The Summit Audio 2BA-221 is a continuously variable impedance microphone preamp and line input with individual solid-state outputs and a valve out.

Featuring microphone level, line level, and Hi-Z instrument inputs, the 2BA-221 utilizes separate and individually controlled solid-state input controls to mix the microphone input with the Hi-Z or line input into the variable vacuum tube output. Mix them together through the 12AX7A/ECC83 vacuum tube output or separately through individual solid-state outputs.

The Summit Audio 2BA-221 also features a stackable input design; multiple 2BA-221's can be linked together to form a modular mixing device with individual outs, inserts per channel, and a final vacuum tube gain stage. Its swept high pass filter, multiple simultaneous tube and solid-state outputs, insert jack, and internal power supply makes the 2BA-221 a powerful tracking and mixing tool.