Based on the RCA BA-2 preamplifier, this build has up to 50 dB of gain. Built with an original set of transformers and two 1620 tubes, which are a low noise 6J7. It is a simple, but beautiful sounding microphone preamplifier.
A point-to-point build on terminal strips. The output tube is transformer coupled with the tube plate coming through the primary of the transformer. This allows the amplifier to have higher headroom on the output and eliminate the blocking cap before the transformer.