guitbanger
Active Member
Tube manual say's 45 wt fixed bias @ 1.5 o/o thd.
That sounds unrealistic to me. 20 wpc in cathode bias might be a little optimisitc from a 7591, but 35 from the same thing but with fixed bias sounds like a pie in the sky number. I think my Sherwood is rated at 48 watts, or 24 WPC with it's fixed bias configuration and 7591 tubes.
That's just about all the caps, but I'm having trouble with a couple of them. The big red cap underneath is a 30uf 400v. These seem really expensive, like $15. Is that about right or am I looking at the wrong thing? Even 2 15uf will be over $10. Also, the "death cap" is a .03uf 600v. I can't find anything to match that. Though I may go to a standard power cord and won't need it if I do that.
I might suggest Jim McShane for the EH tubes. He screens and matches them a little more carefully than most and I don't believe his prices are much different than anyone else's.
Good luck with the rebuild!
The tube rectifier doesn't work until it gets near normal voltage, and then... Boom. Bye bye caps.
Use a large resistor before the first cap. This limits current, and lets even the most stubborn cap reform over MANY hours.. Without guess work. Won't save 'em all.. but you can watch them reform on your meter(go across the resistor). You'll be pleasantly surprised how many you can bring back from the grave, that otherwise would have died using a variac with a tube rectifier.
Have fun in there.