Curious why my Mesa Rectifier is doing this...

[ChrisCst22]

This is my newly aquired Mesa Dual Rec Reborn. Well, the amp anyway. The chassis is out at a luthier retolexing it hot white to match my Recto cab, and my other Mesa half stack.

I'm just curious why one power tube is so much brighter than the others. It really concerned me at first, but after a month of playing the amp, I really don't hear any problems. The amp sounds great! When I switch from 100 watts to 50 watts, which should be taking that tube out of the signal path, I hear no difference in tone or hum, just lower volume. It's kinda strange, and I'm curious what will happen when I decide to change the tubes. It'll be a while because I certainly don't want to touch anything now, it sounds fantastic right now! Any ideas?

 

[xjbebop]

Tubes often glow at different rates.
As for the workings, you should call Mesa. Their customer service is outstanding.
They designed & built the amp, not PRS....

 

[László]

Tubes can have different glows. Mesa matches theirs for certain things, but glow probably isn't one of them. Still, Bebop's right, Mesa's customer service can give you the skinny.

As an aside, that thing looks pretty darn cool in the rack without the headshell!

 

[yakbass]

This is my newly aquired Mesa Dual Rec Reborn. Well, the amp anyway. The chassis is out at a luthier retolexing it hot white to match my Recto cab, and my other Mesa half stack.

I'm just curious why one power tube is so much brighter than the others. It really concerned me at first, but after a month of playing the amp, I really don't hear any problems. The amp sounds great! When I switch from 100 watts to 50 watts, which should be taking that tube out of the signal path, I hear no difference in tone or hum, just lower volume. It's kinda strange, and I'm curious what will happen when I decide to change the tubes. It'll be a while because I certainly don't want to touch anything now, it sounds fantastic right now! Any ideas?

Simplest way to sort out what's going on is to swap the tube into another position and see if the tube or the tube position is where the bright glow is at. Most likely it will be the tube.
If it is, play it till it stops glowing. Remember to to: a. Turn it off, and b. let the tubes cool prior to touching them, c. try to avoid getting oil from your fingers on the tubes ( it can cause hot spots in the tube).

If the position is the source of the bright tube, call MESA and discuss it with them.

Good luck.

 

[rugerpc]

Am I missing something?

There is nothing wrong with the amp, it functions as it should?

One tube appears/glows brighter than the others - that's the only thing wrong here?

And the suggestion is to start taking it apart and moving things around???

Glad you guys aren't working on my stuff.

Leave it alone. Call Mesa. Ask questions.

 

[Drew]

The single power tube glowing brighter than the others was the first sign of my old Mesa Nomad going kaput. Have the amp serviced. Do not do what I did which is to keep playing the amp. There is an obvious issue there.

 

[ChrisCst22]

They designed & built the amp, not PRS....

I realize that, but I'm not a member of any Mesa forum, just here. I feel like I know a lot of the regulars on here who seem to be down to earth, knowledgeable and willing to help out, so that's why I posted.

The single power tube glowing brighter than the others was the first sign of my old Mesa Nomad going kaput. Have the amp serviced. Do not do what I did which is to keep playing the amp. There is an obvious issue there.

Thanks Drew for sharing your experience. Hearing that is exactly why I wanted to ask around. I went ahead and swapped the two outer tubes. Thankfully the brightness switched as well so it seems to definitely be the tube. I do have an entire fresh set of tubes for it, but didn't want to swap out these ones as their brand new. I will try to reach out to Mesa sometime during the week for their input. Thanks!

 

[yakbass]

Am I missing something?

There is nothing wrong with the amp, it functions as it should?

One tube appears/glows brighter than the others - that's the only thing wrong here?

And the suggestion is to start taking it apart and moving things around???

Glad you guys aren't working on my stuff.

Leave it alone. Call Mesa. Ask questions.

Yeah, you are. Most of the answers I have seen here (including mine) seem to be from knowledgable people. Your advice to drive it until it breaks borders on stupid.

