|
Title: 1/2 power switch Post by: richlespaul on December 30, 2007, 03:36:51 AM I´d like to fit a 1/2 (or what ever it works out at?) power switch to m JTM45. Can it be done and is it an easy mod? :)
Title: Re: 1/2 power switch Post by: Roe on December 30, 2007, 07:47:42 PM I wouldnt do it. won't help much (2db) and wont sound as good as full power
Title: Re: 1/2 power switch Post by: skydog79 on January 05, 2008, 09:11:34 PM what about 6v6 power tubes? anyone try that? I'd like to. Is there a mod necessary? I also read somewere you may have to use different recto: gz34 to 5y3
Title: Re: 1/2 power switch Post by: Roe on January 07, 2008, 03:33:41 PM jj 6v6s will work. but adjust the bias. you might have to change the bias resistor
Title: Re: 1/2 power switch Post by: skydog79 on January 08, 2008, 08:42:15 AM might? how will I know if I need to or not? and what do I change it to if I do need to? and is it true that you have to use a different rectifier tube?
Title: Re: 1/2 power switch Post by: Roe on January 09, 2008, 08:14:14 AM just try to adjust the bias pot. if you don't have enough range with the 6v6s, then you need to change the resistor. this is the 56k resistor connected to the 22k pot on the left.
greg germino seems to recommend a 5Y3 or 5U4 rectifer if you run 6v6s in a jtm45 Title: Re: 1/2 power switch Post by: skydog79 on January 09, 2008, 11:49:38 AM I've been checkin' out reviews on the jj 6v6 and they seem to be loved but a lot of guys say its verry simillar to jj 6L6. jj6v6 are rated to handle 500v to so I could get away with keepin' the 5ar4/gz34 but I might not get as early breakup as I'm hopeing for. It's funny you mention Greg Germino, thats why I want to try the 6v6 in my jtm45. He use to make an amp called the Masonette 25 that ran 6v6 and sounded awsome. Anyway, I think I'm gonna try out Tung Sol 6v6 and change the rectifier to 5y3 like Greg recomends. (maybe I'll try jj first, I'm not sure)
|