wrote:



" ** Hope you also tried a few on-off cycles to check out the new PTC. "

Umm, shouldn't that be NTC ?



** The device used in the smaller XLS602 model is a PTC - about 27mm diameter and blue in colour. Measures 6 ohms at room temp rising sharply to over 10kohms when hot. It is rated to stand 240VAC after tripping.

A normal inrush surge is too brief to heat it to the trip temp ( about 120C ) while a relay bridges the device well before the amp un-mutes, so it does not have to carry the amp's running current.

If there is a major fault somewhere at switch on, the relay never operates and the PTC trips limiting AC current to under 25mA.

I'm not sure if Arfa's model use a PTC or an NTC, but he seems to have used an NTC in his repair.


.... Phil