amp is taken it`s time to power up

hi guys
i have 2 quicksilver v 4` gets to the right biased level very quickly,the other takes an additional 15 minutes to bias up level.this just started to happen recently.any thoughts?
thanks very much
Don't know Quicksilver designs, but what I'd guess is that if they have a slow start feature during which the amp is muted for the first 3 to 5 minutes, one of the amps is coming up too quickly OR, more likely, the other is just coming up too slowly. 15 minutes seems like a long time to me. But you probably figured that out already. I'd call Mike Sanders and ask him.