6l6 tube reading

[Slyfox]

Greetings,

What Ma reading should I get from the power tubes on a mesa Express 5 50?

I am getting 60ma on two different sets which seems high. As well, the volume even in 5 watt mode seems excessive and tone control sensitivity is high. Cant seem to dial in a smooth warm sound where as I've heard my amp sound much better literally hours before where 5 watt was reasonable and everything was smooth, warm and buttery.

Does this sound like somehow the bias is off or sign of some other problem?

I'm at my wits end swapping cables and rolling preamp tubes.

 

[Slyfox]

I tested the same tube in a mesa roadster on 100 watt, bold, silicone diode and was getting 24ma which "amplifies" my theory the express is somehow running excessively hot and why the volume seems excessive on 5 watt and tone controls seems magnified and harsh.

 

[user 21540]

That's weird. According to Eurotubes they run most of their 6L6 stuff cold.

https://www.eurotubes.com/store/pc/mesa%20boogie%20amps.htm

Are you using Mesa Tubes in both amps?

 

[Slyfox]

Yes, mesa tubes in both. What would cause the amp to run intermittently really hot like that?

 

[user 21540]

Yes, mesa tubes in both. What would cause the amp to run intermittently really hot like that?

I'm not a tech -- just an avid user who does some of my own work. If you're in the US you should contact them as you are 'playing by the rules' and using their tubes:

https://store.mesaboogie.com/pages/contact-us.html

I have had my Rocket 44 running very hot in the past with a set of EL84s that were not in the right bias range but Mesa's tubes are meant to be plug and play. The only other thing I can think of is that you have some sort of component drift in your amp and it might need to be checked out by a tech.