Sunnaudio is a relative newcomer to the market, offering boutique preamps designed for acoustic instruments. The California company makes four products with similar electronics and sound quality, but with different form factors for different applications. The Stage DI ($299) is a standalone unit with volume, bass, and treble controls; XLR and 1/4-inch balanced outputs; and an effects loop. The TD-1 Tone Driver ($179) mounts inside the guitar to support a passive pickup system. The BL-1 Blender ($169) is an onboard preamp for dual-source pickup systems, while the LD-1 Line Driver ($119) is an endpin preamp, with an optional volume control. All of these preamps are battery operated, although the Stage DI can also be phantom powered.
For testing the Stage DI, I used pickups from K&K, Dazzo, Barbera, and McIntyre. The preamp was clean and very quiet, while providing enough gain (12dB) for low-output pickups, as well as a 5 Megohm input impedance to accommodate piezo pickups. The Stage DI’s frequency response is tuned to complement acoustic guitars. Its bass and treble controls offer gentle boosts and cuts, allowing you to tailor the sound to taste while avoiding extreme EQ. This results in a good tone regardless of setting, while still offering a range of sounds.
The frequencies of the tone controls are well chosen and very effective, and the preamp has an intangible vibe that is musical and pleasant to play through. Sunnaudio preamps should especially appeal to any guitarist who wants to put together a high-quality pickup system based around a passive transducer, although the Stage DI would also be appropriate for a player with an active pickup system.
This article originally appeared in the December 2018 issue of Acoustic Guitar magazine.