meow2222 wrote...
elziko wrote:
1) Is the only reason you'd use a toroidal transformer to be able to use
a
dimmer?

Toroids should not be on dimmers. The advantage of toroidal is
reliability. Other than that they have nothing but downsides.



Not strictly true, in a lot of situations the reduced stray magnetic field
is a big advantage (I make music in my loft, last thing I want is hum picked
up on the signal cables), they're a lot quieter acoustically (ditto for
noise picked up by microphones), not suffering from the magnetostrictive
vibration like traditional E-I core transformers, and usually a little more
efficient and smaller.
The electronic "transformers" are actually switch-mode supplies, and
generate a hell of a lot more electronic noise than the trad iron-cored
ones, although they are dimmable while transformers generally kill dimmers
due to induced voltages at switchover unless the dimmer's particularly well
designed.

--
Dave H.
(The engineer formerly known as Homeless)

"Rules are for the obedience of fools, and the guidance of wise men" -
Douglas Bader