Changing my power tubes

[taz_wynter]

hey all, this is a noob question but I was wondering what order I put my el34's into my mesa roadster?

theres 4 tubes spots and I put my tubes in this order

the first matched set into spots 1 and 2 left to right
then the second set in spot 3 and 4 left to right
played at a low volume okay, then when i cranked it up sounded like i blew the amp got very low volume and very fuzzy

is there a specific order i don't know about?
please help

 

[MrMarkIII]

No prob. You should put one matched pair in outer sockets 1 and 4. the other in 2 and 3. Like this: X Y Y X.
They should be "matched " by the color on the sticker on the base of the tube: Green (GRN), Grey (GRY), Red, Yellow, etc.
I believe there's a switch on the back to change between EL-34s and 6L6s?
Be sure to read Page 6 of the manual:
"NOTE: BIAS SETTING MUST MATCH TUBES IN USE. FAILURE TO DO SO WILL RESULT IN DAMAGE TO YOUR AMPLIFIER."
Hope this helps.

 

[taz_wynter]

Yeah that does help, it's exactly what i was looking for. now the question is by Bias setting you mean the switch that allows me to choose between EL34's and 6L6's right?

this is what i did wrong

I put one matched set in spot 1 and 2 then the other in 3 and 4

Tubes in spot 3 and 4 turned Red after 10 secs of playing so I shut the amp off and changed the tubes around, but the damage is most likely done right?

they were EL34's and I had the switch set to the EL34 setting

 

[Old BF Shred]

The switch for el34 or 6L6 is for type of tube used.
The bias is how the idle current of the tubes is determined. This is not adjustable in Mesa amps. You have to buy tubes that are in range for Mesa amps (i.e., Mesa tubes).

If one pair glows red, then they are either defective (unlikely that both in a pair would be) or they are the wrong biasing range for your amp (most likely).

Only Mesa tubes are guaranteed to be in this range right out of the box. Also Groove Tubes rated # 4, 5 or 6 are claimed to be in this range.
So if you bought another brand, they may not be right for your amp.
As to whether they are shot at this point, depends on how long they were glowing and how ruggedly they are made.....
anyone's guess at this point. Although it's unlikely they damaged your amp (yet), I would not try this again!
Get the right tubes...... 8)

Good luck!

 

[taz_wynter]

Yup I made sure to buy Mesa tubes - they are Mesa el34's
Going to bring it in since it's still on warranty and let them deal with it :lol:

 

[Old BF Shred]

Then you are definitely covered! 8)
Sounds like you got a rare defect!

At least you know they'll stand behind it. Good luck!