2013

Import 45
The device which is used to digitalize the audio signals is already built into most
sound cards and aptly called an analog-digital converter, often abbreviated with A-to-
D, ATD or A/D. In order to record sounds, the A/D converter takes samples of the
sound to be digitalized at fixed intervals by measuring the voltage level of the signal.
The frequency of the sampling is called the sample rate and naturally lies within the
kHz frequency range; several thousand times per second. The higher the sample rate,
the more samples are recorded by the A/D converter, thus making the sound
conversion closer to the original.
The precision with which the A/D converter measures the voltage level of the analog
signal is determined by the sample resolution. The same principle applies here: The
finer the resolution, the better and more natural the digital conversion.
Audio recordings in CD quality are recorded with a sample rate of 44.1 kHz and a
resolution of 16 bits.
Connecting the source for recording
First of all, the source of the audio material must be connected to the sound card
input. Again, there are several possibilities which primarily depend on the type of
equipment you have.
If you are recording from a microphone, then please connect the microphone to the
microphone jack on your sound card (usually red).
If you want to record material from a stereo system, then you can use the line-out or
AUX out jacks on the back of your amplifier or tape deck. This involves connecting
them to the sound card input (usually red).
If your amplifier has no separate output (other than for the speakers), then you can
use the connection intended for headphones for your recordings. In most cases, you
will need a cable with two mini-stereo jacks. This type of connection has the
advantage of being able to set the headphone input signal level with a separate
volume. As headphone connections generally are not the best, it is advised that you
use the line outputs if possible.
When recording cassettes from a tape deck, you can connect the tape deck's line out
directly to the sound card input.
When recording from vinyl records, you should not connect the record player's output
directly with the sound card because the phono signal needs to be pre-amplified. A
more suitable method would be to use the headphone connection or an external pre-
amp.