triple rectifier tube questions

[theearthisourfeast]

i have a new to me triple rec that i've been playing for the last month or so. While i love it, I can't help but feel that it is just a bit muffled and kind of dirty sounding. The previous owner replaced the tubes 2 years ago with stock mesa tubes and said they did not have much playing time on them, but i feel like maybe swapping them out would bring it to life a little more. Short of swapping them out is there a way to easily test the tubes to see if they are getting towards the end of their life? Also, i was looking at the Mesa High Gain Pre Option with 6v6s at eurotubes here towards the bottom of the page: https://ssl.eurotubes.com/cart/index.php?page=view_products&category_id=6&sub_category_id=74
Anyone ever try this out? Thanks for any input.

 

[Silverwulf]

I like the high gain pre's, but I'm only so-so on the 6V6's.

 

[theearthisourfeast]

why not the 6v6's? just curious as tubes are new to me and if i'm gonna retube it i'd like to try something different than stock, but i'm beginning to get lost in all the possibilities. For what it's worth, I play mostly metal, and for the time being in my living room so getting the breakup at a lower volume appeals to me at this point. I guess i'm looking for a sound that has a serious low end for slow heavy stuff but stays clear and doesnt get muddy. sometimes play with fuzz pedals, and most of the time lately with some OD with gain all the way down. I also would like a nice warm clean tone. If anyone can point me in the right direction and explain what they love about the tubes they use, i would be grateful...