scotty_burford Posted September 23, 2013 Share Posted September 23, 2013 Guys I was setting up to do some studio work and the volume died after a minute or so. The valves have been making a few crackling noises and one no longer glowed so I just figured replacing that would be the thing. Swapped out the power amp valves. Both new ones glow nicely - but there is absolutely no sound at all. Swapped the fuse just in case there was an issue there (didn't seem to be but I did it anyway). Have tried different cables, speakers and speaker leads - still nothing. Any other ideas? I have a lot of studio work coming in the next fortnight as well as a few gigs and this is the only amp I currently own. Last time I checked the closest official repairman in Australia was 1000 km away - so can't send it there given y time restraints. Any advice would be greatly appreciated. Thanks Quote Link to comment Share on other sites More sharing options...
arislaf Posted September 23, 2013 Share Posted September 23, 2013 You did bias the new ones? Quote Link to comment Share on other sites More sharing options...
toneman2121 Posted September 23, 2013 Share Posted September 23, 2013 your amp may be one that is covered by bulletin 59. the transformer is the subject of that bulletin. call line6 and inquire about it. certain serial numbers are affected. Quote Link to comment Share on other sites More sharing options...
spaceatl Posted September 23, 2013 Share Posted September 23, 2013 I am not 100% certain as I have yet to open up my DT25 head, but the Spider Valves have a plate fuse located on the power amp PCB that requires pulling the chassis in order to change...heater fuse is also located similarly...These are in addition to the read panel protection fuse....My SV MK2 blew a power tube shortly after arriving in Atlanta from LA and it took the plate fuse with it....Anyway, the symptoms sound similar...amp fires up and the heaters glow, but no sound because the plates might not be firing up... 2 Quote Link to comment Share on other sites More sharing options...
stumblinman Posted September 23, 2013 Share Posted September 23, 2013 your amp may be one that is covered by bulletin 59. the transformer is the subject of that bulletin. call line6 and inquire about it. certain serial numbers are affected. That was on the DT50's if I recall correctly. Only a certain series of them before the DT25 was even released. 1 Quote Link to comment Share on other sites More sharing options...
TheRealZap Posted September 23, 2013 Share Posted September 23, 2013 that's probably right... but also his tubes still glow... means it isn't the same issue! That was on the DT50's if I recall correctly. Only a certain series of them before the DT25 was even released. 1 Quote Link to comment Share on other sites More sharing options...
stumblinman Posted September 23, 2013 Share Posted September 23, 2013 that's probably right... but also his tubes still glow... means it isn't the same issue! Yep, just trying to help eliminate erroneous answers so he's not steered down the wrong path. Especially if time is a factor. I say crack that puppy open! Quote Link to comment Share on other sites More sharing options...
scotty_burford Posted September 23, 2013 Author Share Posted September 23, 2013 Thanks guysArislaf - not yet. I swapped them over, tried it and was going to take it to a tech/friend's place today for him to check the bias for me. If the bias was out would that actually stop it from making a sound? I didn't think it would, but happy to be wrong in this. Quote Link to comment Share on other sites More sharing options...
spaceatl Posted September 24, 2013 Share Posted September 24, 2013 Bias being out of whack just might give you more xover distortion in class AB. Won't hurt anything but could compromise tone a bit. The bias adjustment has no meaning when the amp is running in class A. Did you look for an internal fuse? Quote Link to comment Share on other sites More sharing options...
shaker Posted September 25, 2013 Share Posted September 25, 2013 Whereabouts in Australia are you? Turramurra music in Sydney organised a line6 repair for me a little while ago. Last time I checked the closest official repairman in Australia was 1000 km away - so can't send it there given y time restraints. Any advice would be greatly appreciated. Thanks Quote Link to comment Share on other sites More sharing options...
toneman2121 Posted September 25, 2013 Share Posted September 25, 2013 try spacealt's suggestion Quote Link to comment Share on other sites More sharing options...
synaptictonality Posted October 1, 2013 Share Posted October 1, 2013 How old was your DT-25 before this happened and how much use/how hard did drive it daily? Quote Link to comment Share on other sites More sharing options...
stumblinman Posted October 3, 2013 Share Posted October 3, 2013 No reply from Scotty lately. Curious to see what his diagnosis was. Quote Link to comment Share on other sites More sharing options...
whiteop Posted October 9, 2013 Share Posted October 9, 2013 your amp may be one that is covered by bulletin 59. the transformer is the subject of that bulletin. call line6 and inquire about it. certain serial numbers are affected. I went through 3 DT-50 power transformer repairs before I got a "new" one which appears to have fixed the problem but that was only because a careless tech buggered the exterior of my amp. My casei is well documented on the forums. They are nice amps that sound really good live. Line 6 did treat me right that I cannot deny even though it was a real hassle to box up the amp and send it back each time. Call and ask for Ashley. Everyone knows her there. She is the definition of what customer service should look like. Good luck 1 Quote Link to comment Share on other sites More sharing options...
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.