Spring Line Hum

[Haible Juergen]

	>Absolutely. My DMP-8 Yamaha midi patch bay is a fantastic piece of
	>equipment but it hums very badly. I thought it was the mounting,
but
	>nope, its the whole transformer. I may therefore have a go at using
a
	>toroidal in its place.


That's funny, my "outsourcing" of the transformer was also done on a 
Midi Matrix (Miditemp PMM88). 

"So if we build an all digital box with
noise immunity around 1V (thresholds of digital gates ...) we don't
have to care the f*ck about stray fields. And if it couples into sensitive
3rd party gear, let that be *their* problem. We can use the cheapest
transformer available, and we even get a big "+" in the next review
for not using a wall wart."

I like it, I like it ...

But the best thing of all is that if you ever sell your modified box,
you have to argue with the buyer that the toroidal transformer is
a feature, and not a reason to lower the price. Ha !

JH.