So was just playing my Einstein, volume disappeared, tube...

[Random Hero]

Glowing BRIGHT red. Quickly turned the standby on. Once I turned it back on from standby, it seemed to be performing normally. So I check the bias, and it's hovering around the late 90s

Set it back to somewhere in the mid 60s or so and all seems to be well again. I guess this tube is gonna be on the way out now?

 

[duesentrieb]

No spare tubes? Its a 50 Watter, right?

 

[Random Hero]

No spare tubes? Its a 50 Watter, right?

Yeah, it is. I do have some spares but it seems to be fine now?

 

[Random Hero]

Sorry to bump, but since I re-biased it, it's been working flawlessly? Is this usual? I suspect the tube is gonna die soon?

 

[HerbieTheRadDorklift]

Just while we're on the subject, how do you re-bias, and how do you check the bias?

 

[Random Hero]

Just while we're on the subject, how do you re-bias, and how do you check the bias?

With a multimeter, using the bias points at the back of the amp. Mark IVs don't have the option due to a fixed bias. I'm not sure about the Rebel or HT-5.

 

[HerbieTheRadDorklift]

Just while we're on the subject, how do you re-bias, and how do you check the bias?

With a multimeter, using the bias points at the back of the amp. Mark IVs don't have the option due to a fixed bias. I'm not sure about the Rebel or HT-5.

You know my amps, how sweet

Yeah, I like the Mesa has a fixed bias (a lot of people hate it though), I'll have to check on my other amps.

 

[nbarts]

Are you sure both power tubes are running?

 

[Random Hero]

Are you sure both power tubes are running?

It wouldn't work at all if one was dead, would it? Push-pull, right?

 

[nbarts]

I don't think so, but not sure. I know when the tube on my Uber blew, the fuse for the tube blew with it, but it kept working with 3 tubes.

Just look at them, if they light up, then they are running. I just find it hard to believe that a tube would go glowing bright the way you described it & then keep working after that.

 

[Random Hero]

I don't think so, but not sure. I know when the tube on my Uber blew, the fuse for the tube blew with it, but it kept working with 3 tubes.

Just look at them, if they light up, then they are running. I just find it hard to believe that a tube would go glowing bright the way you described it & then keep working after that.

Yeah, I've had tubes take fuses out before but this one has stood firm. And believe me, the tube was positively glowing! I guess these SEDs are pretty tough...