Short answer? Yes you can, but you need a few things:
- You’ll need an XLR to line cable (or adapter)
- You’ll need a dynamic microphone (one that doesn’t need phantom power)
- In the Spark app, flip all your components up to disable them (to make the Spark act like a regular audio interface)
In this test I recorded a song twice. Once with the Spark amp and once through my Scarlett Focusrite 18i20. I used an Ovation acoustic for both and a University Audio US658L microphone for recording with the Spark and Blue Songbird condenser microphone for recording through the Focusrite.
Yes you can record vocals with the Spark if you don’t have another audio interface. It sounds ok, but ‘thin’ compared to the Scarlett to my ears.