can you replace just one tube?...

[moonshineboogie]

one of my tubes is redplating in my RK1, i want to replace it but i don't know if i have to replace all of them or if i can just get away with replacing the bad one, and if my amp should get rebiased. i've only been on this forum for a few hours now and i think i'm the king of stupid questions.

any help would be appreciated, thanks.

 

[Boogiebabies]

Depending on how old they are, if the two inner tubes or outer tubes are relatively new, you can replace either of the two banks. If they are all old, change all the power tubes. As tubes age, they change in plate current and the amount of bias they draw. You are looking for trouble replacing one tube. If the rectifier tubes are bad, replace them both as well. They work together just like the inner pair and outer pair of your power tubes.

Red plates are usually and internal short that causes the tube to pull way too much bias and may be running too high of a voltage. If it did not blow your fuse, you got to it in time, because a blown tube can take out resistors in the bias supply, screen grids and if they go too long without the fuse blowing, they can take your output transformer.

Make sure you have the correct rated Slo-Blo fuse as well.

 

[moonshineboogie]

i do have the proper fuse. im hoping that the redplating is due to the tube(el34) being bad. i dont know how to check for an internal short. i use my amp 2 rock loud, i figure thats why they made it 150watts. im hoping that playing loud isnt what caused this because that would make me think that mesa is weak and i dont want 2 feel this way

 

[oyster]

dude, don't worry about that - these amps are MADE to PLAY LOUD! 8)

 

[mrdylan]

Mine only sounds good loud I can't/don't even play it at home.

Tubes are almost 2 years old now too.

 

[moonshineboogie]

feewww, thats a relief. i has hoping so. im gonna re tube the whole thing and hope thats that! thanks all