anXorchestratedXfailure said:
How is a tubes' hardness related to it's sound? Is the lower the number the cleaner? How does this work?
You're talking about the Groove Tubes' rating scale. There are three main categories within power tube grading that most people often use.
The power tubes that are labeled with the numbers 1, 2 and 3 are the cooler tubes.
The power tubes that are labeled with the numbers 4, 5, 6 and 7 are the Middle Ground tubes, which are often refered to as Mesa Spec. The power tubes Mesa sells actually fall within GT's Hardness scale of 4, 5 and 6.
The power tubes that are labeled with the numbers 8, 9 and 10 are the Hot tubes.
As far as the tonal differences, well it depends on the circuit (amp) and how they are biased.
The cooler tubes tend to have more touch sensetivity, they sound fuller and will break up much quicker. The cathode current draw (bias current) will be less than the Hot and Middle Ground tubes.
The Hot tubes will have way less touch sensetivity, will sound very compressed and will not break up as soon as the cooler stuff or the Middle Ground/Mesa Spec. tubes. The cathode current draw will be much higher than the Cooler tubes and will still be hotter than the Middle Ground tubes.
The Middle Ground/Mesa Spec. tubes have the best blend of touch sensetivity and headroom. They will not be as compressed as the Hot tubes, but will have a little more compression than the cooler ones. The cathode current draw will be higher than the Cooler tubes and will be lower than the Hot tubes.
Another note in regard to touch sensetivity and the feel of the amp... If you're using an amplifer that is biased up cold or is biased up too hot, you really won't notice any changes in touch sensetivity. The only thing you will really notice is the differences in the amount of headroom. The Mesa Rectos are prime candidates in this area. The ENGL Powerballs that I've owned were prime candidates in this area.
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