Horrible sound from PC

[tgoyette]

Currently I am using my laptop as my primary source, with an Emotiva RSP 1 pre and a recently purchased Behringer Ep 1500 for power. Before I used the ep1500, there was always a slight hiss and buzz that was not audible during music playback. I assumed it to be some kind of interference from the power supply on my pc. After placing the behringer in the chain, the same nasty sound is amplified even louder, making it impossible to listen to music as it comes through louder than the music.
The hiss goes completely away when I unplug my computer, meaning I can only listen to music for about 45 min. until my battery dies. I was thinking of possibly replacing the power supply on the laptop as a temporary solution while I look into alternatives (like a media server or something comparable). Anyone with a similar problem that stopped this horrible noise? Any and all advice would be appreciated.

 

[Hi Ho]

Assuming you're using the headphone jack on your laptop, do you have the volume on your laptop set to maximum? If the output volume is set too low then you have to crank up the amp more, thereby amplifying the noise. If that isn't the problem then you have something else going on.

Laptop sound cards generally are not the greatest. Lesser designs in such a cramped space can allow interference from other nearby components to enter the audio stream. The layout of the motherboard is a big factor. My guess would be that your sound chip is (poorly) placed near the circuitry that accepts the input from your power adapter.

Your best bet is probably an external USB sound card.

http://www.newegg.com/Product/ProductList.aspx?Submit=ENE&N=2010360057+1102608535&name=USB

I generally recommend Creative, Turtle Beach, or M-Audio. Some of the other brands may do fine but I can't say for sure. They would have to be rather poorly designed if they didn't, at the very least, dramatically lower your noise floor (the hissing you hear).

 

[sparky77]

Have you tried to rule out a ground loop? Try to plug the laptops powersupply into the same outlet as the rest of the equipment to rule that out first.

 

[TLS Guy]

Has your laptop got a two or three pin power plug and what cable are you using out of your laptop?

 

[bandphan]

http://www.digigram.com/products/getinfo.php?prod_key=11500

used this to record a couple ratdog shows, the sound is awesome

 

[mouettus]

I lost my battle against hissing with my computer. The sound comes from other components in the case. Laptops are worse cuz the sound card is such in a confined space. Ground loops can be an issue too.

 

[mike c]

if the suggestions above don't work ... you might want to consider an external USB sound card.

 

[Halon451]

Currently I am using my laptop as my primary source, with an Emotiva RSP 1 pre and a recently purchased Behringer Ep 1500 for power. Before I used the ep1500, there was always a slight hiss and buzz that was not audible during music playback. I assumed it to be some kind of interference from the power supply on my pc. After placing the behringer in the chain, the same nasty sound is amplified even louder, making it impossible to listen to music as it comes through louder than the music.
The hiss goes completely away when I unplug my computer, meaning I can only listen to music for about 45 min. until my battery dies. I was thinking of possibly replacing the power supply on the laptop as a temporary solution while I look into alternatives (like a media server or something comparable). Anyone with a similar problem that stopped this horrible noise? Any and all advice would be appreciated.

I would agree with Hi Ho on this one - eliminate any basic potential causes first, check your output volume from the laptop to make sure it isn't set too low. You can plug everything into the same power source as well to make sure there is no ground loop issue. I've never experienced any noise/hiss with hooking up external speakers to any laptop I've ever owned, but I've also never hooked one up to an external amp - just your average powered speakers.

 

[tgoyette]

Thanks guys. I'm pretty sure it's not a ground loop as I have all my components as well as my computer (which is three pronged) plugged into the same power conditioner.
I am using the headphone out (stereo mini jack) on my laptop with the volume set to max on both the windows control as well as the particular program like Rhapsody. To connect to the pre I have to use a 1/8" stereo to RCA or "Y" adapter. Seeing as this is an unshielded cable, would looking for a shielded one help with the possible interference, or is it just an internal problem with sound card placement that needs to be taken out of the computer case?
Interestingly, the sound started when I began using the Emoitva as a pre as opposed to my old stereo Yamaha receiver which was silent (but didn't sound nearly as good as the current setup).

