19 Jul
2010
19 Jul
'10
5 a.m.
On 18 Jul 2010 at 22:12, Ben wrote:
Any chance you could simply change the orientation of one or the
other?
--Chuck
Certainly for
testing. RRun the heaters off a battery. If the hum
goes away, at least you know where it's coming from.
I found my hum ... Poor
magnetic shielding between the power supply
and the pre-amp output transformers. Not much I can do unless I can
order custom shielded chokes and power transformers as well as
shielded 10K to 600 ohm output transformers. I don't have the $$$ for
that, but it does prove you can get rid of hum if you don't use cheap
off the shelf parts, but parts made for low hum and noise.