Mini Recto/verb power tube question

[Steve Naples]

Has anyone tried other EL84s in their amp? I have some TADs that I bought for spares to use in my Orange #4 head, and was wondering if I could drop them in?
I'm basically wondering if these amps are cathode biased, that way there is no need to check the bias levels.
I wish that I could get a schematic for these amps, seems Mesa is the only one that you cannot get a schematic for their amps. I have them for all the new Orange models, as I work on amps.

 

[elvis]

I assume you could get a schematic if you were an authorized repair dude, whatever that might entail.

I doubt they are cathode-biased. You will likely need to get tubes that have a similar DC bias point.

I have been running Mullard EL84 in my MR and RV25 with excellent results.

 

[Steve Naples]

I agree, not sure what that would entail.

Ok, I was afraid of that, I know the Orange is cathode biased.

That's what I was afraid of, I guess that I can get some from one of the tube shops online and just tell them they are for a Mesa. It would have been nice to run some NOS tubes.

I'll look into the Mullards, I haven't tried any yet.