Can anyone help me identify this tube?

[chillytouch]

Re: Can anyone help me identify this tube?

You're going to have to have the amp biased with the new power tubes by a qualified tech unless you know what you're doing.
I get the impression you don't know how to bias an amp.
And its not for beginners.

And if you're doing it yourself you wanna keep an eye on the quad especially the socket that had the bad tube for redplating or any other anomalies when you power up the amp being ready to shut it off if you have problems.

I'm going to see if the tech will show me. The stealth has the bias probes/control on the back I believe so you don't actually need to open up the chassis, so maybe he can show me how to do it on my amp since it seems like the risk of electric shock would be less since I don't need to actually open it up. But, that's just guessing. Feels bad though, get it, play for 1 second and realize there's an issue and then have to leave it at a tech for 3 weeks to get it biased, great.

 

[dystrust]

Re: Can anyone help me identify this tube?

You're going to have to have the amp biased with the new power tubes by a qualified tech unless you know what you're doing.
I get the impression you don't know how to bias an amp.
And its not for beginners.

And if you're doing it yourself you wanna keep an eye on the quad especially the socket that had the bad tube for redplating or any other anomalies when you power up the amp being ready to shut it off if you have problems.

That amp has external bias points, so it shouldn't be super difficult to bias if the OP has a decent multi-meter. It'll definitely be a lot more safe than biasing a typical tube amp.

 

[chillytouch]

Re: Can anyone help me identify this tube?

That amp has external bias points, so it shouldn't be super difficult to bias if the OP has a decent multi-meter. It'll definitely be a lot more safe than biasing a typical tube amp.

Yeah, I will call my tech, but at the very least maybe I can at least use the external bias point to check what it is when I swap out the tubes.

 

[Gtrjunior]

Re: Can anyone help me identify this tube?

Yeah, I will call my tech, but at the very least maybe I can at least use the external bias point to check what it is when I swap out the tubes.

You could search a YouTube vid. I’m sure there is a tutorial out there.

 

[chillytouch]

Re: Can anyone help me identify this tube?

You could search a YouTube vid. I’m sure there is a tutorial out there.

Yeah, I think I could actually bias it myself with the external points after all the research I did last night.

The only 2 questions I have left which I guess I could ask a tech are:

#1 theres only 1 external bias point (1 positive, 1 negative terminal, and the pot), but there's 4 tubes, all the videos I searched had a positive terminal for each tube. Will mine read a total of all 4 tubes, or just a random single tube in the lineup?

#2 What i should be biasing it to. I don't have the service manual so idk what the 100s is supposed to be stock. I saw a few people online saying stock was biased at anywhere from 25-30 and then people wanted them hotter. I want it stock or on the colder side, so maybe i go for 25-28.

 

[Gtrjunior]

Re: Can anyone help me identify this tube?

Yeah, I think I could actually bias it myself with the external points after all the research I did last night.

The only 2 questions I have left which I guess I could ask a tech are:

#1 theres only 1 external bias point (1 positive, 1 negative terminal, and the pot), but there's 4 tubes, all the videos I searched had a positive terminal for each tube. Will mine read a total of all 4 tubes, or just a random single tube in the lineup?

#2 What i should be biasing it to. I don't have the service manual so idk what the 100s is supposed to be stock. I saw a few people online saying stock was biased at anywhere from 25-30 and then people wanted them hotter. I want it stock or on the colder side, so maybe i go for 25-28.

So I’m not 100% familiar with your particular amp but amps that have only 1 bias pot would typically have the bias set at an “average” for all tube. Unless there are separate pots for each tube there is no way to set the bias individually.

There is a formula you need in order to set the bias.
You need to determine the plate voltage, then use the formula to determine what your bias setting should be.

 

[JMP/HBE]

Re: Can anyone help me identify this tube?

Yeah, I think I could actually bias it myself with the external points after all the research I did last night.

The only 2 questions I have left which I guess I could ask a tech are:

#1 theres only 1 external bias point (1 positive, 1 negative terminal, and the pot), but there's 4 tubes, all the videos I searched had a positive terminal for each tube. Will mine read a total of all 4 tubes, or just a random single tube in the lineup?

#2 What i should be biasing it to. I don't have the service manual so idk what the 100s is supposed to be stock. I saw a few people online saying stock was biased at anywhere from 25-30 and then people wanted them hotter. I want it stock or on the colder side, so maybe i go for 25-28.

Bias is set in relation to plate dissapation & plate voltage [realtime], not some random number. The "bias terminal" on your amp is likely connected to just one power socket via a resistor therefore you would be measuring millivolts as opposed to milliamps.
Most 100 watt amps with bias points have them hooked in pairs.
And you really need to know the current draw of each power tube and also bias in pairs with an accurate "bias probe'.
Like i said its not an entry level kinda thing.
And you can wing it but there's a price to pay for that & you can expect more blown tubes & costly repairs.
Like i also said you have no idea why it blew a tube in the first place.
Tube failure is but a symptom of a larger problem.
You don't even know if it was properly biased in the first place.
You don't even know if you have melted grid resistors or other burnt up components.
If it arched and has carbon all over the board carbon is conductive and thats a clusterfeck waiting to happen.
Did your amp blow an HT fuse ?
If it did was the fuse replaced with the correct value replacement ?
Experience matters working on Electronics just like anything else in life.