Types and number of inputs and outputs of an audio interface relate directly to using need, studio scale as well as expansion possibility of your studio.
- You should ask yourself what you want to record. Drum, singing, guitar, band,…?
- How many audio signal lines you want to record at the same time?
- Do you want to expand your studio?
After answering those questions, you’ve already known number and types inputs and outputs you need.
I list below some feature for you to consider:
1) Mic preamp: Number of microphone pre-amps ports on audio interface is the same as number of microphones you use concurrently at studio.
2) Analog input: Number of analog inputs on audio interface decides the possibility of recording number of electronic musical instruments like keyboard, drum machine, sound module,… or other external devices like compressor, reverb, eq,… you can use at the same time.
3) Analog output: Number of analog outputs on audio interface relate to number of external hardware such as EQ, Reverb, Compressor or devices relate to monitoring like speakers, headphone which you can use simultaneously.
4) Hi-Z input: If you want to record original signal from electric guitar, electric bass guitar, your audio interface needs to have high Z input (instrument input) port.
5) Digital input/output: If you want to use external converter, expanding scale intention, number of musical instrument, direct recording in the near future, audio interface with digital ports like adap , spdif, aes/ebu is very useful.
6) MIDI port: If you want to connect midi devices through audio interface, midi ports are compulsory. However, you can connect these devices through usb port on the computer by midi-usb cable, therefore, midi ports on audio interface is not very important now, I think it’s unnecessary. Because aside from midi-usb cable which is sold a lot on the market, you have one other choice, and it is the fact that many modern midi devices like midi controller, drum machine all have usb ports which connect directly computer.