Dub-T-123 Posted September 10, 2010 Share Posted September 10, 2010 I've been having a problem with the ac30 for about a month and a half. I was playing it and all the sudden the sound just slowly faded away. Like a fade out at the end of a song. It would be pretty cool if it didn't totally suck. So I looked at the tubes (with the power on) and noticed all of the tubes but one were glowing. I narrowed the problem down to that tube. So I turned it off and let the tubes cool down and then I took the vent off and wiggled the tube gently to see if I could just sort of re-seat it. It worked and the amp worked fine. Then one day I turned the power on and waited for the tubes to warm up. I hit the standby switch and the little green light didn't turn on. No sound. So I'm thinkin ok I'll just wiggle the tube around a little bit again. So I popped the vent off again and felt the tube to see if it would melt my fingers. It didn't melt my fingers so I wiggled it around and the amp came back to life. I did this with the power on. So this has become sort of a regular thing now. If the little green light doesn't come on, it's time to start wiggling. I do it with the power on so I can see if it works right away. So do you think I'll die from this? If I did get electrocuted would it be like sticking my finger in a lightbulb socket jolt stuff or like bam my freakin heart explodes and my hair bursts into flames stuff? I've done like everyday for a while and nothings happened. But everyones always talking about how dangerous that kindof stuff is. Link to comment Share on other sites More sharing options...
flyingarmadillo Posted September 10, 2010 Share Posted September 10, 2010 I've been having a problem with the ac30 for about a month and a half. I was playing it and all the sudden the sound just slowly faded away. Like a fade out at the end of a song. It would be pretty cool if it didn't totally suck. So I looked at the tubes (with the power on) and noticed all of the tubes but one were glowing. I narrowed the problem down to that tube. So I turned it off and let the tubes cool down and then I took the vent off and wiggled the tube gently to see if I could just sort of re-seat it. It worked and the amp worked fine. Then one day I turned the power on and waited for the tubes to warm up. I hit the standby switch and the little green light didn't turn on. No sound. So I'm thinkin ok I'll just wiggle the tube around a little bit again. So I popped the vent off again and felt the tube to see if it would melt my fingers. It didn't melt my fingers so I wiggled it around and the amp came back to life. I did this with the power on. So this has become sort of a regular thing now. If the little green light doesn't come on, it's time to start wiggling. I do it with the power on so I can see if it works right away. So do you think I'll die from this? If I did get electrocuted would it be like sticking my finger in a lightbulb socket jolt stuff or like bam my freakin heart explodes and my hair bursts into flames stuff? I've done like everyday for a while and nothings happened. But everyones always talking about how dangerous that kindof stuff is. As long as you don't touch anything but the glass tubes you're okay, however you can get into trouble if you touch a wire or the wrong spot on a PCB. The plate voltages on the tubes are around 300V - that might kill you - The really dangerous part of amps is that the capacitors in the power supply can stay charged after the amp is turned off. That could zap you even if it's unplugged. I once accidentally discharged a power capacitor on a solid state amp and it drilled a hole right through a 1/4 cast aluminum heat sink! BTW, the oil from your skin can cause hot spots on the tubes and potentially shorten their life. Link to comment Share on other sites More sharing options...
Dub-T-123 Posted September 10, 2010 Author Share Posted September 10, 2010 All I touched was that one tube and the little spring collar that holds it down. Think the problem is the socket that the tube plugs into. Any way I can easily fix that? Should I try some contact cleaner or something? I really don't have the money to send it to a tech. The problem seems fairly simple. At least I know where the problem is. Thanks for the info Link to comment Share on other sites More sharing options...
flyingarmadillo Posted September 10, 2010 Share Posted September 10, 2010 Get some contact cleaner from an electronics store and spray it on both the pins on the tube and in the socket. Seat and reseat the tube a couple times. That should take care of any corrosion. If the socket is going bad, that would need a tech if you're not good at soldering. If you can look at the socket see if there are any loose wires or bad solder joints. Before you poke around too much make sure the amp has been turned off and unplugged for at least an hour - that should allow the power caps to bleed down naturally although overnight would be safer. You might go to the Vox website and poke around the forums there. I don't think you're the first one to have this problem. Link to comment Share on other sites More sharing options...
Dub-T-123 Posted September 10, 2010 Author Share Posted September 10, 2010 Thanks for the help man! If I end up needing to do some soldering I'll have my brother do it. I can do it but I'm sloppy. He's great at it. Link to comment Share on other sites More sharing options...
dem00n Posted September 10, 2010 Share Posted September 10, 2010 Get some contact cleaner from an electronics store and spray it on both the pins on the tube and in the socket. Seat and reseat the tube a couple times. That should take care of any corrosion. If the socket is going bad, that would need a tech if you're not good at soldering. If you can look at the socket see if there are any loose wires or bad solder joints. Before you poke around too much make sure the amp has been turned off and unplugged for at least an hour - that should allow the power caps to bleed down naturally although overnight would be safer. You might go to the Vox website and poke around the forums there. I don't think you're the first one to have this problem. Even if its the socket is going bad, i wouldnt trust my self fixing it! An amp is at least 10 times more complaicted then a guitar. Link to comment Share on other sites More sharing options...
Dub-T-123 Posted September 10, 2010 Author Share Posted September 10, 2010 Well it's a pretty simple part of the amp. I'm smarter than I make myself seem lol. Link to comment Share on other sites More sharing options...
dem00n Posted September 10, 2010 Share Posted September 10, 2010 Well it's a pretty simple part of the amp. I'm smarter than I make myself seem lol. I know that Im just saying, im sure we all have heard stories of guys ****ing their amps up. Link to comment Share on other sites More sharing options...
freak show Posted September 10, 2010 Share Posted September 10, 2010 Even if its the socket is going bad, i wouldnt trust my self fixing it! An amp is at least 10 times more complaicted then a guitar. Actually, dem00n speaks with the wisdom of many m00ns. A tube amp can be a very dangerous piece of equipment. If you want to work on it yourself, talk to someone who really understands how to do that kind of stuff first. There are rules to working on tube amps that you have to follow in order to avoid grilling yourself. Link to comment Share on other sites More sharing options...
pippy Posted September 10, 2010 Share Posted September 10, 2010 Actually, dem00n speaks with the wisdom of many m00ns. A tube amp can be a very dangerous piece of equipment. If you want to work on it yourself, talk to someone who really understands how to do that kind of stuff first. There are rules to working on tube amps that you have to follow in order to avoid grilling yourself. +1. We'd miss you 'round here, Dub.............. Link to comment Share on other sites More sharing options...
badbluesplayer Posted September 10, 2010 Share Posted September 10, 2010 The most important thing to do when you're sticking your hand into an amp. Keep your other hand (and the rest of your body) from touching the amp or anything grounded. Keep your other hand in your pocket or somewhere else so you don't touch anything grounded. Link to comment Share on other sites More sharing options...
Silenced Fred Posted September 10, 2010 Share Posted September 10, 2010 The only good part is... 300 volts probably won't kill you. It would literally throw you off the amp as long as you didn't hold on or something, but I wouldn't risk it. I will tinker with guitars, but amps?.... No way Link to comment Share on other sites More sharing options...
saturn Posted September 10, 2010 Share Posted September 10, 2010 There's also a way to discharge those filter caps. Either with an insulated screwdriver (the loud way) or a resistor with aligator clips. A quick search will bring up many examples of how to do this. Link to comment Share on other sites More sharing options...
dbreslauer Posted September 10, 2010 Share Posted September 10, 2010 The most important thing to do when you're sticking your hand into an amp. Keep your other hand (and the rest of your body) from touching the amp or anything grounded. Keep your other hand in your pocket or somewhere else so you don't touch anything grounded. +1 keep the current from going through your chest, in a worst case scenario. Do not BE the path of least resistance... better yet, if in any doubt, take it to a pro. it is surprising to some how little voltage can kill you, and how much is in that amp. Link to comment Share on other sites More sharing options...
G McBride Posted September 10, 2010 Share Posted September 10, 2010 Do Not Put Your Hand in your pocket. You wouldn't want that electricity to flow from the hand touching the tube to the hand pointed at your personal parts. Might be kind of painful. Link to comment Share on other sites More sharing options...
BigKahune Posted September 10, 2010 Share Posted September 10, 2010 Do Not Put Your Hand in your pocket. You wouldn't want that electricity to flow from the hand touching the tube to the hand pointed at your personal parts. Might be kind of painful. Now there's a brutal thought. Link to comment Share on other sites More sharing options...
dbreslauer Posted September 10, 2010 Share Posted September 10, 2010 Now there's a brutal thought. But, if current did somehow travel from hand in amp to hand in pocket, it will likely have already gone through your heart: you probably won't even notice... seriously though, it is a good safety rule. you're less likely to be the "wire" in a short circuit, so to speak. Link to comment Share on other sites More sharing options...
Dub-T-123 Posted September 10, 2010 Author Share Posted September 10, 2010 Hmm. I've been doing it two-handed most of the time LOL. I'll keep that in mind. I just need to get some time to really open it up so I can see what's going on. Link to comment Share on other sites More sharing options...
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