The polarity button is useful for getting something in phase, but sometimes, it's
insufficient. You need to get in between phase, hence the name IBP, which is what the IBP is designed for. It is also an incredible sounding line-level active direct box, has a buffered output for driving long guitar lines, and a phase-affected guitar output that can be used for re-amping.
 
The Little Labs IBP is a high-end, carefully constructed, analog phase-adjustment tool for combining two mic sources in situations where one microphone is out of phase, even if just a little. It is designed for discerning audio engineers who know exactly what they want to hear when it comes to combining multiple mics on a single source or when combining a DI'd signal with its miked counterpart. Use it when multi-miking any instrument, either for eliminating phase issues or adding color through phase shifting.

This device is rack-mountable—precisely speaking, it takes up 0.25 RU; you can fit four of them onto a rackmount tray. The device can accommodate mic, line, and Hi-Z signal, with the appropriate I/O for all three. You'll also find amplifier and re-amplifier outputs, making it a high-quality, buffered, and active direct box.
 
Circuit Topology
The IBP's unique phase circuitry is analog and passive, with gain make-up amplifiers with two in-series circuits selectable for smaller 90-degree phase adjustments or larger 180-degree adjustments to keep the pure audio path as short as necessary. Our research and development found that the passive approach sounds better. The active DI has an input impedance of 10M ohm. Themain balanced out is transformer isolated.
 
Ideal Applications
Combining two of the same things with fullness, punch, and clarity. Miced bass
cabinet and direct bass. Top and bottom snare mics. Direct and room mics. These are all places where the IBP will shine.