Members alteredsounds Posted July 11, 2006 Members Share Posted July 11, 2006 Playing last night and the volume on the DSL100 suddenly drops to about half, few seconds later it goes back to normal but just after that the amp dies, no lights or anything. Checked the fuses, HT Fuse is ok but Mains Fuse is blown. Looked in the amp and 1 powertube (EL34) is semi-melted on 1 side and has loads of cracks. Am I right in thinking that the valve just blew and in doing so popped the mains fuse? Shouldnt it have taked the HT fuse too? Got a band practice tommorrow night and my 5150 is about 200 miles away! (please please please not the output transformer!) Link to comment Share on other sites More sharing options...
Members alteredsounds Posted July 11, 2006 Author Members Share Posted July 11, 2006 sorry to bump so quick but i'm stuck Link to comment Share on other sites More sharing options...
Members BandofThievesâ„¢ Posted July 11, 2006 Members Share Posted July 11, 2006 Unplug your amp.Pull all the tubes.Replace the fuse and turn the amp on.If it blows the fuse again you need to take it to a shop. If it doesn't blow,shut her down and replace your tubes one at a time.(Don't use that old tube)Turn the amp on.If the fuse blows as you replace each tube(one at a time) then you have a tube problem..Chances are someone dropped your amp or the power tube just gave up..I hope so.Good luckand have someone qualified check your amp if you don't know what you are doing.That amp can AND WILL HURT you..Keith Link to comment Share on other sites More sharing options...
Members alteredsounds Posted July 11, 2006 Author Members Share Posted July 11, 2006 cheers for the reply mate. I was going to pull the tubes and try it without but didnt know if it'd hurt the amp having no output tubes in? amp hasnt been dropped but the tubes have never been changed and I dont know how much it was used before i had it. Link to comment Share on other sites More sharing options...
Members edster Posted July 11, 2006 Members Share Posted July 11, 2006 More than likely a tube problem. The broken tube probably broke while you were playing, which is when the power dropped. After it filled w/air it would have started arcing and that's when the fuse blew. Try what BOT suggested to start. You might want to use a slightly smaller fuse just in case there is a problem. Link to comment Share on other sites More sharing options...
Members BandofThievesâ„¢ Posted July 11, 2006 Members Share Posted July 11, 2006 You can do a yahoo search for Tube amp troubleshooting for more details..Good luck,KeithPS Go ahead and use the same type and size fuse... Link to comment Share on other sites More sharing options...
Members alteredsounds Posted July 11, 2006 Author Members Share Posted July 11, 2006 Much appreciated guys. Had tubes go before but never partly melt! Link to comment Share on other sites More sharing options...
Members BandofThievesâ„¢ Posted July 11, 2006 Members Share Posted July 11, 2006 Originally posted by alteredsounds Much appreciated guys. Had tubes go before but never partly melt! I am off to work now..Keep us posted, Keith Be Careful... Link to comment Share on other sites More sharing options...
Members edster Posted July 11, 2006 Members Share Posted July 11, 2006 When trouble-shooting a failed tube amp, it is a really good idea to use a smaller fuse. If there is a short in your amp other than the tube, additional damage can be done if you power it up w/a new fuse. You want the smallest fuse that will turn your amp on w/out blowing. Usually 50% or so. In your case, IIRC you have a 2 amp mains fuse, so you would use a 1 amp fuse for testing. This may be totally unnecessary in your case but, it's better to err on the side of caution here. Especially if your unsure of yourself. Not sure why BOT felt the need to dismiss this. It is a widely used technique among techs and one I use often. Link to comment Share on other sites More sharing options...
Members BandofThievesâ„¢ Posted July 11, 2006 Members Share Posted July 11, 2006 Originally posted by edster When trouble-shooting a failed tube amp, it is a really good idea to use a smaller fuse. If there is a short in your amp other than the tube, additional damage can be done if you power it up w/a new fuse. You want the smallest fuse that will turn your amp on w/out blowing. Usually 50% or so. In your case, IIRC you have a 2 amp mains fuse, so you would use a 1 amp fuse for testing. This may be totally unnecessary in your case but, it's better to err on the side of caution here. Especially if your unsure of yourself. Not sure why BOT felt the need to dismiss this. It is a widely used technique among techs and one I use often. You are absolutely correct Sir.A smaller fuse is safer.I do that when working on a customers amp.I meant it was ok to use the same value and type fuse..I kind of think his problem is simply a tube..I hope so for his sake..Sorry for the misunderstanding.. Link to comment Share on other sites More sharing options...
Members st. fermin Posted July 11, 2006 Members Share Posted July 11, 2006 I have had some rediuculous thigns happen to my tube amps over the years and had them work just fine after a retubing. Had a pair of 6550s arc and melt the glass pretty good, had a number of 6V6s arc nearly white hot inside before going kaput, had various tubes do that 'plasma ball' thing where it looked like lightning inside the glass, also had an EL34 go POP real loud just recently. That one broke the bottle in a pretty cool pattern all the way around - the glass just slid right off when I took the tube out. Nifty. So what I am saying is, yeah there could be some bad stuff going in internally, but tube amps are very robust by their very nature, so the odds are in favor of your amp being perfectly fine. Hope it all works out for you on the cheap! Link to comment Share on other sites More sharing options...
Members edster Posted July 11, 2006 Members Share Posted July 11, 2006 Ok....my misunderstanding. Link to comment Share on other sites More sharing options...
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