P6SMB6.8AT/R P6SMB6.8AT3 P6SMB6.8AT3G P6SMB6.8AT3G 超小型管 P6SMB6.8AT3G(6v8a) P6SMB6.8ATR P6SMB6.8ATR13 P6SMB6.8C P6SMB-6.8C P6SMB6.8CA