Solid state bias adjustment.

I've recently replaced the output transistors and caps on a Denon poa-2400 that had a blown channel.
It works and sounds fine. It does not run hot no matter what I throw at it.
How critical to sound and component longivity is the bias adjustment?
According to the service manual I would need to purchase a function generator at minumum to set it.
All my other equipment is Denon and I see broken units for sale all the time.
Thanks for any help or information.