Buzzing over pa when laptop power lead is plugged in

[discomobiledj]

Nigel's back then!

[Corabar Steve]

The voice of reason was in the first reply to this thread.

Has somebody deleted Shaun's post then? All I see is a post by you

[Rowleys]

back to the topic..

I have has this very same problem for ages now and can say its doing my head in.

I have 2 ground loopers as i use a 5.1 usb sound card and use 2 channels out so i use two loopers.

This still does not fix the problem.

I used to be able to connect a external monitor and it would stop but now that's stopped working .

Please help

[Excalibur]

The voice of reason was in the first reply to this thread.

Don't milk it pal, I'm not going to praise you twice in one thread.

back to the topic..

I have has this very same problem for ages now and can say its doing my head in.

I have 2 ground loopers as i use a 5.1 usb sound card and use 2 channels out so i use two loopers.

This still does not fix the problem.

I used to be able to connect a external monitor and it would stop but now that's stopped working .

Please help

Try a different power supply. Sometimes helps.

[CRAZY K]

Don't milk it pal, I'm not going to praise you twice in one thread.



Try a different power supply. Sometimes helps.

Wise advice, electricity is a strange thing--I worked at an Xmas Party in an ancient Village Hall recently which appeared to have some "intereference" on the mains circuit which caused intermttent noise over the radio mike---never had the problem before---never had it since

Far as I know there wasnt a beer cooler on the same circuit

More recently, in my kitchen I have an extension lead with a 4 gang block.

I use it for running my laptop, Hi fi amp/speaker, a reading light etc, for some UNKNOWN reason if I plug in a sound to light unit/ chaser and plug in my floodlights the floods dont work--if i plug it into other single plugs in the kitchen it works fine--very strange thing electricity

[Rowleys]

well a little update with new power pack the noise is well controlled but still there just a little bit in the bass

but I'm happy with that as it was really bad

[Alchemy]

This problem only happens with cheap, mass produced switched mode power supplies. They automatically switch between 100v and 240v so only one adapter is required wherever the laptop is sold in the world. The safest alternative solution to the ground loop isolator is to source a fixed 240v power supply with the correct DC power output (You could try this Rowley).

Removing the earth obviously does isolate the RF noise and if the adapter is in good condition it offers a very minimal risk (don’t attack it with a screwdriver). However, as has been pointed out in earlier posts it is amateur solution to an issue that can be easily and cheaply solved with a ground loop isolator.

[Rowleys]

like i have said ground loop does not work on this noise we are getting.

i have no idea but I'm looking to move from laptop to a PC system and not use a laptop

[Alchemy]

like i have said ground loop does not work on this noise we are getting.

i have no idea but I'm looking to move from laptop to a PC system and not use a laptop

What I suggested was to buy a fixed voltage power supply (240v) with the same power output as your switched mode power supply. This should completely cure the noise (and you won't need the GLI).

[sleah]

If after adding GLIs there is still hum, then look elsewhere. It may be a GLI is need elsewhere in the signal path, such as between the mixer and amp.
It may be worth moving the GLI around as well as adding additional ones.
Also check where there is an earth that it is good.
Chasing hum in a signal path can be a right !