Karaoke Forums

Ive recently bought a Dell inspiron 9100 and MTU Hoster and the external plextor drive. Im very pleased. Dell gave me a great warranty and tech support and the Hoster program is great.
The only problem Im having is with a terrible noise coming from the headphone out on my laptop but only when Im using the power supply. When Im using the battery its very quiet It only happens when Im plugged in to an outlet
Does anyone know why this would happen?

Mine does the same, (also a Dell)... its apparently something to do with the way the power source works, and a "non-switching" power source will fix the problem... but I haven't managed to get hold of one yet.....

Well, my powerbook is whisper quiet... My advice? Get a mac:)

(ohoh, pc people everywhere are kicking me...

But that is odd that that happens... When my husband gets home I will find out why that occurs.. you have me intrigued (he used to workas a supervisor/trainer for a company that made power supplies, etc...)

Ok, got the info.

Ok, if you are using the wall adapter, there is an ac to dc adapter... a cheaper one will not have any noise reduction, and will allow noise, which is interference, that will end up travelling through the computer, but will interefere with audio, because headphones run on ac.. so an intereferring noise will interere with the headphones.. you could use a capacitor inline with your headphones, if you knew what frequency the noise was.... etc.. or get a better wall adapter. Sometimes what you can do is buy ferrite bead from...an electronics supply store, it comes in a plastic hinged case, take the cable leading FROM the wall adapter, TO the computer, make sure it is the cable AFTER the transformer, wrap the cable around the ferrite bead, once or twice, and then close it.


Ok, I have NO idea if what I jsut said made sense.. i asked him this as he was going out the door..a dn then tried to write it all down before I forgot:) WHich, if anyone knows me.. happens VERY quickly:)

Yep. A ferrite bead might work for this problem. You can usually pick them up at any electronics supply store or your local neighborhood Radio Shack.

Another possibility is noise coming in from another source. Try using a good noise recuction power strip to see if it helps to solve this problem.


On a side note, how high is the output turned on the headphones? Many low end sound cards will emit noise if the output is turned up all the way (or almost all the way). This would apply to both the headphone output AND the master outputs.

Is the noise a high pitched static sort of noise or a low hum? Two different problems...

Of course if you were hardcore you could drop about $150 for the Extigy External Sound Card (by SoundBlaster) that connects to the USB port which would move all the DAC and amplifier sections off the laptop sound card and likely solve the problem as well.

I had the same problem with my laptop originally, all I did was move the power adapter to a different plug, one on a seperate breaker. As long as the laptop is the only piece of my setup plugged in on this breaker there is no noise. Not sure why but give it a shot.

I have fixed a half a dozen computers doing this with noises ranging from a shrill data stream sound to a low buzz-humm. the ONLY WAY to fix this xcheap and permanent and correctly id either a external usb audigy, or the "hum Eliminator" from a pro audio shop or the guitar center.

_________________
______________________________________
I'm Not Dead yet...... But every day Im getting Closer !

thanks for all the advice.I think I need to explain a little futher

Again when my pc is not plugged in , using the wall adaptor , it is quiet.
As soon as I plug it in , {not using the battery}, it is fine.
When I plug my headphones in it is fine plugged in or not.
Im using 1/8" to rca to rca convertor back to 1/8" then using a 1/4" adaptor, this is much, I know, but Ive played in bands for years and ran sound I have never encountered this before. I have tried running it to different circuits. This is more than a little hiss it almost sounds like a faze problem or something ,very anoying. Also the noise is worse when i move the mouse ,and when the beginning credits come up on a song the noise follows the scrolling text. When the music starts the problem is less evident , of course, but its still there and effects the overall sound.Once again if I use the battery its perfect.
I will take the advice given I dont mean to repeat myself but I just wanna be sure Ive explained my problem correctly.
Thanks again. This forum is a God send.

Like I said. I have the hum eliminator on both of mine they do this also.

this is from a ground loop in the sheilding

_________________
______________________________________
I'm Not Dead yet...... But every day Im getting Closer !

with all those conversions you leave yourself open to unsheilded interferrance. Hence the hum.

I've no experience with the hum eliminator, but I know that the soundblaster mp3 (usb connection with rca plugs) works just fine for us.

Before, we had the hum (and that was with no headphone... just hooking it up to the computer only at one gig.)

The Hum is been picked up by the ground & if you disconnect the outlet so it runs on batteries, it will be clean!

Dell computers has this problem and if you get an adapter that removes the ground like 3 to 2 it will be perfect!! It's what I do by the way!

Good Luck!

lift the ground like that, and you may have a singer complain of the mic shocking when it touches them. Be careful...... not recommended.

_________________
______________________________________
I'm Not Dead yet...... But every day Im getting Closer !

What do you mean, a shock from the Laptop??? I'm not saying to lift the ground from the amplifier or any other hardware but just the Laptop!!!

What do you say in the case of the Laptop running on the battery pack?

Pleeeeeease!!!

ok some suggetsions, some already recommended:

- cut down on the conversion of cable. If you need it to be 1/8 TRS to 1/4 TRS then have a cord made frm good quality sheilded cable. most music shops can do this.

- APC (i think) makes a in-line surge protector/adapter, this would hook between the connector that goes into the power supply for the laptop

- Ferrite Beads worth a try

- call Dell - i am pretty sure that the P/S causing the hum would violate the FCC part 15 rules