[Trevor]

"Scott Dorsey" wrote in message
...
In article , Trevor
wrote:
Most of the modern mixers with inbuilt supplies are switch mode, so the
transformer is small, light, and operates at high frequency, so little
problem putting them in the box now.

That makes the noise issues even worse!
Now instead of something spewing 60 Hz magnetic fields into your quiet
electronics you have something spewing high frequency magnetic fields
AND electrical fields all over.

Take a look inside one of the newer Allen and Heath cheapies and look at
some of the extreme measures they've had to go through to keep switcher
noise
under control. It's beautiful work.

And you don't see a contadiction there, or is the Allen and Heath still
"spewing high frequency magnetic fields
AND electrical fields all over."? Or is it simply a design problem engineers
already know how to overcome?
And do you really need to mix audio signals in the frequency range the
switch mode PS operates? It is well above the audio region for a purpose
after all, it's easily filtered out. More easily than 50/60Hz transformers!

Trevor.