Audio interface is the gear piece that make the conversion from acoustic audio to digital signals and vice versa. We often talk about "AD/DA" converters which mean "Analog to Digital / Digital to Analog". Without this, you just can't record clean sound sources in a computer or output the sound of your computer into speakers. So obviously, all computers and smartphones are natively equiped with AD/DA, but their mostly for listening to music and microphone use, not conceived for professional music usage.
What to watch on audio interface :
- Number of physical input and output.
- Number of digital input and output
- Maximum resolution in bits (minimum 16bits)
- Maximum sample rate in kHz (minimum 44.1kHz)
- Connectivity to computer
- Additionnal connectivity such as MIDI
- Extensibility format such as ADAT, S/PDIF or MADI
- Alimentation source (external or USB powered)
- The [preamp](Preamp.md) quality using the things to whatch on these pieces
- Number of line and Hi-Z channels for using line instruments in direct such as guitar i.e.
- Embedded processors like [DSP (Digital Signal Processor)](DSP%20(Digital%20Signal%20Processor).md) or FPGA
References :
- [Antelope Orion Studio Synergy Core](https://www.thomann.de/fr/antelope_orion_studio_synergy_core.htm) - ~2700€. 12 premps, thunderbolt 3 or USB 2, ADAT, 6xDSP 2xFPGA, real-time effects processing up to 128 effects per session. Interesting to note that Antelope also provide modeling [microphones](Microphones.md) and that the interface can handle the vintage mic library emulations.