An NOS (new old stock) Mullard 6AU6A vintage vacuum tube, microphone tested for signal and quiet noise floor, for replacement in the Sony C37A and C800g and Altec 21B and the Schoeps CM61 microphones.

This tube was made by Mullard in Great Britton for the Brazilian market.  The mallard M logo is visible on the underside of the tube inside the ring of pins.

Our tubes are microphone grade and have been tested for noise levels.

FYI:  Here a link to details specs on this tube!