I had to pull my power tubes today. I put stock Mesas in it. It didn't sound very good compared to the Rubys. I looked at the Rubys and noticed the test PC was 38ma. So, I've been running the power section much warmer than I thought I was, while using Bold and Tube.
I could be wrong, but Mesa 6L6 are picked to be in the low 20s. To compensate with them, I set it to EL34, Spongy, Silicon. It got close to where the Rubys were, but not quite. When in a normal 6L6 setting, the Ruby could crunch a little and then clean up quickly. The Mesa are not cleaning up as much on EL34, but get closer if I put it on tube rectifier. I plan on getting another set of Rubys and going back to a normal setting.
To contrast the sound in 6L6 settings, I'd say the Mesas have a relative high-mid emphasis and a big low end. Ruby have a strong low-mid emphasis and tapered treble. I think this is why I've been using more treble than some of you.
I was wondering if anyone had tried a warmer set of Tung Sol STR tubes?