Digital Noise from laptop

[noisypickle]

Hello all.

I am hoping to get a solution, or at least a few ideas to address a digital noise problem I am having. Whenever my laptop is plugged in and charging I get a horrably loud amount of digital noise out of the system. This is the case regardless of sound card, computer, or venue. But as soon as I unplug and run off of battery, the noise disappears. I tried running off of a UPS, with similar results, UPS plugged in --->noise, UPS unplugged ----->no noise. I tried lifting the ground from my charger with quite a bit of success, but there is still easily decernable digital noise. Oh, also this has happened with SCS9 and 10.

I have run shows off of the battery up until now, and will continue to do so until I find a solution, but I gotta say that when the meter drops below 40% my anxiety level skyrockets.

I am running an HP laptop(HP Pavilion HDX9494nr) that has 7.1 surround onboard outputs, I have also used an external USB sound blaster card(5.1 surround outputs). One of my friends who also runs his shows on SCS used an IBM thinkpad with similar results, using the headphone output jack and a pcmcia sound card.

As far as the diffent venues go, one is in a building that is 50 or so years old with a questionable electrical system, but the second is in a new build (3 years old so I'm told), with electrical work that looks professional and would have had to pass inspection and is about 40 km from the first.

Suggestions, comments, questions please.

PS: Thanks Mike for the wonderful software, and your devotion to the people using it.

[Boswell]

It has nothing to do with the venue or the software.
The noise is from the switchmode powerpack (charger) and the only way to 100% get rid of it is to ditch the charger/powerpack and buy a different type ie a conventional one of transformer, rectifier, voltage regulator and smoothing. Putting audio isolation transformers in the output lines will remove the earthloop hum but will not stop the hash being received from the switchmode powersupply.
This is an old chestnut, and the above is the only 100% certain action
Hope this helps

[darrenmckane]

Hello,
Mr boswell is entirly correct, however inserting a $20 line transformer from Jaycar between your laptop and your PA is well worth trying and has fixed these problems for me (even if you listen really hard) many times before.