Quote Originally Posted by Raj J
no problem at all for those of you who want to retain the same output tubes as recommended by the manufacturer, keep what you have; I am sure you are enjoying your music!
Thanks for the heads up. I'll stay tuned to what Luke Manley does. The tube draws 100-300 mA more filament current than a 6550. The third generation MB-450 was in use by a number of manufacturers at recent shows and I'm leery of a more "tubey sound" as reported by others: Another review.

rw