The cct. brd. for the ESP low noise two transistor mic preamp attaches to the lid of the this solid die-cast aluminum case. Batteries also are mounted on the cct. brd. This preamp is free from hiss and all noise and is the perfect partner for high quality low output mics. A more compact version could be constructed using electrolytic caps and AAA batteries (12V). But the quality would suffer a little with the inferior caps.
