Hi! I am a pianist new to bass. Now, I am considering a practice amp, but they seem to be a little expensive for my budget. I found an audio interface called Behringer um2 and I tried it, it sounded pretty nice in my GarageBand, except a little flat, probably because I don't have a good headphones. So, should I spend the money on an amp like Fender rumble or stick with audio interface for now? Thanks!