laptop -> audio interface -> speakers = noise.

yeah, i know this is a very common problem, but i dont have ever found a simple and clear enough solution to it, except of plugging my laptop out from the power supply.

any help?

1.You could cut off the plug of the laptop and put a new plug on it without connecting the ground. ATTENTION: Your laptop isn't secure then and you loose all warrenty.

so lets try 2 instead

2. Use balanced connections and cable (if the interface and the amp/speaker provide it).


peace

you should invest in power conditioner,

take apart teh outlet and ground it,

as suggested above use balanced cables

run your audio cables away from power cables

this sounds like a grounding issue...do balanced cables really fix that? my understanding of grounded cables tells me no...as they'd still be using the messed up ground.

now, balanced cables with one end ground-lifted....that would help.

This IS probably a ground loop. I use one of these in my dj setup:

http://www.amazon.com/Raptor-GL15-Ground-Loop-Isolator/dp/B0009O19LQ/ref=sr_1_1?ie=UTF8&qid=1317317329&sr=8-1

under $10, hum free

thank you. i noticed that when i disable the mpc monitoring from the 0404, i can listen to my music on the laptop through the 0404 to the speakers without the hum.

when i switch back the monitoring on, hum from the laptop comes back.

i say this in case it helps anywone to find where the problem in my setup is..


(edit..very bad english on this one lol)

On another post I wrote this

LZ Roberts wrote:I had exactly the same problem if the noise sounds like an old modem & when you move the mouse the noise changes a bit.

I had a Macmini & a FW Saffire LE. I kept sending the LE back to focusrite & everything, had the tech lads pulling their hair out because it was supposed to be uber fidelity & it clearly wasn't. Tried all the balanced cable stuff & cable routing but it clearly wasn't working.

Turned out that what the Macmini called 0volts & what the Saffire called 0volts on the Firewire were two totally different things.

The solution was to get a 6pin to 4pin converter and a 4pin to 6pin for the firewire cable. That took out the power wires from the firewire cable. Then powered the Saffire Le from an external supply.

The result :- utter & total perfection. Faders were full up on my Makie 1402 & still couldn't here a single squeek.

A friend had a really awful time with his Audio Interface & Laptop. He got another interface & that turned out exactly the same. It was the cheap & nasty switched mode power supply & supply circuit of his cheap nasty laptop that was doing it all along. He had to get another laptop. His original laptop was designed for internet and wordprocessing, which was fair enough as it made it cheaper. But once he got into audio it all went Foxtrot Uniform.

Don't think USB is quite as easy to solve - perhaps if you can find a way to cut out the supply wires of a usb cable. Wiki has the pin info
http://en.wikipedia.org/wiki/USB
Looks like you have to remove the wires to 1 or/& 5. or some permutation of on a cheap USB cable, then power the interface from an external supply. If you give this a go post back & tell us how you got on.

tapedeck wrote:this sounds like a grounding issue...do balanced cables really fix that? my understanding of grounded cables tells me no...as they'd still be using the messed up ground.

now, balanced cables with one end ground-lifted....that would help.

If you are only getting a light hum when other stuff is connected to the setup, like an MPC, mixer, FX or whatever, then that sounds like a ground loop problem. You will also get it if there is a ground loop problem between the Laptop & interface - and powered/active monitor speakers or amplifier.

Heres some info on ground loops

http://www.soundonsound.com/sos/nov02/a ... on1102.asp
http://www.soundonsound.com/sos/1994_ar ... loops.html
http://www.soundonsound.com/sos/nov04/a ... oblems.htm
http://www.soundonsound.com/sos/jun02/a ... iboxes.asp

http://www.channld.com/hum.html

quietizkept wrote:This IS probably a ground loop. I use one of these in my dj setup:

http://www.amazon.com/Raptor-GL15-Groun ... 329&sr=8-1

under $10, hum free

This sounds like an isolating transformer type DI