difference be tween a codec and an amplifier?

[Gibson486]

I don't know if this belongs here, but i want a sure answer.

How does an audio codec differ from an audio amplifier?

is the difference that codecs can be used from everything from decoding/encoding the stream to outputing the signal where as amplifiers are only used for outputting the signal?

Do codecs use amplifiers?

 

[Mark R]

A CODEC is an analogue-to-digital converter and a digital-to-analogue converter combined in a single chip.

This means that one single chip can handle playback and recording of sound - it makes the design of sound-cards simpler, because you only have to use one chip, make one set of digital connections, and you don't have to design special logic or programs to cope with the ADC and DAC running simultaneously.

Some CODECs have built in amplifiers (some have microphone pre-amplifiers only, some have headphone amplifiers as well). Some don't.

An audio amplifier boosts an analogue signal - it can be used for boosting very weak signals (e.g. microphone signals) so that they can be accurately processed by an ADC, or they can be used for boosting a signal so that it is strong enough to power speakers or headphones (if you just connected headphones to a DAC, the DAC wouldn't have the strength to produce much sound).

Very crudely, the budget ones are designed for budget products, so tend to have integrated amplifiers - because it saves having to use a seperate amplifer chip and circuit. The high end CODECs tend not to have amplifiers, as it is expected that sound-systems using expensive high-end CODECs will also want to use high-end amplifiers.

 

[Matthias99]

Just to confuse the situation further, a "codec" can also be a software package capable of decoding and encoding audio files of a particular compressed format (such as MP3, FLAC, etc.).

But Mark covered hardware encoder/decoder chips pretty well.

 

[Gibson486]

Originally posted by: Mark R
A CODEC is an analogue-to-digital converter and a digital-to-analogue converter combined in a single chip.

This means that one single chip can handle playback and recording of sound - it makes the design of sound-cards simpler, because you only have to use one chip, make one set of digital connections, and you don't have to design special logic or programs to cope with the ADC and DAC running simultaneously.

Some CODECs have built in amplifiers (some have microphone pre-amplifiers only, some have headphone amplifiers as well). Some don't.

An audio amplifier boosts an analogue signal - it can be used for boosting very weak signals (e.g. microphone signals) so that they can be accurately processed by an ADC, or they can be used for boosting a signal so that it is strong enough to power speakers or headphones (if you just connected headphones to a DAC, the DAC wouldn't have the strength to produce much sound).

Very crudely, the budget ones are designed for budget products, so tend to have integrated amplifiers - because it saves having to use a seperate amplifer chip and circuit. The high end CODECs tend not to have amplifiers, as it is expected that sound-systems using expensive high-end CODECs will also want to use high-end amplifiers.

OK, so the codec modulates and converts the signal, then it goes through a DAC....then it goes through an amplifier.......

ADC--->codec--->DAC--->Amplifier

Also, I am guessing that codecs today are usually all in one solutions where the ADC and DAC is included and maybe even the amp?

 

[Mark R]

Originally posted by: Gibson486

OK, so the codec modulates and converts the signal, then it goes through a DAC....then it goes through an amplifier.......

ADC--->codec--->DAC--->Amplifier

Also, I am guessing that codecs today are usually all in one solutions where the ADC and DAC is included and maybe even the amp?

Not quite. The codec is the DAC.

A typical sound card might be arranged like this:

PC -> PCI bus -> DAC -> Amplifier -> Sound out
PC <- PCI bus <- ADC -< Pre-amplifier <- Sound in

The codec is a integrated solution that has both the DAC and ADC on it (and may have amplifiers). So an sound card designed around a codec may look like this:

PC <-> PCI bus <-> Codec <-> Sound in + Sound out