Tube Issue - Need Help

[shredhead72]

Hey all,

This is my first issue with tubes and I'm not even sure if I have a problem. Last night I was doing some home recording and I heard this strange low hum coming from the amp. Most noticealby on channel 3. I felt like some "power" was drained from my tone, so I shut the amp and went to bed. This morning, it sounds kick *** again, but one of the outer most tubes is not lit. See picture below. Is that a dead tube (on the left) that I have to replace?

 

[bucketbot]

The left hand tube of the 5 is the rectifier. It looks like you have it switched out at present But of course the switch only selects tube or diode in the 45 watt position. Where do you have you power settings set?

 

[shredhead72]

I'm pentode, 45 watt on Mark IV setting.

 

[bucketbot]

I'm pentode, 45 watt on Mark IV setting.

I'm pretty sure that Channel 3 does not use the rectifier tube but uses the diodes all the time, hence no switch for it.
If the tube looks dead you could try changing it & see if it helps but if it's OK now maybe it was just one of those gremlins!!? :evil:

 

[MusicManJP6]

I'm pretty sure the Recto tube does not glow like the power tubes.

 

[fuzzgod]

I think JP6 is right about the non-glow...but I will double check mine later.

 

[Chester]

I'm pretty sure the Recto tube does not glow like the power tubes.

+1 No glow in mine

 

[shredhead72]

Awesome... thanks for following up guys. I just got a little paranoid after hearing that hum and looking back there to see no glow on the tube. I'm going to re-read the manual soon. It's still a lot of amp for me, but it has such awesome tones. Every time I turn a dial I get something awesome.