EF86 / Z729 / 6267 / EF806S / CV4085 / M8195
The EF86 is a high transconductance pentode for AUDIO frequency applications. It was introduced by Mullard in 1953 and was mainly produced by Philips, Mullard, Telefunken, Valvo and GEC. Its ancestors are the EF37A and the EF40. Unlike other pentodes, it has been designed specifically for audio applications, as it has low noise and microphonics and very high gain and its mounting is recommended on a vibration resistant rubber base. In recent decades, in the development of tube hi-fi it has been used in many preamp designs.
EQUIVALENT: 6CF8 = 6Ж32П = 6267 = 6BK8 = Z729 = 6F22 = CV2901 = CV4085 = M8195 = EF806S