Re: Laptop recommendations

[<biz-looper@groovetronica.com>]

Because the audio signal from the USB port is analog, and shares the ground
over the USB connection with the laptop and its power supply, so once the
audio gets out of the digital domain, it gets messed up.

I've tried isolating the laptop ground from the mixer, by severing the
ground on the audio connection between the two, but no luck. Perhaps
severing the ground of a USB card attached to the laptop? Since the card
would be grounded through the audio cables, I don't see any danger of
damage, but I don't have the electrical engineering knowledge to know if
this would work.

Works fine with headphones though...

----- Original Message -----
From: "mark" <sine@zerocrossing.net>
To: <loopers-Delight@loopers-delight.com>
Sent: Wednesday, April 02, 2003 11:03 AM
Subject: Re: Laptop recommendations


> That doesn't seem to make any sense to me... USB is digital data.  Gets
> fed into a converter which then sends an analog signal to a
> preamp/mixer/poweramp stage.  I'm unaware as to how the laptop could
> affect the D/A converter.  The digital signal would have to have the
> noise embedded in it... no?  Does anyone know about this?  I cleared up
> a noisy internal sound-card on my mac by just putting a transformer on
> the output.  (it's cheap you can buy them at radio shack, they're made
> for car stereos but work fine for this problem)
>
> Mark
>
> On Wednesday, April 2, 2003, at 10:36 AM,
> <biz-looper@groovetronica.com> wrote:
>
> > a horrible and unavoidable hum occurs
> > when you plug them into any kind of mixer or power speakers. There is
> > no
> > solution - it even happens with USB audio.
>
>
>