Members Bricks & Bones Posted July 27, 2010 Members Share Posted July 27, 2010 ...into a Blue Light Disco.But that amp still responds as usual.Should I...A. Take it to a Tech. B. Get naked and dance, dance, dance.C. Call the Police. Link to comment Share on other sites More sharing options...
Phil O'Keefe Posted July 27, 2010 Share Posted July 27, 2010 B. But please wait until I leave... Seriously - a blue glow to tubes is generally not a problem. When they glow BRIGHT red hot, they're about to go... a soft orange glow is generally OK too. Link to comment Share on other sites More sharing options...
Members Bricks & Bones Posted July 27, 2010 Author Members Share Posted July 27, 2010 Ah ok. Thanks Phil. Like I said, the amp runs fine. The blue glow might have always been there and I just never noticed.Is it possible for tubes to suddenly get a blue glow? Link to comment Share on other sites More sharing options...
Phil O'Keefe Posted July 27, 2010 Share Posted July 27, 2010 Yeah, I suppose... but I think it's probably more likely that it was always there and you just never really noticed. Link to comment Share on other sites More sharing options...
Members melx Posted July 27, 2010 Members Share Posted July 27, 2010 Ah ok. Thanks Phil. Like I said, the amp runs fine. The blue glow might have always been there and I just never noticed. Is it possible for tubes to suddenly get a blue glow? Sometimes handling them (with bare hands) will make them glow blue. My mate used to do it on purpose because you could see them through the front of his head and he thought it looked cool. Link to comment Share on other sites More sharing options...
Members ambient Posted July 27, 2010 Members Share Posted July 27, 2010 Ah ok. Thanks Phil. Like I said, the amp runs fine. The blue glow might have always been there and I just never noticed.Is it possible for tubes to suddenly get a blue glow? Power tubes glowing blue/purple usually result from the amp being turned on with out a load attached, ie your amp may have been used without speakers which is NOT a good thing to do. I'm not sure but it might be able to be cause by an impedance mismatch as well (?). It is also possible that you have a bad connection somewhere with your speaker cable/jacks or even somewhere in the output stage of the amp. I'm no amp tech but I believe the blue/purple colour results from a build up of charge feeding back into the power stage of the amp then oxidising something within the tubes. The strange colour in and of itself does not necessarily mean the tubes are bad, but operating an amp under these conditions can is very unhealthy for your gear and can result in some nasty issues. I would strongly suggest getting it looked at by a tech before using it again just to be on the safe side - you never know what other components might be having issues and what consequences you get if you keep using it. tl;dr - take it to a tech. Link to comment Share on other sites More sharing options...
Members Bricks & Bones Posted July 27, 2010 Author Members Share Posted July 27, 2010 Great Post ^^^^^ Thanks! Link to comment Share on other sites More sharing options...
Members ambient Posted July 27, 2010 Members Share Posted July 27, 2010 Great Post ^^^^^Thanks! tbh that's all 2nd hand information so I may be somewhat full of {censored}. I'd still play it safe and have someone take a peak. Some google-ing has revealed that there are a few causes for blue glow. Some tube types are more blue than others. What type of tubes are they? Is it intense blue or just a tinge? This thread needs Andreas... Link to comment Share on other sites More sharing options...
Members Bricks & Bones Posted July 27, 2010 Author Members Share Posted July 27, 2010 They're 6v6 or 6L6. What ever is in a Vibrolux Reverb.The blue isn't hard intense. And it's defined to lines rather than an all over glow. Kinda looks like arcing. Link to comment Share on other sites More sharing options...
Phil O'Keefe Posted July 27, 2010 Share Posted July 27, 2010 Dude... it's almost certainly fluorescence, and NOTHING to worry about. Seriously, if you feel it needs to be looked at, and the "blue tubes" is the ONLY "symptom" your amp has, take a video or picture and toss it up and I'll have a look. But from what you're describing, even without the pic, I'd be willing to bet there is nothing to worry about. Link to comment Share on other sites More sharing options...
Members ambient Posted July 27, 2010 Members Share Posted July 27, 2010 Not that I can tell you anything, but can you get a decent photo? Someone with a similar amp/tubes maybe able to tell if it's normal. When did you last replace the tubes and did you get it re-biased? Link to comment Share on other sites More sharing options...
Phil O'Keefe Posted July 27, 2010 Share Posted July 27, 2010 Here's a couple of articles you can read on the subject to help put your mind at ease - and a couple of pics too: http://www.netads.com/~meo/Guitar/Tubes/blue_glow.html http://www.jacmusic.com/html/articles/blueglow/blueglow.htm ^^^ Completely normal. Link to comment Share on other sites More sharing options...
Members Dr.Pain-MD Posted July 27, 2010 Members Share Posted July 27, 2010 Blue glow is perfectly fine, it's caused by some loose electrons in the vacuum or something like that. No need to take it to a tech. Link to comment Share on other sites More sharing options...
