Just to chime in a bit.....See if this link works to the Yahoo! group for Golden Tube Audio equipment.
http://tech.groups.yahoo.com/group/golden_tube/
I have owned an SE-100 (1-6SL7GT, 2-EL34 (driver), 8-EL34 (output)) for over 12 years with just one initial issue. A capacitor went in the small input circuit board that the 6SL7GT is also mounted. GTA replaced it.....no issues since.
Yes, if an issue arises, there are many guys out there that repair these.
Very, very nice sounding amp......a little warmer than VTL 100 mono's. Absolutely beats the heck out of the Aragon 4004 Mk II I had before it (made it sound two-dimensional, grainy and much less life-like by comparison, and the 200w solid state amp didn't even produce better dynamics or bass to trade).
My only issue with the amp is the gold anodized front.....doesn't match anything else I have. Can this be changed? I love the look of the Cary V-12's.....and the GTA has me convinced that I like the 8 x EL34's. If anything happens to the GTA, I'd like to try the Cary.
The Golden Tube has been a great match for my Alon II's and ProAc Studio 200's. Both speakers, I believe that may prefer tube amps.