Moved my ZP100 to now work in a 2 room setup with a Parallel A/B Switch and four 8 ohm speakers.
Everything seemed to work fine and the A/B switch was doing its job nicely but at some point I noticed the right channel was no longer working in either room. I swapped the connections at the back of the Sonos and the right hand speakers were OK so it must be the Sonos right channel had failed !!
Turning off and back on at the wall did not bring the right channel back to life. I thought I had blown it somehow.
I checked the A/B switch resistances seen by the Sonos with a cheap multi-meter. Set to A pair the resistance was about 5.5 ohm (prob not expecting to see 8 here), the B pair was the same and the A/B pair did reduce the resistance to about 3 something, so at least no shorts and the wiring looks OK.
Anyway, leaving the ZP100 off for about 6 hours and it was OK again.
I thought maybe I can't switch from an 8 ohm load to a 4 ohm load whilst it is switched on, maybe I have to pause the music first. I tried this and it seemed to be OK if I paused the music before switching over. But another time when I tried this method the right channel stopped again.
So, any ideas?
(1) Is it OK to change the load from 8 ohm to 4 ohm on the fly with an A/B switch?
(2) Could my A/B switch be causing a short as I switch from A -> to B -> A+B (surely not)
(3) Could the ZP100 be cutting a channel when it sees a brief open circuit between A/B changes?
(4) Should I be pausing the music before changing the load? (worked the once I think)
(5) Am I blowing a resettable fuse each time I try this, should I stop experimenting immediately before I perm blow it?