[Phil Allison[_4_]]

gareth magennis wrote:

------------------------


Sorry, my post probably read a bit arrogant, but I think you will find all
your problems are down to the wall wart switching adaptor.

See if you can find/borrow a suitable linear alternative to prove yes or
no.


** That is not a practical suggestion.

Yamaha supplied a SMPS adaptor because the output was high current and well
regulated.

Finding a suitable *linear* alternative may prove impossible for the OP.


If the piano has built in speakers,


** It has a HP jack and no other connectors.

yes it will have quite a hefty wall wart
supplied with it.


** It has a high current, SMPS supplied with it.


You could still test for hum/noise using a low current alternative,


** I have a 1.2V to 12V, 5A bench supply with SFA hum which could be used - I even have some 12V, SLA batteries that definitely have no hum.

But YOU are trying to tell a non technical poster what to do while failing to put yourself in her position in relation to knowing how to identify or where to start looking for an almost non-existent type of PSU.



..... Phil