New 23+ Shadow Acoustic Guitar Pickup. Shadow electronics acoustic guitar pickups and preamps. Our nanoflex and nanomag pickups can be installed with a variety of mounting systems. By focusing exclusively on acoustic guitars, they've no matter which of these shadow guitar pickups turns out to be most in line with your instrument's fitment options and your own tastes, it's safe to say. For many guitarists, different types of acoustic pickups are a lot like the various positions of electric pickups: