need biasing or not?

hi folks,
i've got a 1963 Calbest 8211 amplifier. for each channel, there are 2 6BQ5 power tubes and 3 12AX7 preamp tubes. they share a 5U4G rectifier tube. i know that when i replaced the power tubes, they had to be properly biased. I recently had a preamp tube go bad. do i have to have the replacement biased or can i just pop in another 12AX7?
You list your power amp but ask a question about bias for your preamp. Typically, tubed preamps do not require rebiasing when changing tubes, but there are exceptions. What does your manual say?
power amp and preamp are integrated. i don't have a manual but thanks for the info! that's what i was hoping to hear!