Laptop causes Hum or hiss?

[ukpartydj]

Hi I've recently bought a couple of new not so powerful / expensive laptops as my current laptops are overkill really for my DJing and one of the laptops (my favorite) creates a hum / hiss when the USB soundcard is plugged in!?!

The hiss is outputted through the mixer.

I've tried all my other laptops and they do not create the sound. I'm guessing it's not the cable as it doesn't do it on other laptops which would mean that the laptop itself isn't grounded properly maybe??

Any ideas what could help solve this?

[DJRecardo]

Try putting a ground loop isolator inline between the sound card and mixer, it usually solves the problem and they only cost a few quid

[ukpartydj]

Try putting a ground loop isolator inline between the sound card and mixer, it usually solves the problem and they only cost a few quid

Hmmm, sounds like it would solve the problem - bit of a pain though! Cheers

[Shaun]

Yep, definitely sounds like you need a ground loop isolator. The laptop hum is one of the most queried problems here on the forum. Do a quick search and you'll find lot's of advice and opinions regarding this. :beer1:

[DiscoPromotions]

Have you tried a different usb lead... some of them are not good..

[ukpartydj]

Yep, definitely sounds like you need a ground loop isolator. The laptop hum is one of the most queried problems here on the forum. Do a quick search and you'll find lot's of advice and opinions regarding this. :beer1:

Will do, not sure the search is working properly for me though just comes up with lots of unrelated recent topics!


Have you tried a different usb lead... some of them are not good..

I don't think it's the lead as my other laptop works fine but I'm going to grab my mixer out of the van and have a play around with my spare leads just incase.

[Kernow]

one of the laptops (my favorite) creates a hum / hiss when the USB soundcard is plugged in!?!
I've tried all my other laptops and they do not create the sound.

Any ideas what could help solve this?

Change favourites ? :lightbulb: :D

[ukpartydj]

Oddly enough I've plugged everything in at home and there is no noise!
Starting to think that maybe it's more an issue with one of my extension leads or even the main supply at the hotel I was working at.
I didn't check the ground on the plugs at the hotel because I checked them a few months back and regularly go there.

I've managed to eliminate -

Mixer
Soundcard
Cables
Power supply to laptop

I've tested a couple of my extensions and they are fine so it's either one of my extension cables or the venue that has the faulty ground I would assume.

[ukpartydj]

Change favourites ? :lightbulb: :D

I wish i could, I bought it especially for an illuminated keyboard though and i love it!

[Kernow]

I wish i could, I bought it especially for an illuminated keyboard though and i love it!

But your issue (and I'm pretty sure the clients too) revolves around sound, not the lightshow ? ;)

Hope you get it sorted :thumbs_up:

[DazzyD]

Oddly enough I've plugged everything in at home and there is no noise!
Starting to think that maybe it's more an issue with one of my extension leads or even the main supply at the hotel I was working at.
I didn't check the ground on the plugs at the hotel because I checked them a few months back and regularly go there.

I've managed to eliminate -

Mixer
Soundcard
Cables
Power supply to laptop

I've tested a couple of my extensions and they are fine so it's either one of my extension cables or the venue that has the faulty ground I would assume.

I think that the purchase of a ground loop isolator would be a hell of a lot cheaper than a complete rewire of the venue!! ;)

[katman]

Oddly enough I've plugged everything in at home and there is no noise!
Starting to think that maybe it's more an issue with one of my extension leads or even the main supply at the hotel I was working at.
I didn't check the ground on the plugs at the hotel because I checked them a few months back and regularly go there.

I've managed to eliminate -

Mixer
Soundcard
Cables
Power supply to laptop

I've tested a couple of my extensions and they are fine so it's either one of my extension cables or the venue that has the faulty ground I would assume.

As others have mentioned, a ground loop isolator is a cheap and guaranteed fix for your problems.

That will ensure that you wont have the problems in other venues as well.

[ukpartydj]

But your issue (and I'm pretty sure the clients too) revolves around sound, not the lightshow ? ;)
Hope you get it sorted :thumbs_up:

HA HA! ... ... ...


