In article , Dave Plowman (News)
scribeth thus
Bought a bit of audio gear from the US at a decent price even allowing for
carriage. Guessed it might be 110v - but it is actually marked 120v 60Hz.

Looking inside, it has an analogue power supply - I was rather expecting
an SMPS.

The transformer primary has two winding wired in parallel which seem to be
coil 1 black start brown end, coil 2 red start orange end.

Red and black are paralleled as are brown and orange. Red/Black goes to
neutral, brown/orange to the off/on switch.

So it looks like I may be lucky and simply altering them to series will do
it for 240v. Link brown and red and 240 goes between black to orange?
Does it matter if one winding has the connections reversed when they are
in series?


Yes, they'll cancel out!...


Have you got a VARIAC or similar to test it with before, close switch
and retire to a safe distance?..
--
Tony Sayer