The Martin Thinline Active Jack is a miniature onboard preamp built into an oversize acoustic guitar endpin.

The Active Jack will give active performance to your existing Thinline 332 pickup or any piezo or magnetic pickup without additional modification. State-of-the-art circuitry is housed in the jack's shielding cap.

The Thinline Active jack will give you more than 12,000 hours of life from one 9V battery.