A cost effective way to replace any 12DW7, the Electro-Harmonix 12DW7 rivals increasingly rare NOS 12DW7. One side has a gain factor of 100 - the other side has a gain factor of 20. You can think of it as 1/2 a 12AU7 and 1/2 a 12AX7. Try this tube for some interesting gain reduction effects on certain amps. Please Note: Due to the fact that the 12DW7 has two triodes with completely different gain factors, this tube cannot be balanced.