18 Jul
2010
18 Jul
'10
9:12 p.m.
Tony Duell wrote:
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.
-tony
Ben.