This does not indicate a problem with either the amp or preamp. It is generally recommended to power up a system from source electronics to power amp (power amp on last.) When you power down you do the reverse, by turning the power amp off first and then the preamp. This avoids any transients from the power up sequence of the preamp being sent to the power amp. You should wait until the preamp comes out of its mute or standby state if it has one before powering up the amp.
7 responses Add your response