cold, bright, empty, dark , hollow, unpleasent, sceptic dead sound, I ve tried this with various amps. Great colour with Engl, Peavey, Mesa amps. Quite cold and unpersonal touch when used with more clasic amps like VOX, Fender, .....
This walve has its own metal armour shielding around , ao its well suitable for big heads with big Watts as well :)
For me ? Tung Sol products fits better my needs. More colour, more worm, more thick......iven in dropped B ;)