"Arny Krueger" wrote in message
...
"Jim Lesurf" wrote in message

In article
om,
David Lodge wrote:


Is there not another angle to look at (says he throwing
fuel on the cynical fire...) and that is when the mains
power supply is noisey.

This is why amplifier designers tend to pay attention to
ensuring the amp has a decent PSU, and has some level of
inherent noise rejection. They also live in the real
world. Indeed, the mains supply in many factories or labs
can be even worse than domestic mains in terms of the
interference added to the basic mains waveforms.

While I can appreciate a mains cable ain't going to make
any difference with a clean power supply, to what extent
do these noise reducing mains cables with their ferrite
rings and platted cables reduce an interference that may
be inherent in the supply?

The biggest EMI filter in most power supplies is the power transformer. If
its optimized for efficiency at 60 Hz, its likely to be a good rejector of
higher frequencies.

**You'd be wrong. Particularly in the case of most toroidal types. An
efficient, close coupled power transformer can exhibit an excellent HF
response.


--
Trevor Wilson
www.rageaudio.com.au