Here’s an exploded view of the XR-Spectra pickup from the bottom. The Preamp board connects to the coils via a small 2×6 pin 1mm gold-plated connector. The 2×6 pin has redundant connections to the coil for greater reliability. The preamp board is held in place by 4 screws. For passive operation, the preamp can be replaced by the passive board (not shown).
The preamp board has a 2×5 pin 2.54mm gold-plated connector for connecting to the outside world. The connector includes pins for:
- Main I/O: Standard EMG style I/O
- VCC: 5-18v power
- MIX: Preamp output
- External Coil: Connect to an external passive coil (e.g. a second XR-Spectra passive pickup) for double-width (quad-coil) configuration.
- MIX SHUNT: A shunt placed here will disable the mixing resistor for ultra-low output impedance, enough to drive the Tone Block.
- EXT SHUNT: A shunt placed here will disable the external passive, if one is connected to the external coil pins. This can connect to a switch for single-double width switching.
Here’s the unexploded bottom view of the XR-Spectra pickup.