[Eeyore]

wrote:

Quick question...
I've got a mini mixing desk (Tapco Mix 60) that's useful for some live
stuff (running mic and guitar effects through loop pedal) but I've
managed to lose the power supply. Can't seem to find one anywhere (no
response from Tapco) and it seems to be a waste to buy a new desk.
Wondered about fashioning my own adaptor (weird input connector but
can open it up and take it in direct.
The only problem is it's rated at 2x 18VAC inputs and a third pin
which I assume is ground. Why two? Can I just get a single adaptor and
split it or are the two supposed to be out of phase or something?

Yes they are.

If they are the same and just done for current reasons (which seems odd
as it's hardly a lot of current) should they share ground?

The reason there are 3 connections is because the mixer operates on a so-called
'split' supply with both positive and negative supply rails.

You WILL need 2x18V (actually 36V with a centre tap).

Graham