| Author |
Topic: Glowing tube problem |
Tommy Boswell
From:
Virginia, USA
|
Posted 6 Oct 2015 8:04 pm |
|
Watching my tubes glow through the cloth grill is almost as much fun as listening to them, but tonight I noticed one of the power tubes glowing from top to bottom like I've never seen before, like it might be over-heated or something. I Also heard some unexpected break up. Only one of the two power tubes was glowing that way. Is that likely to be a tube going bad? Or something wrong with the amp?
I was not over-driving it by any means. The tubes are fairly new Ruby 6L6GCMSTR, and the amp is a Frenzel Mini-Bassman. Any help is appreciated. |
|
|
 |
Patrick Ickes
From:
Upper Lake, CA USA
|
Posted 6 Oct 2015 8:46 pm
|
|
I had the same problem with a brand new Peavey DB210. Very slight "something don't sound right" and a glowing power tube.
Sounds like a tube going south. Swap your power tubes and see if the glowing tube stays with the socket or follows the tube. If it follows the tube, replace it, if it stays at the socket, it's amp tech time, or someone here will give you a fix.
Patrick |
|
|
|
Donny Hinson
From:
Glen Burnie, Md. U.S.A.
|
Posted 7 Oct 2015 6:55 am
|
|
| Tommy's suggestion is a good one. If the plate gets cherry-red, it's a pretty good sign the bias is way off, and most of the time, that's caused by an inter-electrode short in the tube and it should be replaced. |
|
|
|
Stephen Cowell
From:
Round Rock, Texas, USA
|
Posted 7 Oct 2015 5:52 pm
|
|
These tubes should be biased when they are installed... from the sound of it, you'd recently replaced them and hadn't set the bias. Cherried-up tube is the result... when you replace the carburetor, set the idle! If you aren't confident learning how to set your own bias you need to see a technician about it.
_________________
New FB Page: Lap Steel Licks And Stuff: https://www.facebook.com/groups/195394851800329 |
|
|
|
Tim Marcus
From:
San Francisco, CA
|
Posted 8 Oct 2015 6:58 am
|
|
swap the tubes around and see if the glowing follows the tube or not.
If yes: bad tube
If no: bad amp
_________________
Milkmansound.com |
|
|
|
Tommy Boswell
From:
Virginia, USA
|
Posted 9 Oct 2015 5:11 am
|
|
Amp is fixed-bias. I could not repeat the problem, so just for good measure I put the factory original J/Js back in, they sound and work great.
Thanks for all the responses. |
|
|
|
