Check over on www.audioasylum.com in the "tubes" section. This has been covered in some detail over there--you'll need to do a "search". Basically, it is not a direct sub--it will work in some cases, but not in others. The direct Russian sub for 6dj8/6922 is 6H23n. I can't tell you whether they will work in BAT equipment--but it may be on the audioasylum site. Good luck.