Pentode
Designs using the 6J1 / 6J1-J tube have recently become very
popular in Asian made condenser microphones, especially
the CAD Trion 8000, as well as the new crop of low cost,
high quality Chinese preamps such as the Douk D2 and Little Bear P5-1.
They are also used in many Chinese manufactured Recording
Microphones. The Shanghai ShuaiYin factory; for example,
has SYT-2000 and SYT-3000 mics that use them.
These 6J1 / 6J1-J vacuum tubes were produced in China during
the 1970's. For a much higher quality tube, use an American 5654W military tube.
Preferred Substitutes ................6AK5, EF95,
5654W, Mullard 8100 & CV4010
Substitutes .........6F32, 5591
The 6F32 and 5591 tubes are not exact Direct Replacements.
However they are compatible with them.