RoHS date of introduction for Australia ?
Anyway 1/4 inch i/p socket too weak even for domestic use , breaking up in a
few years ( within RoHS regime), no obvious datecodes except main electros
seem to be 2000, otherwise maybe 2004 or 2005 IC dates. No-name flimsey junk
, the type with 2 insulated change over contacts. On trying to work out the
functions, apart from the tip contact/grounding setup there is a line to one
of the isolated switches that grounds at plug inserted and o/c when removed
, it goes DC connected to the base of a pnp transitor - function ?