Re: [LAU] Awful noise out of FA-66 -- SOLVED

On 5/25/07, Ken Restivo <ken@email-addr-hidden> wrote:
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> On Sat, May 19, 2007 at 11:40:16AM +0200, Pieter Palmers wrote:
> > Pieter Palmers wrote:
> > >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
> >
>
> 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

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
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Received on Fri May 25 04:15:18 2007