Replaced my ruby 6l6s with Mesa 6l6s....i am disappoint

not that great. Not bad by any means but the tone is really different. I went from a thick and ultra compressed sound to a pretty thin sounding midrangy sound.


pretty disappointed, I've had the tubes less than a month and I already want to replace them. Anyone else have similar experience with this? I tried EQing differently as well, no dice.

Mesa str 440 and Ruby 6l6gc supose to be same tube...Both are rebranded Chinesse Sino/Shuguang tubes...Only difference would be bias point so one set would run hotter than other quad...

I think what people dont realize is that tubes of the same brand and type can have different plate values which effect the bias of the amp, similar to how having an adjustable bias works but its not adjustable. I find if you get the same brand of tube with a lower plate value, it is going to give you less headroom and early breakup. Higher plate value will get you more headroom, later breakup - but run hotter and dissipate faster.

When buying from the tubedepot or tubestore, pay attention to those perfect bias numbers. If you get a number that feels thin, you could ask if they have a value 3-5 lower. For example, you find 19's thin and you want more breakup, try 16 or 15s. Again, this is just an example as I cant remember what the 6L6 values for Mesa are but the store should know the max "safe" bias' for the amp.

I am going to order online next time. My local place only has mismatched tubes that will require a bias, unless it's just BS they fed me to sell me the 'mesa' brand tubes. I really wanted to try something different to experiment but the guy told me that I would need to bias my amp (despite it having a fixed bias) if I went with anything other than mesa.


next time I am ordering online and asking the place what they recommend.

Mismatched in what sense? As long as the Mesa 6L6 pairs are colour coded the same, you'll be fine...