Loud buzz when USB Audio Mixer connected

[glrothman]

I've been happily and successfully recording from a Alesis USB Mixer to my Dell Windows XP running 1.3.13. I just bought a Toshiba Portege laptop running Windows 7, and I get a loud buzz whenever the mixer is connected -- even if the mic pots are turned all the way down and the mics unplugged. (to be precise, Audacity is recording a loud buzz -- it's the main component of the audio. When I have the mic opened, that sound IS heard on top of the buzz). Audio is main reason I bought the laptop, so if it won't do this right, I have to return it.

Is there a fix?

Should I replace the laptop with a Mac?

Your help is greatly appreciated!!

Gordon

[kozikowski]

Should I replace the laptop with a Mac?

I'm not a good one to ask that being one of the Mac elves.

Setup to record so you can see or hear the buzz. Disconnect the laptop wall power and make it run on batteries. Disconnect the network if it's hard-wired.

Still buzz?

Koz

[glrothman]

I did try with the AC unplugged; no difference.

[waxcylinder]

Nor am I the right person to ask - I'm a Windows ellf
You do realize that questions of this nature are likely to bring out the zealots on both sides and even the hair-shirt Linux brigade may weigh in ...

But seriously though, before I would even conside new hardware I would be trying to borrow another PC or a laptop (or even a Mac) to see if the buzzing is still there. If not then the finger points at the mixer not the PC.

Are you sure the kit is all grounded properly and that you don't have a mains loop created inadvertently (for example my TT requires goo gronding at my ART phono pre-amp, otherwise a loud mains hum results ) and all my kit is powered off the same extender block powered out of a single wall socket.

WC

[glrothman]

The mixer still works with my desktop PC, and the buzz is there even when the laptop is on batteries

[waxcylinder]

Ok - so are all the leads plugged in properly with clean connectors and pushed (gently) securely home in their sockets?

And you're not using a USB hub, right?

Another thought: Have you tried a different USB input on your laptop?

WC

[glrothman]

I've used the usb ports for data, in and out, no problem. And the usb plug is in solidly, and tried in 2 different ports

[waxcylinder]

So for my money it's pointing the finger at the laptop - I hope you kept the receipt ...

My recording chain which is: Turntable=>ART phono-pre-amp/FM radio/TapeDeck=>SkyTronic passive switch=>Edirol UA-1EX=>computer
records to either my desktop or laptop (both Dells, both XP) without hum and a very minimal noise floor (requires a lot of Effect >Amplify applied to even see/hear it at all).

WC

[glrothman]

It's barely out of the box; I think it's going back