77

Common name: RCA 77

Production Status: Discontinued / Vintage

Dating from the late 1930s the RCA 77 is a directional ribbon design using the classic technique of combining a pressure and pressure gradient response. Suffix A and B versions have one half of the split ribbon acoustically terminated in a labyrinth to give the omni pressure element. They have a permanent cardioid response. The C version allows the halves to be selected electrically to give cardioid, omni or figure-of-eight responses. The D and DX version use a full-length mechanical shutter to adjust the polar response and have a switchable LF roll-off. Impedance can be changed with internal transformer taps.