6 hours of music playing, I paused music every hour to listen for ticking. Nothing, all silent. Fingers crossed I solved it.
Last night another listening session running 8.5 hours, checked every hour and NO ticking. Getting optimistic that the issue is resolved. So my findings in older equipment that produces a lot of heat the 5w wirewound resistors seem to get affected and although they measure with a DMM the correct ohm rating when they are hot they produce some ticking within the circuit. Replacing them and carefully checking your solder joints seems to solve this.