Mesa "STR440"? Need some help from you guru rollers!

J.J said:

From what I tell the Ruby 6L6 in the link is the same tube as the Mesa STR440 (Chinese Shuguang origin). I am not suprised you like them, I think they are a good sounding tube and very good value (Unless you get them from Mesa :wink: )

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yeah,i only have one issue, but can't figure out if it's amp related, or tube related. after about 3 hours of constant play at gig volume, my amp starts to get pretty mushy in a way i dont like (i think due to the heat)....its hard to explain...it doesn't sound as big and boisterous, rather, less focused and ....harder to play.

not a huge issue, and not one i'd likely attribute to THOSE tubes in particular, but moreso, like i said, an amp issue.

those rubys suit me fine for my needs though. and are a tremendous value.

I'd be betting on something in the amp. Capacitors can suddenly become leaky. I had one amp that would red plate after about 40 minutes. The amp would test just fine on the bench. It took years (not that I worked on it all that hard) to figure out that one of the coupling caps would blead off the bias votage, but only when hot causing the red plates.

One thing you can do is add a cooling fan, if that works then you know you have a heat related issue.

What kind of amp is the one in question ?

The =C= are really starting to take on a new color.

I am leaning towards them now.

I will keep listening and also in the mix is the **** unity gain thing so I have to get that straitened out and then all things being equal I can really judge the tone.

It could be a minor thing, but are the two sets of valves of the same bias rating???