I have a 4 piece rock band, I'm wondering what mixer would better suit my needs for recording. Now what I do is run my tape line out (power mixer) to the input on my soundcard and it all is recorded to 1 track on adobe audition for band practice. To record a good sounding song, I do all individual tracks at seperate times to a click track. I relize I need to update to the onyx sound card as well. I'm not sure what the difference is from the 1620 compaired to the 1640? Will there be a difference in the sound quality? If I can spend less money(1620) and yield the same results I would much rather do that, as would anyone.