Members ambient Posted July 27, 2010 Members Share Posted July 27, 2010 show's what I know But seriously if you turn your amp on with no speakers/load attached your tubes often turn go blue. Do it for too long and it causes issues. Obviously not the only cause. Link to comment Share on other sites More sharing options...
Phil O'Keefe Posted July 27, 2010 Share Posted July 27, 2010 I've never heard that plugging your amp in without a load causes the tubes to turn blue. I DO know that plugging your amp in without a proper load can cause Very Bad Things to happen - like blown transformers, fried parts - tubes, resistors, etc. And it doesn't take long, so avoiding that scenario completely is HIGHLY recommended. IOW, don't try experimenting to see if you can get your tubes to glow blue by connecting the amp without a load - ALWAYS run your amp with the correct impedance load connected! Link to comment Share on other sites More sharing options...
Members ambient Posted July 27, 2010 Members Share Posted July 27, 2010 I've never heard that plugging your amp in without a load causes the tubes to turn blue. I DO know that plugging your amp in without a proper load can cause Very Bad Things to happen - like blown transformers, fried parts - tubes, resistors, etc. And it doesn't take long, so avoiding that scenario completely is HIGHLY recommended. IOW, don't try experimenting to see if you can get your tubes to glow blue by connecting the amp without a load - ALWAYS run your amp with the correct impedance load connected! Absolutely.But I'm pretty sure I'm not making it up.....reasonably sure. Link to comment Share on other sites More sharing options...
Members Dr.Pain-MD Posted July 27, 2010 Members Share Posted July 27, 2010 I've never heard that plugging your amp in without a load causes the tubes to turn blue. That's why SS amps rule, no load = no problem. Link to comment Share on other sites More sharing options...
Members Bricks & Bones Posted July 27, 2010 Author Members Share Posted July 27, 2010 Pictures I'm tying to take are really unclear. From what you all are saying it's nothing to worry about. Thanks for all the info! Link to comment Share on other sites More sharing options...
Members ambient Posted July 27, 2010 Members Share Posted July 27, 2010 That's why SS amps rule, no load = no problem. You can get SS amps to overheat by running at an impedance that is too low for too long though (less than 2 ohms for some amps). But in my experience it doesn't seem to hurt anything, just trips some sort internal failsafe that stops it working for 15 mins or so. Link to comment Share on other sites More sharing options...
Members Dr.Pain-MD Posted July 27, 2010 Members Share Posted July 27, 2010 Yes that is indeed true, but no load is basically infinite impedance which is perfectly safe in most SS amps (ones without output transformers anyways). Link to comment Share on other sites More sharing options...
Members andreas Posted July 27, 2010 Members Share Posted July 27, 2010 This thread needs Andreas...At your service... I'm with Phil - a light blue glow from the filaments (the thingamagooks inside the tube) is just fine, and if the amp works as normal (normal sound, and no change in the sound over time) it's all ok. It's different if the glow seems to come from the whole tube (glass and all), but as long as it comes from inside the tube, it's ok. A bright red glow from the whole tube (glass and all) is bad - the tube is either on its way out, the heater voltage is wrong or the bias voltage is completely off. But in all those cases, you'll definitely hear it too. Keep in mind that the colour of the glow will change with the viewing angle. In a Fender amp the tubes (6L6's in the Vibrolux) hang from the chassis, so when you lean over the back of the amp to check, you're looking right in between the filaments. If you view the tubes from the rear, at level height, the glow might look different. /Andreas Link to comment Share on other sites More sharing options...
Members RoboPimp Posted July 27, 2010 Members Share Posted July 27, 2010 turning me on without plugging me into something causes me to turn blue Link to comment Share on other sites More sharing options...
Members english_bob Posted July 27, 2010 Members Share Posted July 27, 2010 I heard that this indicates poor performance of the crystal lattice. Those loose electrons are the weak ones carrying inferior frequencies that can't pass through, and they'll contribute to a buildup of bad tone in your amp until everything sounds like ass. Bottom line: you needs a Dumble. Link to comment Share on other sites More sharing options...
Members RoboPimp Posted July 27, 2010 Members Share Posted July 27, 2010 the ONLY glow you need to look out for IMO is "cherry spots" on the plates...you'll know why they're called that when you see it or you'll be able to tell when they're cooled off, there's a significant distinct darker circle on the centers of the platesedit: / bobby d has ME doing the CAPS thing Link to comment Share on other sites More sharing options...
Members RoboPimp Posted July 27, 2010 Members Share Posted July 27, 2010 I heard that this indicates poor performance of the crystal lattice. Those loose electrons are the weak ones carrying inferior frequencies that can't pass through, and they'll contribute to a buildup of bad tone in your amp until everything sounds like ass.Bottom line: you needs a Dumble. dumble's bottom line is not something to be mocked, it's quite expansive Link to comment Share on other sites More sharing options...
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