19 Jul
2010
19 Jul
'10
2:47 p.m.
On 07/19/2010 12:12 AM, Ben wrote:
Tony Duell wrote:
Those that still remember the technology knew enough to loose mount
transformers
so they could be rotated for minimum hum pickup. Or they remote mounted
the power
transformer/power supply so the hum issue is less pronounced.
Allison
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.