Ok so i want to hook up a somewhat expensive external amp (and speakers) to my computer to listen to mp3's... But the "front out" on the NF7 board (nforce2) is able to power headphones, right? That would mean that the output isn't true "line-level" and the output impedance is really low... Basically the output is like attaching the amp to a headphone jack of a CD player, rather than hooking it up to the rear line out jack.... Is there a way to make the jack "un-powered" so to speak so that i can attach it safely to the external amp? Thanks a lot.
Unless you turn off the computer, no. Basically, based on the electrical principles, you're worried that you'll fry the amp by plugging it into the front-out jack? I don't have a technical explanation for you, but you don't need to worry. People have been using various amps with their PC's without isssue. If this were a serious problem, then people wouldn't be doing it. Some audiophiles have a whole system running from their PC and not had a problem. If you're still worried, you could use the Toslink optical out if that's something useable on the amp or even a receiver like some people have done.
you should be able to attach any kind of amplifier or speakers to any kind of audio output safely. if not then there is a problem. a computer shouldnt be able to do any damage to any kind of amplifier.
I have the yamaha ax-596 integrated amp... I asked a yamaha tech person about it and he said that you shouldn't hook it up to a jack that supports headphones on the computer... what the hell? he said i would likely blow the input stage... On my last creative labs card, when you plug in headphones, and turn the volume up even to half, it feels like you would blow the headphones... I never even went past that level... Clearly the signal isn't "line-level"... So I don't understand the physics behind how it can double up as a headphone jack AND line-level.
Any green output on any souncard will support headphones. I'm really not an audio expert so I will try to interprete why it is not dangerous to plug a receiver or an amp in this green output. In a computer, you have the hardware and the software. So the user can use the software to modify the hardware's behavior. Through your soundcard's software, you are able to select how many speakers you have hooked in. I would guess that when you select headphones or a two speaker setup, the output impedance is influenced by your choice. This cannot be done on a receiver or an amp because you cannot change how it handles what you hook up in it. I used to plug my receiver in my soundcard and it's still working perfectly (actually it was an amp with preamp...old and cheap stuff, Kenwood though) Take this with a grain of salt as I am no expert.
Unless Abit is deviating from the color-coding standard (PC99 I think), the green is the front out jack for the front speakers or headphones. While some sound cards might have a headphone jack, they're not as common. Off the top of my head, the only sound card that has a headphone jack is the Hercules Fortissimo II, but it's long since been discontinued.
Thanks for the help guys... But for a jack to support headphones, it is technically a headphone jack... Line-level outs do not have the power to drive headphones... Maybe i'm being over cautious
I think you're sweating it out far too much. Unless Abit or Yamaha isn't conforming to spec, you should be fine. While I don't have that Yamaha unit or the NF7, I have run a 1/4" jack to a reciever (with a 1/4" jack to L/R RCA plugs for sound). Nothing fried. The reciever is still working just fine. I realize it's not the same thing, but the electrical specs of the same component aren't (or at least shouldn't) vary from manufacturer to manufacturer---except fluctuations within limitations.
http://forums.pcper.com/showthread.php?t=333777 According to that link, the newer line-out/headphone jacks are unpowered.
