Lauten Audio LT-321 Horizon Cardioid Tube Condenser Microphone Lauten Audio’s LT-321 “Horizon” is a large-diaphragm, fixed-cardioid tube microphone with unusually high sensitivity (32 mV/Pa) and high output. The mic body is milled brass; reviewers comment on the excellent fit and finish. Brian Loudenslager “It is built like a tank.” The mic’s high output level, which can be padded back by -10dB OR -20dB via a switch on the mic body, makes getting a good sound less reliant on having a high-end mic pre in the signal path. The large-diaphragm capsule measures 32mm in diameter, with a 26mm diaphragm made of imported German Mylar from Dupont. Lauten Audio LT-321 AssemblyThe amplifier circuit uses a military-grade NOS pentode, a 6J1, as does the input stage of Lauten’s dual-tube Oceanus. These tubes were considered “scientific” grade when manufactured by Peking Electron in the early 1980s, and compare to a Mullard M8100. The output circuit uses a custom-wound transformer (source unknown). The Horizon ships with its dual-voltage (115v/230v) tube-mic power supply, a Gotham power cable, a mic clip, an elastic shockmount, a storage pouch for the mic, and a flight case.