Nope. 45 year-old Traynor Bassmaster always works all the time. Even with only one power tube for the entire gig after the other fell out and shattered in the back of the car without me noticing. Was it extra distorted? Yes, but that's good! I even briefly considered keeping it that way, but thought better of it and stuffed in some old el34 I found at the bottom of a box. Biasing? Nonsense! That was 10 years ago and it's still going...
Guitar got two half stacks as well.