembled a comprehensive service manual for maintaining the Golden Tube Audio SE-40 power amp.
The service manual covers tube swaps, proper biasing, and troubling shooting. The directions contained in various Audiogon threads are WRONG. This manual has the CORRECT procedure.
http://groups.yahoo.com/neo/groups/golden_tube/infoHope this is helpful.
-David