Tube swap in Express 5:50

[guitarchris76]

I was wondering if it is possible to swap the tubes in my Express 5:50 for EL84's. Any help would be appreciated.

 

[Newysurfer]

Can't you just remove the metal grill and unscrew them. Check it out. THere's stuff in the manual about it

 

[cant play pool with a rop]

I useed to have a 5:50 and don't recall being able to switch out different power tubes other then a different brand 6L6. If its not mentioned in the manual don't do it. EL84S are for the 5:25

 

[NuSkoolTone]

If you used Yellow jackets you probably could for EL84's.

If you mean EL34's, probably not without modifications to the amp for biasing.

 

[scottkahn]

No. EL84s are too small. You'd have to use EL34, but the 5:50 isn't made to work with those either. While many more-costly Mesa/Boogie amps are made with BIAS switches to configure them for use with either 6L6 or EL34 tubes, there is no such design characteristic in the Express -- it is a fixed bias amp made only for use with 6L6 tubes.

 

[vermillion]

So..

6L6 to 6L6 = yes (duh!!)

6L6 to EL34 = no (oh well)

6L6 to EL84 = yes with THD Yellowjacket Converter (cool!! someone try it and let us know!!, I'm curious)

6L6 to 6V6 = ??? (The Lonestar Classic manual says you can use 6V6 tubes if you use 4 tubes and an 8 ohm speaker in the 4 ohm jack, but theres no tweed power setting in the express 5:50) I won't be trying this unless I hear from Mesa that I can.

6L6 to 5881 = ??? maybe? (plate voltage is the same?)

6L6 to 6L6GC = my guess is no. (because of plate voltage)

6L6 to KT66 = my guess is no. (because of plate voltage)

So, has anyone used any other 6L6 tubes? (non-mesa branded) I don't know enough about tubes to make any recommendations.

 

[vermillion]

okay, i did some more reading..
6L6GC are the "modern" design 6L6 (and I uh looked in my amp too...)