Naim 135s - noise when switching on

samedi 19 mars 2016

I have an active system using Naim 135s. The 135s were all serviced about 7 years ago and the system sounds fine, but just recently one of the 135s connected to the bass/mid has started making a much louder noise through the speaker when switching it on than the other.

I have swapped the amps over and the noise moves so it is the amp. It still sounds good, but is it the start of a problem?