Randalljax
Axe-Master
Many metal guys do the cold biased tubesTo add some more context, and since I know you're a fan of the 5150 among others: The 5150 especially was fixed bias from the factory and could only be adjusted if you modded it in, so it does make sense that your real 5150 would be biased colder than the "how a tech would set it" bias Cliff chose. Mesa amps are the same.
Kyle from KSR is another that told me the ship cold to increase tube life and because a lot of customers want the tightness but if you want a warmer sound with a little give for
hard rock he recommends a hotter bias