The API Select T12 is a classic 2-channel, all-tube, Class-A microphone preamplifier designed with API's proprietary AP2516 transformer in the input stage and a custom API transformer on the output stage. Built with 12AT7WC and 12BH7 dual-triode vacuum tubes, the T12 represents a new and exciting variation in API's preamplifier technology and provides the user with unique tonal options.