The Sunrise Pickup needs to be matched to a high-quality pre-amp or active DI box. Users on the guitar forums report excellent results with a range of units including the BSS A-133, the Ultrasound DI-Plus, and the Baggs Venue DI or Para DI. However, for closest matching there are the Sunrise SB-1 and SB-2 preamps.
The Sunrise Preamp Buffer Box is a line matching device designed specifically to access the coupling feature built into Sunrise Pickups. They provide the pickup signal with 12dB of gain, high resolution, and impedance matching capabilities. The active 18 volt Bi-Polar powered circuit eliminates pickup loading and line loss due to long cable runs, and also delivers up to 4 years of battery life with 2) 9 volt Eveready Alkaline batteries.
Unlike the S-B1, whcih is a mono preamp, this S-B2 is a stereo version, and is designed to preamp the Sunrise Pickup along with a piezo pickup with each signal being sent through its own preamp circuit, and then to the outputs (Sunrise and Aux) with the piezo signal sent to Aux.
The S-B2 produces the widest frequency response possible from a battery powered preamp, and allows the Sunrise Pickup to operate at its full design capabilities.