Andy Blowers Posted November 1, 2012 Share Posted November 1, 2012 Has anyone replaced the output valves? I swapped mine out for a set of JJ EL84's from HotRox and when I fire it up the valve nearest the mains transformer seems to get a lot of juice first, it glows really bright, then calms down to normal, then the rest of the valves seem to get juice... Any ideas? Quote Link to comment Share on other sites More sharing options...
The fasting showman Posted November 1, 2012 Share Posted November 1, 2012 I've known valve socket / valve pin tension issues to cause this problem, I had it happen with 2 jj 6l6s I had in push / pull. The amp tech I use tensioned the socket and it cured the problem. Lots of nasty high voltages so one for a tech only. I'd guess the problem is with the socket of the EL84 that doesn't glow bright, if that makes sense. It may not be that but worth checking. Quote Link to comment Share on other sites More sharing options...
Andy Blowers Posted November 1, 2012 Share Posted November 1, 2012 (edited) Thanks. I'll try re-seating the valve to make sure it is in properly, failing that, I'll give it to my mate/tech. The bugger seems to get a huge hit of power, then the others come on. Kind of like squeezing the hose pipe, getting it to ballon and then releasing it. Interestingly, it only started to occur after I put it back into the head "box". Edited November 1, 2012 by Andy Blowers Quote Link to comment Share on other sites More sharing options...
The fasting showman Posted November 1, 2012 Share Posted November 1, 2012 I know that a notorious re-badger of JJ valves has stated that there can be issues with pin sizes on JJ valves causing socket seating problems. I don't know whether that's true or not, and it wouldn't put me off JJs, but it was an issue in the Bassman I revalved. Hope it's something nice and easy like that anyway, good luck! Quote Link to comment Share on other sites More sharing options...
Andy Blowers Posted November 1, 2012 Share Posted November 1, 2012 I'll pop it into the position nearest the output tranny and see what happens there... If it still happens, it may have dodgy pins or something. Quote Link to comment Share on other sites More sharing options...
RandomBass Posted November 2, 2012 Share Posted November 2, 2012 I put some JJ output valves in my LB30 no prob. Slightly tighter bottom end, but don't like the highs so much for some reason. All very marginal though. Quote Link to comment Share on other sites More sharing options...
Andy Blowers Posted November 3, 2012 Share Posted November 3, 2012 Wasn't seated properly. D'oh. Quote Link to comment Share on other sites More sharing options...
dan670844 Posted November 3, 2012 Share Posted November 3, 2012 [quote name='RandomBass' timestamp='1351847284' post='1856042'] I put some JJ output valves in my LB30 no prob. Slightly tighter bottom end, but don't like the highs so much for some reason. All very marginal though. [/quote] I agree, I think it depends with version you have, the jj 's sound best in the uk version, the chinese version sounds best with shungangs either from tad, groove tubes or ruby tubes, i tried jjs in the chinese one and they were far to bassy , it has enough bottom already, puts all those digi amps to shame, except the streamliner and mibass! they also roll of the high to much! Quote Link to comment Share on other sites More sharing options...
Andy Blowers Posted November 4, 2012 Share Posted November 4, 2012 I popped the JJ's in as I got them from Hotrox as they offered them with a hot current draw to stay cleaner, as I wanted a bit more clean out of it, and it does give me the clean. Now I just need to get the preamp to clean up a bit more now... Quote Link to comment Share on other sites More sharing options...
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