SoundCard interference noise

[Luís]

I've just got a V6V-8088P notebook (1.86Ghz Sonoma, 1 Gb DDR2, 80 Gb 5400rpm, radeon x600 128 Mb, AC97 Audio).

When I plug headphones or external speakers to the line output, I hear a loud and horrible noise from the computer, like the processor and/or hard drive working. There's a constant noise, but when I start an aplication, you can hear (very loud) the processor or hard drive working. This doesn't happen with the onboard speakers. I've tried the asio4all drivers, but the problem continues.

I've used a Toshiba notebook, with AC97 audio, and there wasn't this noise.

It looks like an interference, or hardware problem.

This is very dissaponting. I hope you can you help me please.

[Sle]

This noise is always present to a greater or lesser degree in non-professional audio hardware, especially if it's built into the motherboard. It's also more noticeable in headphones.

If reading this brings cries of "No, you don't understand" you need to claim a new laptop under warranty - maybe the shielding on the headphone connection isn't up to scratch.

Or buy a nice little external audio interface.

[Martin Walker]

Agreed - some motherboard soundchips are better than others (the one on my Compal CL50 isn't at all bad) but you tend to hear tiny noise far more when under headphones than when listening on tiny built-in laptop speakers.

However, I bought an Echo indigo PCMCIA audio interface to provide me with even better 24-bit audio quality.

Martin

[Luís]

Even when I move the mouse or touch the touchpad, you can hear interference while the mouse icon moves...

yaaccchhhh...

[Sle]

Yes, that's what it's like.. Though remember - if you *render* your music to a file, your bog standard soundcard isn't even involved.

[James Covell]

Hi Luis and all,

Just reading the thread with interest... I have been experiencing similar problems. I've just bought a Toshiba M40X-189 (solely for music production). I'm running Cubase SX 1, I have a 7200rpm USB2 hard drive for audio data and I'm using a M-Audio FireWire Solo audio interface.

After a few tweeks here and there, the whole system runs perfectly - even with 30 tracks of audio, waves compresser+reveb pluggins and Halion running a 1Gb sampled piano! I am very pleased with the performance. There's just one major problem to be overcome now... bloody INTERFERENCE!!...

I get a truly awful two-tone hum constantly + additional noise when I move the mouse etc. Probably exactly the same noise Luis is getting. Even when using the M-Audio interface the noise to signal ratio is still unacceptable. What is really weird - even if the channel fader is down on the mixer, the noise still gets through!! -the mind boggles!

The only thing that stops the interference is unplugging the power supply and running the laptop off the battery (worth trying Luis).. which obviously isn't an option for long sessions. I've tried different manufacturers of power supply with no success.

Can anyone offer any advice?

Cheers.

James
PS. I was using an Echo indigo I/O card at first - I thought the FireWire Solo would solve the problem...

[Luís]

Hello James,

Runnig with batery > there's no noise.

The problem only is I just have 2 hour batery life, so that's not a solution for me

So, there's a ground loop in the notebook.

Could a DI or a ground loop isolator like this (http://www.xitel.com/product_gli.htm) solve the problem?

Anyone have already tried one of this solutions?

Cheers.

[Loudbox]

I had exactly the same problem with my Acer 1670 laptop. No problems with my RME Fireface firewire soundcard which is powered externally. However I had loads of noise and interference with my Echo Indigo PCMIA card when powered by mains. I spoke to a guy I know who runs Orchid Electronics . This is apparently a common problem and he has built a transformer isolator box. It has jack inputs and male XLR outputs. I ordered one for £44 inc vat & postage and it worked beatifully. Very well made and very robut for gigs.

[James Covell]

Hi Loudbox,

Cheers for the reply.

Does the isolator box effect the audio in any way?

James.

[Loudbox]

Does the isolator box effect the audio in any way?

No, the sound isn't affected in anyway at all. In fact it provides a very clean, isolated, balanced signal to your mixer, pa, soundcard etc.

