i currently have a 50 watt crate bass head out of a bx 50 combo. i really like the tone that i get from it but i need more power since im running it through 2 15s rated at 600 watts rms. i was thinking about buying a power amp and running it through that but my head doesnt have a line out. it has a headphones out and a speaker out. so would it be possible to hook it up through the power amp. and the cab?