It's not enough to have the best acoustic guitar pickup, you also need the best preamp to plug into. The term "best" gets thrown around a lot on the internet. For me, it means audiophile-grade components, overwhelming amounts of positive reviews and lightweight. It should boost the signal transparently, without coloring it. It should also be heavily shielded, built like a tank and stop feedback. There should also be some options for sculpting your sound, but not too many as to completely overwhelm. Some units out there literally require a degree in audio engineering.
After plowing though all the available pro options under 12 ounces, I found the Ai1 from GMF. It has a quality DI with preamp for use by professional musicians with added features for home or private practice, and also some helpful features. The Ai1 will easily fit in your gig bag and in most instrument cases. Designed for high fidelity, low noise and simple plug and play performance, the Ai1 is in a class of its own. It also happens to be ultralight and portable, running on a 9V battery or DC power supply. Perfect for acoustic guitar, violin, mandolin or just about any acoustic instrument with a pickup installed, even electric guitar and bass.
Another thing that sets the Ai1 apart, is the ability to run your mp3 player or phone through it. This is great for playing along with backing tracks. The addition of a headphone jack means you can practice and monitor the signal too. My goal with all gear is simplicity. I want as few knobs as possible but also the purest signal and tone. The bottom line is that a DI/Preamp brings consistency to your signal and GMF has emerged as the king of acoustic guitar preamps, giving us a DI that laps the competition. You gotta love audiophile quality gear that is also ultralight and suited for minimalist travel.
Combined with JJB 330 Prestige pickup, the Ai1 outshines the competition. This tiny unit boosts the signal transparently but also has key features for stage/studio use. The shape switch scoops out midrange mud while boosting the bass/treble. This feature alone is brilliant. From there you can fine tune with the bass and treble knobs. Expect a huge improvement in signal quality from this DI. Any further tweaking to tone should happen on your amp, PA, mixer or recording device.Google+