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GMC Forum _ GEAR & PRODUCTION _ Changing Tubes
Posted by: Fsgdjv Feb 6 2009, 02:10 PM
Hello 
My amp has recently started to sound a bit weird, there's this constant noise when it's turned on, like a constand buzz or something, and I'm trying to figure out what it is.
My first theory is that I need to change the tubes, but I have no idea if that's the case, but I thought I could ask how you know when it's time to do that? And if it's time to do that now, how do I do it? 
Anyways, any help will be deeply appreciated, since I'm clueless when it comes to gear.
Posted by: fatb0t Feb 6 2009, 02:31 PM
I just changed my tubes last night so I know abit about this.
I had to change my tubes because if my amp was on for longer than an hour or played at a volume >4 it would make cracking and popping noises. I went to eurotubes.com and ordered a new set for my MesaBoogie - I played all night with out an issue. So new tubes fixed that issue...
A constant noise doesn't seem like it would be a tube issue though... I would say check your instrument cables, try a different wall socket, make sure your guitar input jack is grounded properly, try a different cable, take a look at the tubes - any one in particular glowing brighter than the others or any tube not lit at all?
Let me know what you find out.
Posted by: DaniHel Feb 6 2009, 02:40 PM
Just a litte curiosity, the appartment where i live is quite old so when it was made they didnt ground the sockets. ´Till very recently if i was playing guitar and touched the top of the pc (the actual pc, not the mouse, monitor, etc) i would get shocked
But it´s all grounded now haha
Posted by: Ivan Milenkovic Feb 6 2009, 03:41 PM
Could be the tubes man, but check out first other gear that you have. Possibly somewhere else is the problem. Just to make sure before you buy a new set of tubes, check the cables, guitar, try different wall socket.
BTW what amp do you have and how old are the tubes in it?
Posted by: Fsgdjv Feb 6 2009, 06:13 PM
I've tried with different guitars, cables and wall sockets now, the buzzing is still there. It's not really bad though so I can probably live with this for a while, but I'll have to change them soon I guess.
The amp is a Peavy Valveking 112, and I bought it one and a half year ago, so it feels like the tubes should be good for a while longer.
Posted by: fatb0t Feb 6 2009, 07:00 PM
Some tubes crap out earlier than others...just the way it is... Make sure they're in their respective slots tightly. Order a new set of tubes, they're about 100 bucks if all else fails...
Posted by: Ivan Milenkovic Feb 6 2009, 10:12 PM
You can get a new set of tubes if you haven't changed them since you bought it. In general they don't put the best tubes in finished amps, they tend to put the cheapest so they lower down the price. So a nice fresh set would definitely do you good. I recommend JJ tubes, they are great bang for buck. You can swap them yourself, just carefully remove all the tubes out, and put new tubes it and put the pins in the same positions.
How many power tubes there are in the ValveKing and what tubes does it use?
Posted by: Fsgdjv Feb 7 2009, 05:21 PM
There are 2 power tubes, "6L6GC" is what it says over the tubes, so I suppose that's the kind of tubes it uses, even though I have no idea about this stuff.
The preamp tubes are 3x "12AX7", but I don't have to change them, right?
I'll look up JJ tubes, I feel like I really need to educate myself when it comes to the tubes
Posted by: utak3r Feb 7 2009, 07:01 PM
Just beware it keep this in your mind: capacitors in the tube amp's powering circuits CAN KILL YOU. You HAVE TO know what you're doing!
Posted by: Fsgdjv Feb 8 2009, 03:12 AM
And that is why I'm trying to find out things about it before doing it, but thank you anyways 
Posted by: Alex87 Feb 8 2009, 06:27 PM
My amp has recently started to sound a bit weird, there's this constant noise when it's turned on, like a constand buzz or something, and I'm trying to figure out what it is.
My first theory is that I need to change the tubes, but I have no idea if that's the case, but I thought I could ask how you know when it's time to do that? And if it's time to do that now, how do I do it?
Anyways, any help will be deeply appreciated, since I'm clueless when it comes to gear.
This issue your talking about here is 100% identical to the thing my amp suffers from. Tried alot, still no results. You come up with something let me know
and visa verse ofcourse
Posted by: Fsgdjv Feb 8 2009, 09:49 PM
Did you try changing the tubes?
And my amp only sounds like that when it's on the drive channel, at least today, yesterday it affected both channels
I don't know if that makes any difference, but if anyone knows anything, it'd be great to hear.
And would a matched pair of these power tubes be a good choise? https://ssl.eurotubes.com/cart/index.php?page=view_products&category_id=3&sub_category_id=22
Posted by: MickeM Feb 8 2009, 10:01 PM
Drop them an e-mail, they are both helpful and talkative. It's possible they could suggest you a matched set based on what you tell them you'd like from your amp. I.e earlier breakup, lots of bottom etc.
I've ordered tubes from them and was told I could choose betwee a few different characteristics.
Posted by: Ivan Milenkovic Feb 9 2009, 12:53 AM
Check out http://www.eurotubes.com/ - all the info on tubes you'll need and then some.
Posted by: Sircraigery Mar 21 2009, 01:17 AM
Get a matched pair of 6L6's for sure. If you don't want to bias the amp next time you change tubes, buy a matched quartet.
I'm not sure if the preamp tubes, 12ax7's, have to be matched. They are not used together like power tubes, they are used one after another (in a series chain). So my guess is that they do not have to be matched. (Someone know?).
I would buy MESA tubes, they test each one with some robotube thing they made. If it doesn't pass inspection, for signal or projected life, then they throw the tube away (or sell it to a wholesaler). They are about $60 for a set of 6L6's I believe.
Also, go to a store, don't have them shipped from an online source. I would be too worried that they would be no good, then how can you take them back?
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