Is it time to get new tubes?

hilljack13

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Tonight my amp went a bit bizerk. Mesa four channel amp decided to auto switch channels 3&4, but on the amp both channels were lit. The foot switch took a moment to get things right. I unplugged the foot switch, plugged back in and seems to be working. I check the back and this picture is what I see. Not all tubes are looking the same. I did buy this used a year ago so I am thinking it might be time for a new set of tube? Thoughts?
IMG_20220521_193018.jpg
 

Deadpool_25

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Someone correct me if I’m wrong but it doesn’t sound like a tube issue to me. Sounds like a possible footswitch or cable issue. If you unplugged and reconnected it and it’s working now you’re probably fine.

Does it sound like it should?
 

hilljack13

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After about an hour seems fine. We have had some storms today so hope that might be it. OK for now..
 

c7spheres

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I know with some Mesa's it's standard procedure to plug in everything first, power on, then cycle through all the channels and swtiches to also prevent some popping etc. Both channels on at same time kinda odd though I'd think. Possible a relay is starting to go somewhere. You'll know cause it'll freak out and you'll hear a bunch of clicking sounds, I guess they could both stick too causing both cahnnel to be one maybe. I dunno. Hopefully nothing ever happens again like that, but I'd still be wiggling cables and jacks and tapping on stuff to see if it messes up again or not.
 

Grindspine

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Two of the tubes are the rectifier tubes on the left of the picture. The power tubes are the glowing ones. As said above, it does not sound like a tube issue.

Edit: Actually is that a dual rec? The tubes on the left look like they say Mesa 5U4GB, which are rectifier tubes. The other tubes look like JJs. Either way, it does sound like an issue with the footswitch or footswitch cable.
 

TheWarAgainstTime

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It could be something as simple as a dirty connection/jack on the footswitch, cable, or footswitch jack on the back of the amp, especially if everything is back to normal now. Probably just a reminder to hit your gear with some electronics duster and/or Deoxit once in a while :shrug: c7spheres also brought up a good point about cycling through the channels/functions when you power on the amp. I used to have to do that with my older Triple Rectifier to prevent popping sounds when I would change channels.

If the problem persists, then you may need to have a tech look at it and check the relays and related parts that handle the channel/function switching. If any of those start to go, it could cause the amp to jump between channels or override the footswitch randomly.

Either way, tubes wouldn't have anything to do with this particular problem. The two 5U4 tubes on the left side serve a different purpose than the four power tubes, so the difference in glow is totally normal.
 

guitar_player4_2_0

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Just wanna throw out the obvious because you mentioned storms, you do have that plugged into some kind of power conditioner/surge protection, right? Tubes look ok to me, especially after I realized the far two were rectifier tubes like a few pointed out lol.
 


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