In electronics, when something is amiss, run down the problem before before it gets a lot worse. This advice comes from 45 years experience fixing electronic equipment (US Navy Combat Systems).
Some of the time they called when the problem was small and it was a quick fix. Other times they kept closing the breaker that kept tripping and called once the equipment melted.. Not so good.

Your previous post have been thoughtful and entertaining, so I'm assuming this post was predicated by something we don't need to know about.

And yeah, when all else fails, call the people who built it.

 

[rugerpc]

Am I missing something?

There is nothing wrong with the amp, it functions as it should?

One tube appears/glows brighter than the others - that's the only thing wrong here?

And the suggestion is to start taking it apart and moving things around???

Glad you guys aren't working on my stuff.

Leave it alone. Call Mesa. Ask questions.

Yeah, you are. Most of the answers I have seen here (including mine) seem to be from knowledgable people. Your advice to drive it until it breaks borders on stupid.

In electronics, when something is amiss, run down the problem before before it gets a lot worse. This advice comes from 45 years experience fixing electronic equipment (US Navy Combat Systems).
Some of the time they called when the problem was small and it was a quick fix. Other times they kept closing the breaker that kept tripping and called once the equipment melted.. Not so good.

Your previous post have been thoughtful and entertaining, so I'm assuming this post was predicated by something we don't need to know about.

And yeah, when all else fails, call the people who built it.

Read my post again - I did not say drive it until it breaks - I said "Leave it alone. Call Mesa. Ask questions." The exact opposite of what you got from that.

It is probably best not to assume that just anyone should dive into their amps without knowing their background, training and understanding of the deadly high voltage circuits involved. Lots of people here have the knowledge, but do you know who, specifically, does and does not? I make no such assumptions. And neither should you - one way or the other.

My answer caused no further harm to the amp and protected the life of the OP.

 

[John Beef]

Maybe it's just the angle of the photo but it looks like a different make of tube to me. The other three, the innards all look the same but in the brighter ones it looks like the plates are taller and the tube is fatter and there's not as much silver stuff in the top of it.

 

[ChrisCst22]

Maybe it's just the angle of the photo but it looks like a different make of tube to me. The other three, the innards all look the same but in the brighter ones it looks like the plates are taller and the tube is fatter and there's not as much silver stuff in the top of it.

Hey John, I see what your saying, and I think it's the angle of the photo. When your in front of them they look identical. All Mesa branded, definitely factory originals.

Thanks again for your input everyone. If I get more info from Mesa I'll post it here.

 

[László]

Yeah, you are. Most of the answers I have seen here (including mine) seem to be from knowledgable people. Your advice to drive it until it breaks borders on stupid.

In electronics, when something is amiss, run down the problem before before it gets a lot worse. This advice comes from 45 years experience fixing electronic equipment (US Navy Combat Systems).
Some of the time they called when the problem was small and it was a quick fix. Other times they kept closing the breaker that kept tripping and called once the equipment melted.. Not so good.

Your previous post have been thoughtful and entertaining, so I'm assuming this post was predicated by something we don't need to know about.

And yeah, when all else fails, call the people who built it.

I think Ruger was simply advising the OP to call Mesa, bottom line.

 

[aristotle]

Couple of comments...

First, questions like these, in my opinion, are great to ask on this forum. As it turns out, the answer is independent of whether this were a Mesa, a PRS, a Marshall, or any other manufacturer. The OP could have just called Mesa, sure...but the purpose of this forum (again, in my opinion) is to shed light (literally in this case) on the types of issues that guitarists and their gear encounter.

Now for the answer... It's very common for the filament in power tubes to be visually exposed differently between tubes of the same type, regardless of if they are matched. That's all you are seeing here, and it doesn't indicate anything at all wrong with the tube. It seems particularly true of EL34s, but this variability can even be seen with 12AX7s. The filament's job is to heat the tube. If the tube is working and generating output, the filament is working.

If the plate were starting to glow red on one of the tubes though (and it's not in the picture above), it would mean it's biased wrong, and would be a cause for concern.