Laptop interference when through PA.....

Beans_On

Is there anyway to avoid that buzzing sound you get when laptop is running off the mains ( as in plugged in not battery powered)

i cant get any more than half hour battery life and need laptop for playing live.
(i see replacement battery s from dell around 170:rolleyes: )

I have an Inspiron 1300.

highlydebased

Mine suffers from that too.

Number of solutions. Rewire charger and do not wire ground

Or get a DI box

Or get a ground lift device. Maplin sell them now, you plug it between your laptop and mixer)

Soundman

The noise you are hearing is more to do with the Sound Card than the power anyway. Try getting a hold of an external sound card and try that instead.

ogy

Don't think its the soundcard, i have external soundcard and have the same problem. Its actually a problem dell laptop power supplies are notorious for having.

a combination of two things totally cleared it up for me were:
- using balanced cables (but this only works if you have balanced out on soundcard and balanced ins on desk)
- lifting the earth. very bold i realise but after thralling through www.prosoundweb.com forums i accepted that its the only real solution and that the risk of anything bad happening is fairly minimal. the pros over there seem to be of the consensus that this is the ONLY time this is ok. handiest way of doing this instead of messing with the adaptor for your laptop or buying something from maplins is to just lift the earth on an extension lead and always plug the laptop in through that (just don't plug anything else through it if its a multi one)

artvandulet

Mods, maybe this topic should be stickied with a list of solutions, its been asked so many times!:D

Anyway, as I've posted before, I use a PC Balance Box which does the job

TelePaul

The right angle rule is no good I guess?

highlydebased

TelePaul wrote:

The right angle rule is no good I guess?

Im not in the know...what is that?

artvandulet

I'm assuming he means running cables at right angles, ie. power ran perpendicular to signal instead of in parallel. This wont help you in this instance unfortunetly. You will notice that the hum goes away if you run off battery power though. But I'm assuming your battery life aint long enough for what you need.

Beans_On

Cheers for the replies folks.
I realise this is a common problem (with DELL laptops anyway) and im just wondering what my best option is.
Ive done a bit of googling and reading up on it over the last day or two and getting different reports back on the safety of removing the grounding.

I think i may just buy a battery off Ebay!Might be the cheapest option....

Advice appreciated.

DJ_Spider

You need a ground loop isolator. PCDJ have one here http://www.pcdj.co.uk/shop/item.php?id=77 But sure you could find one on eBay or try any of the good DJ stores, or Thomann. Don't bother with a battery, you wont get any decent results or time to use the laptop. Check out this thread on the PCDJ forum http://www.pcdj.co.uk/forums/showthread.php?t=485 Hope this helps.

thebookofbob

Problem you are experiencing is know as a ground loop. A simple solution is to buy whats know as an "audio isolation transformer". It effectively decouples the one device from the other. Maplin should sell.. If you're handy with a soldering iron.. PM me. I have a few lying around & they're actually already soldered to verro board so all you have to do is split an audio cable in half & solder to each side of the transformer. I'd recommend putting in a box of some kind, preferably metal to shield it..

Or.. buy a commercial one for like 10x the price :-)

Rob