25 May
2007
25 May
'07
1:54 p.m.
On Friday 25 May 2007 02:48, Loki Davison wrote:
On 5/25/07, Ken Restivo <ken(a)restivo.org>
wrote:
A couple of thoughts Loki. Would an AC filter (such as on old computer
equipment) resolve a problem like this ? Or perhaps one of those ferrite
cores, like are on the monitor cable, and I see I have one on my webcam cable
as well.
I did see the ferrite core option suggested some time back when someone had
interference showing up on sound output.
Nigel.
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On Sat, May 19, 2007 at 11:40:16AM +0200, Pieter Palmers wrote:
Have you tried groundlifting the power supply? Worked for me... until
i found a better solution, throwing out the laptop and getting a
desktop. ;)
Loki Pieter Palmers wrote:
Thanks for your help! The USB M-Audio Audiophile exhibited the same noise
problem. Then I unplugged the laptop's power supply and ran off of
batteries, as you suggested, and there was blissful silence!
The problem was the power supply.
Any advice on brands/distributors of good *quiet* laptop power supplies?
The cheap-ass "Delta Electronics" supply (19v, 3.6A) that came with the
laptop obviously sucks, and the only other 19v laptop power supplies I
have around here are only 1.8A.
- -ken Ken Restivo wrote:
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>
>I plugged my spiffy new linux laptop into an amp tonight and used it
>as an instrument with a band, using an M-Audio Axiom49 as a MIDI
>controller.
>
>Not everything works yet on this new machine, but what I needed most
>for tomorrow night's show (specimen, with a couple specialized
>samples), worked fine.
>
>Except for the noise. The FA-66 was producing the most awful, buzzy,
>glitchy digital background noise.
>
>I ran the following chain, and got horrible aliasing noise: Laptop ->
> ExpressCard Firewire -> FA-66 -> SWR bass/keyboard amp
>
>The FA-66 is powered by its wall-wart, since the ExpressCard doesn't
>power it (even though it is a 6-pin connector).
>
>My question is this. What's up with that awful noise?
When googling around I found at least one other person having the same
issue with the FA-66.
I've noticed similar noise at some places with my QuataFire line
out's.
Some things to try:
- unplug the power supply of the laptop (for test)
- put a DI box inbetween the amp and the edirol (enable ground lift)
- use another power supply for the edirol (preferably a transformer
based one).
http://docs.info.apple.com/article.html?artnum=86655