I am thinking of purchasing 25 keys keyboard, but I am wondering if I need to also buy an audio interface to connect to a computer.
I will use no other instruments and no mics.
I am thinking of purchasing 25 keys keyboard, but I am wondering if I need to also buy an audio interface to connect to a computer.
I will use no other instruments and no mics.
You do not. Actually you probably won’t need anything but the keyboard controller itself. As long as you purchase a keyboard controller that has a USB connection that is compatible with your computer you will not need anything else. Older keyboard controllers had only MIDI jacks which required a MIDI interface to connect to the computer but pretty much all newer controllers have a USB connection.
If you get a controller keyboard then you will have to rely on your computer for generating sounds. I think you’re aware that this setup will not give you any audio capabilities other than the recording and playback of MIDI through the computer.
Pure MIDI keyboard controller does not have built-in sound, as opposed to a keyboard that has built-in sound plus MIDI capability. The MIDI messages are transmitted either via a traditional MIDI port, or for newer MIDI controller there is a USB interface which is in essence a virtual MIDI port inside the USB driver of a compatible OS supported by the device.
I have used a 25 MIDI keyboard controller Nektar SE25 which I can connect either to a Mac, PC, iPhone or even an Android smartphone (with the right adapter, such as a USB A female to USB Type C male that doesn't corrupt the MIDI message).
But then you need a software to produce the sound, translating the MIDI message + the General MIDI instrument collection to regular sound wave through your device's built-in audio interface, where you can then plug in your headphones or your speakers. There are a lot of free software out there, as well as iPhone/Android apps that can do the job.