smurph1 Posted March 23, 2011 Posted March 23, 2011 So I pulled the tube cage off the back of my Classic 30..turned it back on, and the hum WAS A HUNDRED TIMES WORSE!!Then i tried switching tubes around making sure they were seated correctly..Still massive hum..I guess the next thing is to put the tube cage back on and see what happens.. Should I just replace all the tubes? Is it possible they all went bad at once? Or is it something else? HELP!!
DetroitBlues Posted March 23, 2011 Posted March 23, 2011 So I pulled the tube cage off the back of my Classic 30..turned it back on, and the hum WAS A HUNDRED TIMES WORSE!!Then i tried switching tubes around making sure they were seated correctly..Still massive hum..I guess the next thing is to put the tube cage back on and see what happens.. Should I just replace all the tubes? Is it possible they all went bad at once? Or is it something else? HELP!! The power tubes work together, so I suggest retubing the amp. Just by shaking it enought to rattle it, you may have made it worse. If you can find a little mom and pop shop guitar store, you should be able to find some decent used ones. If not, let me know what tubes you need, the place down the street sells all used tubes for $5 a piece....
kbp810 Posted March 23, 2011 Posted March 23, 2011 So I pulled the tube cage off the back of my Classic 30..turned it back on, and the hum WAS A HUNDRED TIMES WORSE!!Then i tried switching tubes around making sure they were seated correctly..Still massive hum..I guess the next thing is to put the tube cage back on and see what happens.. Should I just replace all the tubes? Is it possible they all went bad at once? Or is it something else? HELP!! So the hum got that much worse just by taking the cage off? Yikes! Do you by chance have another known good preamp tube available? Might want to swap one by one to see if it gets better (before going all in with a full swap)
smurph1 Posted March 23, 2011 Author Posted March 23, 2011 So the hum got that much worse just by taking the cage off? Yikes! Do you by chance have another known good preamp tube available? Might want to swap one by one to see if it gets better (before going all in with a full swap) I've got 4 small tubes and 3 big ones..Are the small ones the pre-amp tubes?..If so, I do have a brand new pre amp tube..
DetroitBlues Posted March 23, 2011 Posted March 23, 2011 I've got 4 small tubes and 3 big ones..Are the small ones the pre-amp tubes?..If so, I do have a brand new pre amp tube.. Yep, those are preamp tubes. Usually those last a long, long time....
smurph1 Posted March 23, 2011 Author Posted March 23, 2011 Yep, those are preamp tubes. Usually those last a long, long time.... So..chances are the noise is coming from a Power Tube, right? sorry I'm kind of ignorant of this technical stuff..
DetroitBlues Posted March 23, 2011 Posted March 23, 2011 So..chances are the noise is coming from a Power Tube, right? sorry I'm kind of ignorant of this technical stuff.. Any tube would cause it. Does it get worse the the gain/volume turned up or the master volume turned up? Either way, it wouldn't hurt to swap the tubes.... (Did you try the pencil tap test?)
pressure Posted March 23, 2011 Posted March 23, 2011 Check the tube chart on the inside of the amp to make sure the preamp tubes are the correct tubes in their sockets. A 12ax7 in a 12ay7 socket will change things. They look the same and fit the same but the gain is different.
smurph1 Posted March 23, 2011 Author Posted March 23, 2011 Any tube would cause it. Does it get worse the the gain/volume turned up or the master volume turned up? Either way, it wouldn't hurt to swap the tubes.... (Did you try the pencil tap test?) Yep..When I turn the volume up the noise gets louder..and when I did the pencil tap test, it seemed like all of them picked up the tapping..Thank God I've got another amp to use for the Gig Saturday..
DetroitBlues Posted March 23, 2011 Posted March 23, 2011 Yep..When I turn the volume up the noise gets louder..and when I did the pencil tap test, it seemed like all of them picked up the tapping..Thank God I've got another amp to use for the Gig Saturday.. Certainly sounds like you broke some tubes!
TalismanRich Posted March 23, 2011 Posted March 23, 2011 I've got 4 small tubes and 3 big ones..Are the small ones the pre-amp tubes?..If so, I do have a brand new pre amp tube.. The Classic 30 has 4 EL84 power tubes, and 3 12AX7 preamp tubes. The 12aX7 is a very common tube, just about everyone uses them. Probably $10-15. EL84s are pretty common as well. Most music stores will have them. JJs usually run about $20 or so each. Eurotube has full sets for the CL30. They run about $75 for a JJ set. Its strange that the hum got so much worse when you removed the cage. Usually that only would affect the shielding, since the cage shouldn't have any signal going through. My Classic is older and doesn't have a cage, just the tube tamer that I installed.
smurph1 Posted March 24, 2011 Author Posted March 24, 2011 The Classic 30 has 4 EL84 power tubes, and 3 12AX7 preamp tubes. The 12aX7 is a very common tube, just about everyone uses them. Probably $10-15. EL84s are pretty common as well. Most music stores will have them. JJs usually run about $20 or so each. Eurotube has full sets for the CL30. They run about $75 for a JJ set. Its strange that the hum got so much worse when you removed the cage. Usually that only would affect the shielding, since the cage shouldn't have any signal going through. My Classic is older and doesn't have a cage, just the tube tamer that I installed. Yeah..I thought that was strange too..Guess I'll just re-tube it..I have been hauling around a lot lately, so who knows? Thanks Ya'll..
smurph1 Posted March 24, 2011 Author Posted March 24, 2011 Yeah..I thought that was strange too..Guess I'll just re-tube it..I have been hauling around a lot lately, so who knows? Thanks Ya'll..
DetroitBlues Posted March 24, 2011 Posted March 24, 2011 That's why its always recommended to carry a spare set of tubes whenever you gig just in case they break. Just remember, they are sort of like light bulbs. And just like light bulbs, if you shake them around too much, the filaments inside seperate....
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