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
Although you should use this solution at your own risk, I've solved this problem by using a 3-to-2 prong adaptor ... The more expensive solution is some kind of power conditioner, I believe...
~David
On 3/11/07, Martin Eckart imartron@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
PD-list@iem.at mailing list UNSUBSCRIBE and account-management -> http://lists.puredata.info/listinfo/pd-list
On Sun, 2007-03-11 at 22:53 -0400, Martin Eckart 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?
hello martin
lifting the ground of the power-plug would solve the problem, though it isn't recommended and might be dangerous. better would be to galvanically isolate your FA-101 from the amplifiers. this could be done by transmitting the soundsignal over a transformator. there are DI-boxes around with a ground-lift button, which do exactly that. but you could also buy an appropriate trafo and solder the necessary plugs to it yourself.
roman
Telefonate ohne weitere Kosten vom PC zum PC: http://messenger.yahoo.de
hi,
maybe reading this will help you finding the solution: http://www.davidemorelli.it/doku.php?id=other:ground_loops
patrick
Same discussion happens at Linux Audio User Mailinglist in the moment. My advice is to use balanced/ symmetrical cables if the Edirol and your mixer have balanced in- and outputs.
Cheers,
Malte
Malte Steiner media art + development -www.block4.com-
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@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
PD-list@iem.at mailing list UNSUBSCRIBE and account-management -> http://lists.puredata.info/listinfo/pd-list
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