New power tubes (5:25)

[J.J]

After 11 months of daily use, many jams and a number of gigs, both volume and tone seemed to be lacking. Since I didn't have a spare set, I thought it would be good to have a spare set, even if there was nothing wrong with the original tubes. Since it is a little dificult to get tubes matched to Mesa specs in Auastralia (except Mesa tubes) I just went to my dealer and got the Mesa tubes.

The new tubes are quite a bit brighter and the mix cutting tone is definately back. I'd eventually like to try some JJ or other tubes in the 5:25, but I am happy enough with the Mesa/Sovtecs for now. Just goes to show that old tubes can loose their tone. Volume still seems down, but I suspect the amp may have a fault that is limiting it's output.

I also have the Tungsol reissues in V1 and V2. That change was done within the first month and made a big improvement over the stock tubes. I have periodically swapped back the Mesa 12ax7s, but it isn't long before the Tungsols go back in. The Tungsols do seem to have a bit less gain, but that suits me fine.

What are others experiences with swapping tubes ?

 

[StevenL]

I've gone through a few sets of power tubes since I've have my 5:25. You can definitely tell when they lose their punch. Seems like they last about 6-8 months and one day you just think....I don't like the sound of this amp any more, it's dull and lifeless. The new ones restore the mojo immediately. Your ears just go ahhhh . Been using some Groove Tubes #3s somebody gave me (6 of em). I have to order some more pretty soon. May get the gold series medium GTs to try out. I think Groove Tubes are all that Mesa will officially sanction for some reason.

I'm thinking of retubing the preamp soon. Since preamp tubes last so long, I may try to find a couple of nice NOS tubes for V2 & V1 and get cheaper new productions for the others. Seems, since the V2 & V1 have the most effect on the sound, you'd want the best and quietest tubes there. Hoping to get rid of some hiss on retubing. And if the preamp retube makes the difference most everyone says, I'm gonna be a happy camper since it sounds great anyway.

Most folks seem pretty happy with the Doug's Tubes set with the Tungsol in V2.

 

[J.J]

StevenL, your description of what old tubes sounds like matches my experience very well.

As far as I know Groove tubes are Sovtek which are the same type as Mesa ones. I had a pair of Groove tubes (EL84) from another amp and the contruction is identical. I think that has a lot to do with why Mesa don't mind us using Groove tubes in these amps. The difference in spec between Sovtec tubes is most likely a lot less than between other brands. Also, the Sovtek tubes are known to cope with the rather high voltages the Express runs.

Have fun with your preamp retube...