 

[TLS Guy]

Thanks guys. I'm pretty sure it's not a ground loop as I have all my components as well as my computer (which is three pronged) plugged into the same power conditioner.
I am using the headphone out (stereo mini jack) on my laptop with the volume set to max on both the windows control as well as the particular program like Rhapsody. To connect to the pre I have to use a 1/8" stereo to RCA or "Y" adapter. Seeing as this is an unshielded cable, would looking for a shielded one help with the possible interference, or is it just an internal problem with sound card placement that needs to be taken out of the computer case?
Interestingly, the sound started when I began using the Emoitva as a pre as opposed to my old stereo Yamaha receiver which was silent (but didn't sound nearly as good as the current setup).

A good quality shielded cable is obligatory. Do that first then get back to us.

 

[tgoyette]

Edit: My cable is actually shielded, I just checked it. It's a dayton audio.

 

[TLS Guy]

Edit: My cable is actually shielded, I just checked it. It's a dayton audio.

OK. Now put a ground break on the laptop plug, and tell us the result.

 

[tgoyette]

Thanks! It is now dead silent. So I assume that there was a ground loop. Forgive me if this is a stupid question, but does removing the ground from the laptop produce any risk of shock?

 

[Haoleb]

While you probably arent in any danger with the ground pin removed, It really is not the best permanent solution.

You may want to go to radioshack and get a set of the ground loop isolating RCA cables and use those inline. I had a ground loop with my computer and have been using these with great results. I believe they were about $20

 

[mike c]

Thanks! It is now dead silent. So I assume that there was a ground loop. Forgive me if this is a stupid question, but does removing the ground from the laptop produce any risk of shock?

i never use the grounds on ANY of my electronics because this house simply doesn't have grounds on the outlets. I have yet to be fried.

 

[TLS Guy]

Thanks! It is now dead silent. So I assume that there was a ground loop. Forgive me if this is a stupid question, but does removing the ground from the laptop produce any risk of shock?

Yes, it was a ground loop. Does your laptop have an in line adapter power supply? If it does I doubt there is a shock risk. You could get a two pin isolated adapter for it. When the laptop is connected to your sound system, it is grounded through that.

The "politically correct" thing to do is to get a ground isolator for your laptop, but that is spendy.

http://www.jensen-transformers.com/

 

[tgoyette]

What is an in line adapter power supply?

 

[TLS Guy]

What is an in line adapter power supply?

It is where there is a plug to the wall, then a box that supplies DC power to the laptop, and then a cable with a DC plug on the end which plugs into the adapter. This is the usual arrangement for laptops and the way my IBM is. Usually there is no ground on those adapters. I don't think I have come across a grounded laptop. All may children and spouses bring laptops to the lake and none of them are grounded and with mine that makes eight.

I think your risk of shock is minimal, and agree with Mike. I would not use cheap ground isolators. If you really want to do it the technically correct way, this is what is required.

http://www.jensen-transformers.com/ci2rr.html

 

[tgoyette]

OK so my laptop is exactly as you describe, meaning it is not grounded. So to use the transformer, would I plug the the two RCA outs from my computer into it, then use a separate RCA cable to run from the transformer to my pre?
Will I be able to plug my laptop into the power conditioner normally, as in three prong, while using the jensen?

 

[TLS Guy]

OK so my laptop is exactly as you describe, meaning it is not grounded. So to use the transformer, would I plug the the two RCA outs from my computer into it, then use a separate RCA cable to run from the transformer to my pre?

No it is grounded as for some reason the power supply has a three pin plug. I would just leave the ground break on, then it will be like any other laptop I have seen. There is only low voltage DC going to your laptop. There is NO risk of shock. Just use the ground break, be happy and don't worry about it any more.