Re: [LAU] ground loop hell

On Mon, 16 Feb 2015, Roger wrote:

> On 16/02/15 11:51, Len Ovens wrote:
>>
>> It seems even with all power coming from one outlet, I have one amplifier
>> with some hum. It is way less and by playing with levels I was able to make
>> it so low as to not be noticed. However my plan of isolating everything
>> should fix it completely.
> Look at the signal cabling or even nearby EMF sources. I recall ages ago

Over 100 ft of unbalanced input. The hum was not there with the power
ground lifted (now fixed). I will be Changing things so I have balanced
out of the mixer -> through snake -> one to one isolation transformer ->
unbalanced to amp.

My final setup will be: all stage powered instruments or unbalanced
sources will have a DI (transformer with ground lift), All returns to
stage will have isolation transformers. Mics go straight.

Anyway the hum was low enough that I had to tell people it was there, so I
am at "good enough". I do have two pots at max and one very low to get it
to work that way though. I will see what my isolation box does.

--
Len Ovens
www.ovenwerks.net
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