🚀 go-pugleaf

Hello,
	I have been building some low-level audio circuitry, and have had
problems with hum from nearby AC transformers.  Currently, I have the power
supply located a great distance away from my circuitry in order to eliminate
the hum.  The sort of transformer I need is 120VAC to around 20 VAC
center-tapped, at a few V-A's. As I understand, Toroid transformers can have a
much smaller radiated EM field than usual transformers. 
	There are several manufacturers of toroidal power transformers,
but they all seem to want an arm and a leg ($50+) for even the smallest
transformers.  Does anyone know of a more inexpensive source for these?
Alternatively, is winding my own toroidal transformer out of the question?
I have wound several RF toroidal transformers, but I imagine that a totally
different core material would be used in a 60 Hz transformer, and saturation
of the core would be a big concern.  Do any toroidal core manufacturers
give information on using their cores in 60 Hz transformers?  I'm looking
for the sort of information Amidon gives on their cores - sort of a cookbook
procedure on how to make your own transformer.

						Thanks (in advance),
						Tim (Shoppa@erin.caltech.edu)