lee wrote:
On Thu, Nov 27, 2008 at 07:06:42PM +0200, Rob de Graaf wrote:The headphone connector is for headphones, it is not for connecting recording devices: If the voltage and/or current are too high/much, you can damage the soundcard.An input which measures voltages (here the microphone input) has infinite large impedance, hence no current will flow. You are correct by the amplitude of the voltage.How can there be voltage (or voltage measured) without current flowing? http://en.wikipedia.org/wiki/Volt: "The volt is defined as the potential difference across a conductor when a current of one ampere dissipates one watt of power." no current <--> no voltage
The wikipedia article is correct as to the definition of a volt in mathematical terms. However, voltage is the electrical equivalent of water pressure. You can have water pressure, even if there is no water flowing (i.e. a full water tower with no water flowing out).
You still have a voltage across a battery, even when no current is flowing. And you still have voltage at your outlet, even though no current is flowing.
Now, there is no such thing as an infinitely large impedance, but microphone inputs are higher (typically 200-1K ohms for dynamic mics, the most common used today). Headphone impedance is typically 4-8 ohms.
Without getting into the more technical stuff, for correct operation impedances need to match. Any mismatch lower performance. A small mismatch probably won't be noticed but a larger one will.
Additionally, headphone output is typically a few watts maximum, while microphones work in the micro watt range.
With all of this said, you can connect a recording device to the headphone output - but you will need an adapter to convert the impedance and power from the headphones to what the recorder can accept.
BTW - there is a third standard - some devices have a "line out" and others have a "line in". This is defined as 1 volt peak-to-peak across a 1K ohm impedance. It is made just for such operation.
So if your sound card does not have a line out, but your recorder has a line in, you might be able to find a device which will convert from the headphone out to the line input, more easily than you can to a mic input.
Sorry this is so long - but hope it helps.