The SV83 is similar to EL84 Tube Types, but is not a direct replacement for these types. Matching is not usually required, so the price is for a single tube. Our current stock is branded by Svetlana as well as the original Russian part number 6n15n (6p15pi).
The popular Monoprice 25W hybrid amp (model# 13194) used two of these. They refer to them as 6P15 tube. The SV83 tube is the Russian version. If you have a Monoprice 50W amplifier (model# 16153) you will require the 6P1P power tubes.