Red plating tube in Herbert

[BigR]

Was playing through my Herbert today, and after maybe a minute or two of playing, I started hearing a popping static type sound. I looked and noticed that tube #1 (the farthest left when looking from the rear of the amp) appeared to be red plating. I've never had a tube red plate in any of my amps, but all or nearly all of the metal inside the tube was glowing VERY bright orange, so I assume it was redplating. I immediately turned off the amp, and let it cool down. I turned it back on, and it seemed to be running fine-no fuses were blown, and all 6 tubes were lit as normal. I played through it for a few minutes, and it sounded the same (i.e., great) as it should.
I double checked, and everything was hooked up correctly-cabs in correct outputs, etc. My question is, should I replace tube #1 (and #6 to keep the tubes matched pairwise), or should it be ok since it ran just fine after I turned it off and back on. The only thing I did different was not let it warm up as long as I normally do in standby-maybe a minute vs the 5 or more minutes I normally warm it up. I don't know what causes red plating, especially when the amp is running normally now, and if it could be just a freak occurrence. The voltage going into the amp was at 119 according to my Furman, which is where it normally is during the day, so I don't think I had a voltage spike or anything. Any help or advice would be appreciated. I have extra tubes, so retubing isn't a problem, but I'd rather save em if possible. If it matters, the tubes in the amp are the originals ( I bought it in April 2008), and are TAD EL34 STR.

Rich

 

[Peter Diezel]

If the tube is redplating again, replace it.

 

[BigR]

Ok, thanks Peter.

 

[BigR]

One more question, Peter (or anyone could insufficient warm up time cause the tube to red-plate? I did warm it up in standby for 45sec to a minute, which I assume is long enough, but I normally warm it up for 5 min +.

 

[Joeytpg]

Olaf and Peter have said that 30 sec. to 1 min. it's ok. and if you're gonna switch it off, 3 - 10 sec. is ok.

 

[King Crimson]

If it matters, the tubes in the amp are the originals ( I bought it in April 2008), and are TAD EL34 STR.

Rich

You should have Ruby EL34BSTR:

Same tube but, you know...

Manual attached pg. 2.1.2.

 

[BigR]

Olaf and Peter have said that 30 sec. to 1 min. it's ok. and if you're gonna switch it off, 3 - 10 sec. is ok.

Thanks. I thought I'd read something like that in the manual, but didn't have it handy when I asked the question. Just a little paranoid, I guess, and want to make sure it was nothing that I did that caused it.

If it matters, the tubes in the amp are the originals ( I bought it in April 2008), and are TAD EL34 STR.

Rich

You should have Ruby EL34BSTR:

Same tube but, you know...

Manual attached pg. 2.1.2.

Thanks, King Crimson. I think they probably are relabelled Rubys. The side of the tube says TAD, and EL34B-STR below that (i forgot the "B" on my earlier post). The base of the tube is brown/orange, and there is a sticker on each tube base that says "Tube Amp Doctor Selected 3".
Its not that big a deal as long as they work and sound good, until it comes time to retube. Then I'd want to know what brand of tube is in the amp, so I know whether to go with a different brand or not.

 

[King Crimson]

Thanks, King Crimson. I think they probably are relabelled Rubys. The side of the tube says TAD, and EL34B-STR below that (i forgot the "B" on my earlier post). The base of the tube is brown/orange, and there is a sticker on each tube base that says "Tube Amp Doctor Selected 3".
Its not that big a deal as long as they work and sound good, until it comes time to retube. Then I'd want to know what brand of tube is in the amp, so I know whether to go with a different brand or not.

Yah, I know BigR. It gets quite confusing when suppliers re-label tubes. You never know exactly what you’re getting unless you put it under a scope even though the construction physically appears the same.

This is even more confusing to me. http://rig-talk.com/forum/viewtopic.php?f=14&t=24026 where Olaf is stating that the Herbert is coming now with power tubes from "Svetlana =C= EL34s" and I have the original (new sets) of Ruby EL34B-STRs in mine. Either way, I like what I hear and that’s the name of the game and the fun of it all.

 

[Peter Diezel]

Don´t want to confuse, but currently we
use E34L-JJ and I want to get E34LS Teslovak
next year.

The JJ´s have some extra punch and a good
cut through.

 

[King Crimson]

Don´t want to confuse, but currently we
use E34L-JJ and I want to get E34LS Teslovak
next year.

The JJ´s have some extra punch and a good
cut through.

Oh man...

Peter, just through out a placebo tube and let it be done!

 

[BigR]

Don´t want to confuse, but currently we
use E34L-JJ and I want to get E34LS Teslovak
next year.

The JJ´s have some extra punch and a good
cut through.

Oh man...

Peter, just through out a placebo tube and let it be done!

+1. I can't imagine any decent tube making Herbert sound less than stellar. But with the external bias points (thank you for that, Peter),and the 2 matched quads of JJ e34l's I have laying around, I'm feeling compelled to do a bit of experimenting
Now if only my Ecstasy were as easy to bias.

 

[Peter Diezel]

Don´t want to confuse, but currently we
use E34L-JJ and I want to get E34LS Teslovak
next year.

The JJ´s have some extra punch and a good
cut through.

Oh man...

Peter, just through out a placebo tube and let it be done!

EL34 Diezel PCO ?

 

[King Crimson]

Thanks, King Crimson. I think they probably are relabelled Rubys. The side of the tube says TAD, and EL34B-STR below that (i forgot the "B" on my earlier post). The base of the tube is brown/orange, and there is a sticker on each tube base that says "Tube Amp Doctor Selected 3".

Most likely they are. Also, Ruby is a very generic label. A Ruby tube could be Chinese, Russian or other.

I'm not a fan of JJ preamp tubes in my Herbert, but the JJ power tubes (both the 6L6 & EL34 types) are really nice in my Herbert.

 

[Sam Laming]

What is redplating?

 

[BigR]

What is redplating?

It's when one of the power tubes glows bright orange, kinda looks like all the metal structure inside the tube is on fire. Much, much brigther than the normal glow you get from tubes. I'm not sure what causes it, but you'll know it if you ever see it.

 

[Sam Laming]

I see, kinda looks like 'overburning' then? Cheers for that. Anyone know more about it?/How it's caused?/Purely faulty tubes?

 

[BigR]

I see, kinda looks like 'overburning' then? Cheers for that. Anyone know more about it?/How it's caused?/Purely faulty tubes?

Yeah, overburning would definately describe it, as would melting . Not sure what all causes it, though faulty tubes is one possibility. Tube #1 on my Herbert redplated the one time, and hasn't since (knock on wood).