I think that the purchase of a ground loop isolator would be a hell of a lot cheaper than a complete rewire of the venue!! ;)

Not my problem :D lol


As others have mentioned, a ground loop isolator is a cheap and guaranteed fix for your problems.
That will ensure that you wont have the problems in other venues as well.

Yer I might as well buy one or two, I am just very curious to what the problem actually is... even if it was the venue one of my laptops didn't make a noise and the other did :daft: it seems like a cheap and easy fix but I won't be happy until I know where the hell the noise is actually coming from!!!!

[ukpartydj]

I HAVE THE ANSWER!!

The issue is not the venue's, not my extention leads but the charger itself.
I swapped a laptop charger with another charger, exactly the same voltage and hertz on the back (Always check the output figures on your mains adapters - I've destroyed a TV by plugging an incorrect lead in before).
And there is no hum hiss or anything, whichever laptop this particular charger is plugged into it will make it hum or hiss through any of the USB ports or headphone jacks!

Solved and no need for Ground Loop Isolators!

[Dynamic Entertainment]

I HAVE THE ANSWER!!

The issue is not the venue's, not my extention leads but the charger itself.
I swapped a laptop charger with another charger, exactly the same voltage and hertz on the back (Always check the output figures on your mains adapters - I've destroyed a TV by plugging an incorrect lead in before).
And there is no hum hiss or anything, whichever laptop this particular charger is plugged into it will make it hum or hiss through any of the USB ports or headphone jacks!

Solved and no need for Ground Loop Isolators!

I suspect that your old charger had the earth pin (connector like a 3 leafed clover), whilst you're new charger is double insulated...hence no earth what so ever?

[ukpartydj]

I suspect that your old charger had the earth pin (connector like a 3 leafed clover), whilst you're new charger is double insulated...hence no earth what so ever?

Whilst that would make sense both chargers are the clover type hence they both have earth - I personally cannot see any logo / detail on the back that indicates they are different in any way so I'm assuming that one charger is prehaps of a lesser quality or simiply doesn't have something the other one does :confused:

[Dynamic Entertainment]

Whilst that would make sense both chargers are the clover type hence they both have earth - I personally cannot see any logo / detail on the back that indicates they are different in any way so I'm assuming that one charger is prehaps of a lesser quality or simiply doesn't have something the other one does :confused:

Pass....the earth wire is connected to the pin in the plug on the second one isnt it?

Ive seen some do a custom ground lift with that technique :daft:

[Excalibur]

- I personally cannot see any logo / detail on the back that indicates they are different in any way

If I remember correctly, the symbol for double insulated is one square inside another square. You can check if the earth is connected in the mains lead very easily with a multimeter.

[ukpartydj]

Pass....the earth wire is connected to the pin in the plug on the second one isnt it?
Ive seen some do a custom ground lift with that technique :daft:


Both chargers have 3 pins which seem to connect at the clover male and female & at the wall plug so I'm assuming both are grounded.
They are both Dell chargers which came with the laptops when purchased although the one that causes the hum and hiss is a funny shape (thin and flat rather than a mini brick).

Just done a few more tests just to see if I can get to the bottom of this - the hum and hiss never happens at home regardless of the charger however the last 2 venues I've played I have tested it before setting up and it has caused the sound.

Very bizzare but the good charger is the one thing that constantly solves the problem, been reading other online suggestions and quite a few people have mentioned it's the charger also.

From what I understand the ground loop issue is when their is 2 items or more which are grounded, they are connected together and the noise is where the appliances cannot decide which ground to use.


If I remember correctly, the symbol for double insulated is one square inside another square. You can check if the earth is connected in the mains lead very easily with a multimeter.

I may try and dig out my multimeter to check but the double insulated logo isn't on the charger.

[SoundONE]

Even if the PSU did have an earth it wont on the DC side, the problem is caused by the power supply smoothing circuit basdically cheap or underated capacitors in the DC circuit, a psu with better regulation will cause less hum it's as simple as that. The sign as someone said for double insulated is a square inside another square, but regardles of insulated or double insulated the DC side will not be conendcted to earth.