Tube question/problem?

Ryan Freeland · 08-06-2006, 10:06 AM

I was checking out my power tubes yesterday while the amp was running, and one of them was A LOT more blue than the other. The amp works fine, I just want to know if this could possibly be the sign of a dying tube?

**Rainer.** · 08-06-2006, 10:31 AM

Or could be improper biasing.

Ryan Freeland · 08-06-2006, 10:39 AM

Quote:

Originally Posted by Rainer.

Or could be improper biasing.

Carvin biases their amps cold when you come out of the factory. It's still the stock tubes, so they have never been rebiased.

**Rainer.** · 08-06-2006, 10:47 AM

Well, maybe that tube is feeling upset with you today.

**thesteve** · 08-06-2006, 12:40 PM

Blue and orange is good...

red is bad...

I honestly wouldn't worry too much about it. It could be a failing tube, but usually power tubes fail gradually, not suddenly, so you'll hear it going before it fails.

Ryan Freeland · 08-06-2006, 12:47 PM

Quote:

Originally Posted by thesteve

Blue and orange is good...

red is bad...

I honestly wouldn't worry too much about it. It could be a failing tube, but usually power tubes fail gradually, not suddenly, so you'll hear it going before it fails.

Okay, just checking. The one with the blue has LOTS of it. The other has mostly orangeish-yellow, and jut a bit of blue. It's up for a retube within a few months anway.

**thesteve** · 08-06-2006, 12:51 PM

Quote:

Originally Posted by Building429_Boy

Okay, just checking. The one with the blue has LOTS of it. The other has mostly orangeish-yellow, and jut a bit of blue. It's up for a retube within a few months anway.

why is it up for retube in a few months? just for fun?

**Rainer.** · 08-06-2006, 01:03 PM

Of course, retubing is some serious minutes of unbridled fun and games!

Ryan Freeland · 08-06-2006, 01:07 PM

Quote:

Originally Posted by thesteve

why is it up for retube in a few months? just for fun?

The amp is 2.5 years old, with stock tubes. And I guess it's fun too.

I'll probably be going for some EH 12AX7's and JJ 6L6's possibly.

**Rainer.** · 08-06-2006, 01:11 PM

No, actually, it's not that fun. I remember my Marshall Valvestate... only had one tube, but that thing was a pain to change.

**thesteve** · 08-06-2006, 01:17 PM

Quote:

Originally Posted by Building429_Boy

The amp is 2.5 years old, with stock tubes. And I guess it's fun too.

I'll probably be going for some EH 12AX7's and JJ 6L6's possibly.

according to how heavily it's been used, it mgiht not need it, especially since you said it's biased cold from the factory.

still, at some point you may as well do it just to get a spare set if you didn't really need it. I believe that www.eurotubes.com sells complete matched sets of tubes for the MTS.

Ryan Freeland · 08-06-2006, 01:42 PM

Quote:

Originally Posted by thesteve

according to how heavily it's been used, it mgiht not need it, especially since you said it's biased cold from the factory.

still, at some point you may as well do it just to get a spare set if you didn't really need it. I believe that www.eurotubes.com sells complete matched sets of tubes for the MTS.

Been there. But, I'll probably order through www.tubestore.com.

For preamp tubes, I'll put EH12ax7's in the V1, V2, V3 sockets. An EH12at7 in the V4 socket (for reverb) and a balanced EH12ax7 in V5, which is the phase inverter.

And powers, 4 JJ 6L6GC's.

SDA_Bluesman62 · 08-06-2006, 06:07 PM

Thanks for the links to places to buy tubes, fellas.