[PD] noisy soundcard

[padawan12]

If you can get hold of a transformer PSU for your laptop
that is a very reliable solution. It's not really a question
of ground "loops", so much as switched mode power blocks tend
to float at up to 80 volts above ground, especially the cheap
ones. They throw off horrible little spikes at 100Hz where the
triac cuts each cycle and those propagate everywhere.
Another fix might be to power the Edirol from its own transformer
instead of using USB to power it, then make a USB cable that 
is data only, no power.


On Sun, 11 Mar 2007 22:53:12 -0400
Martin Eckart <imartron at gmail.com> wrote:

> Hi all,
> 
> I've had an annoying hum coming from my edirol FA-101 when I hook it up 
> to PA systems and have finally figured out that it occurs only when my 
> laptop is plugged in and not running on batteries.  The FA-101 is also 
> plugged in (boo 4-pin 1394 connections...) and then the amps I run into 
> are also 3-pin plugs and leads me to believe that this is probably a 
> ground loop issue.  Can anyone suggest possible solutions?  Is there a 
> power bar that isolates grounds?
> 
> -martin
> 
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