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[gadgetfreak]

Hello new to board but not to Mesa. I just picked up another express 5:50, I owned one when they first came out and didn't have it long. I found some chewing gum stuffed up inside near the powertubes and the store didn't have another one so I returned it and being impulsive I bought something else, always wanted another one so here we are

I just picked up this very mint express 5:50, with cover,manual,tags,original receipt signed over to me, Very good deal on the amp and I couldn't be happier. I haven't gotten out of playing clean with it yet, I am so impressed with the cleans and the usable reverb. I own many fenders and I just cannot believe how under rated mesa's are for having great verb and clean's. I know you guys all know but I bet if you said what's best clean tone amp, you know what 99percent of folks are going to say.

So here is where I could use some advice, I understand the amp doesn't need to be bias'd and fortunely for me my amp has new power tubes from mesa and I have the old ones for backup. The original owner told me I have to use Mesa tubes, I have never heard of this before. Why can't I use other tubes? I figure they probably match and set there tubes to a certain spec but if I was to tell the tube vendor my amp I'm sure they could find something that would work. Like I said I have new tubes in there but really would like freedom to choose my tone if possible.

Second the pre-amp tubes are original, the amp is from 08. You never know the difference in tone until you change them and say wow that sounds great or not so great. I have quiet a supply of 12ax7's lying around from always tone chasing with other amps and would like to try some different flavors in my mesa. I take it there are no issue's with swapping pre amp tubes correct? I have some tungsols, mullards, NOS Mullards and Rca's and I have a bunch of JJ's,EH,Sovtek lps and Ruby's and GT. Basically have em all kicking around.. I haven't really gotten into the manual yet but I read somewhere that the clean channel position is actually V2 and not V1, is this correct? I heard it was backwards or something. Where are you guys finding the best tonal changes from stock tubes, I mean what positions? I usually change out v1 and v2 and i like to put a nice SovtekLPs in phase inverter. I have some 12at7's that are NOS Mullards for Reverb drivers, I don't know if in this amp they make a big difference, This is why I am asking.

Sorry for the long post but I am so stoked to own a Mesa again and I play blues and rock mainly, Just looking to get the most out of my new to me amp. I don't know what mesa uses for 12ax7's and just thought I would ask first, especially about the powertubes and that whole you have to use Mesa valves or else statement I read. Thanks and look forward to posting some tones eventually

 

[Krek13]

you don't have to use mesa tubes, you can use any brand you want but you need to have them tested so that they match the bias of the express 5:50...online stores like eurotubes, dougs' tubes etc. can do that for you...I'm using JJs in my express which I ordered from eurotubes cca half a year ago and I have no problem..mesa tubes are already tested so that they match the bias range of mesa amps...

there is also a possibility of a simple mod to your amp so that you can adjust the bias itself, any amp tech can do that...I'm not a tech but if I remeber correctly the whole mod consists of putting two resistors in the right place

ofcourse, you can change preamp tubes right away because there's no need to bias them...

in your manual there is a scheme of tube sockets and the function of every socket is written...

HTH and sorry for my english, I'm not a native speaker :mrgreen:

 

[gadgetfreak]

Thanks for the reply and your English is fine, So tell me are these specs for the tubes written out somewhere or will the vendors know automatically which tubes will work? So say I wanted to try some SED winged=c='s do I just let them know there for a Mesa express 50? I mean how do they know from there shop what my amp is set at currently? Only thing I don't like about the amp is no bias pot, I am used to bias'g my own amps. I dig that I don't have to but I want to make sure the tubes I'm buying are going to run at the correct dissipation and not run cold to play it safe. I will have to look into having a tech check out if an external bias pot can be installed. Anyone else ever do this or is current design for than efficient?

 

[Krek13]

Thanks for the reply and your English is fine, So tell me are these specs for the tubes written out somewhere or will the vendors know automatically which tubes will work? So say I wanted to try some SED winged=c='s do I just let them know there for a Mesa express 50? I mean how do they know from there shop what my amp is set at currently?

guys from eurotubes test the models of amps and measure the current...I presume other shops do that aswell or they just get the right information...mesa biases their amps cold...

Only thing I don't like about the amp is no bias pot, I am used to bias'g my own amps. I dig that I don't have to but I want to make sure the tubes I'm buying are going to run at the correct dissipation and not run cold to play it safe. I will have to look into having a tech check out if an external bias pot can be installed. Anyone else ever do this or is current design for than efficient?

you can have a bias pot installed and it's a simple mod and it works very well...check the rest of the forum for more information if you want to, there's been some talk in more popular subforums (recto, mark etc...)...or just google it...but any good tech will know how to do that...you should have that mod made if you like to bias your amp

enjoy

 

[Don]

It's good to see you here!

The PI/driver tube on that amp (V5) is new and I replaced V2. I kept the tubes all Mesa because they sound fine and I wanted to stay within that warranty. That's not to say that it can't sound better. There are tube combinations that others have sworn by to make the amp sound better and run quieter.

I didn't mean to imply that other power tubes can't be used. There are quite a few vendors who can sell you Mesa compatible tubes (though not Mesa warranty compatible).

As far as adding a bias pot is concerned, I think that would be a good mod, though I'd wait until the warranty was over.

Enjoy the amp!

 

[gadgetfreak]

Hey Don small world!!!... it's all good, I absolutely love the amp and haven't really strayed from the clean channel, it's so lush and perfect for my sound. I'm just picking peoples brains that have had these amps awhile and to see what they think.

I won't do any mods until warranty is over obviously but I do know with tube amps, if they tend to run the bias colder, you can yeild better tone by bringing it warmer. Good to see you on here, and I am so freakin happy with this purchase you don't even know, Thanks again.

To all Don is the guy I bought amp from and is a straight shooter and a very fair man to deal with, don't have any hesitation.

Thanks for replies.

 

[Newysurfer]

Hey Don small world!!!... it's all good, I absolutely love the amp and haven't really strayed from the clean channel, it's so lush and perfect for my sound. I'm just picking peoples brains that have had these amps awhile and to see what they think.

I won't do any mods until warranty is over obviously but I do know with tube amps, if they tend to run the bias colder, you can yeild better tone by bringing it warmer. Good to see you on here, and I am so freakin happy with this purchase you don't even know, Thanks again.

To all Don is the guy I bought amp from and is a straight shooter and a very fair man to deal with, don't have any hesitation.

Thanks for replies.

There's been lots of tube talk here over the years hehe
Most agree - the stock chinese Mesa tubes are ok - nothing special but.
If you want significantly better, smoother tones & higher gain on the burn channel with far less noise then do a full tube swap for around $100 with the mixed tube set from http://www.dougstubes.com. He only sells matched power tubes & no bias required.
I'll never go back to Mesa tubes but still have them as backups, or if I ever have to use the warranty :mrgreen:

I don't see any need for a bias switch/dial on this amp at all. Try different tubes before you play with that