[Luís]

Hello James,

I've tried this:
I plug the notebook to a wall plug in other room of my house (where isn't pluged any piece of my studio) and there was no hum

Then I remembered:
I've got an old Zeck DBA10 DI box. I plugeg the notebook back in my studio and there was hum again... Them I put 1 chanel through the DI (I only have 1 DI box) and guess what? THERE WAS NO HUM

Is this the best solution?

I'm going to buy anohter DI box (or a stereo one) for the other chanel.

Cheers.

[Martin Walker]

Yes, in many cases this is the best solution, and many people here have bought stereo DI boxes like Behringer's Ultra DI20 and been well pleased with them.

Martin

[jammer]

Yes, in many cases this is the best solution, and many people here have bought stereo DI boxes like Behringer's Ultra DI20 and been well pleased with them.

Martin

hi martin,

is there no way that the power into the laptop can be cleaned up?

so using this with my motu traveler i'd need a transformer isolator / DI box for every cable going to/from the traveler?

tia,

[James Covell]

Hi all,

Yeah, I've been experimenting too... if I plug the outputs directly into my powered monitors I get a perfectly clean sound. If I touch the earth pin of my Yamaha motif synth into the socket the interference comes through it's output into the desk (even when it's turned off!!- madness!)

As my audio interface has balanced outputs, I'm going to try some balanced jack-XLR leads tomorrow. I'll report my findings.

James.

[jammer]

i've just spoken to a couple of people about various solutions to this problem and it seems that using an adaptec fireconnect card and powering the traveler using that could be the best (neatest) solution.

according the the adaptec knowledge base online the fireconnect can power 3 devices

http://tinyurl.com/c9wkh

apparenly the pci system will filter the the noise from the laptops internals somewhat.

people have suggested DI boxes and so forth but this strikes me as a very messy solution, not to mention doubling the number of cables you'll need ... not good for a mobile recording solution, at least to my mind anyway.

[Martin Walker]

It's not cleaning up the PSU, but breaking the ground loop that gets rid of these background noises.

Martin

[Martin Walker]

James - if your powered monitors have balanced inputs then a balanced cable will do the trick for you.

Martin

[James Covell]

Hi everyone,

Well... I tried the balanced cables - unfortunately they didn't solve the problem. In fact they were worse for picking up general noise. So as a last resort I disconnected the earth from the laptop power supply. Perfect - no interference or noise what so ever. As for safety issues (see ground loops thread)... I'm not convinced that it's such a major problem. I know someone with a Samsung laptop (only a year old) and it's power supply isn't earthed at all. Take radio/cassette players, they have a standard two pin 'figure of eight' connection - that's mains power straight into the unit.

Luis and everyone else with this problem - just get rid of the earth on your power supply. Then you can get on with the important stuff like making music!

James
-Big thanks to everyone for their input.

[jammer]

Luis and everyone else with this problem - just get rid of the earth on your power supply. Then you can get on with the important stuff like making music!

James
-Big thanks to everyone for their input.

just remember ... your risking killing yourself or others.

[Martin Walker]

The big difference between those laptops with a figure of eight mains cable and the ones that are earthed tends to be metalwork on the case i.e. plastic cases generally have 2-wire mains cables, largely metal ones have 3-wire mains cables. if you remove the earth this will be floating, and in a fault condition could become live and be extremely dangerous.

On your own head (or heart) be it

Martin

[James Covell]

Hi Martin,

My laptop case is entirely plastic, and the power supply is a generic unit manufactured by a third party company. On the other hand my portable hard drive has a solid metal case. The power supply for this uses a 2 pin figure of 8 plug! - this MUST be breaching safety regulations.

James.

[James Covell]

just remember ... your risking killing yourself or others.

I was wrong to advise anyone else to do what I've done and I take that back. Do what you know is safe.

[Martin Walker]

Hi Martin,

My laptop case is entirely plastic, and the power supply is a generic unit manufactured by a third party company. On the other hand my portable hard drive has a solid metal case. The power supply for this uses a 2 pin figure of 8 plug! - this MUST be breaching safety regulations.

James.

Not if it's double insulated - many hi-fi amps, CD players, and so on have both metal cases and 2-wire mains leads with no issues.

Martin