@bfreedma
There are many tube sellers on the internet (new and used tubes) so we cannot blanketly say you can buy from anyone and we'll fix the amp for free if a "compatible" tube caused damage to it.
Again, the warranty is against manufacturing defects. That said, in most cases we have taken care of the customer. In fact, our warranty is transferable from the original purchaser. I have worked for Woo for over 4 yrs. and we have not turned away a single customer when they need product support or repair.