The Neumann TLM 170 is the precursor to the TLM 170 i and TLM 170 R, All three had a pattern select switch that also included a second cardioid pattern with a letter R inside it. Only the TLM 170R actually included circuitry to allow for remote pattern switching. What you have is the more desirable of the three versions. If it's in good working order and pretty clean looking and smelling then it should be worth $1500 or more. They are more collectible, feature a more neutral sound than the U87 and especially U87 ai. They are excellent in a classical setting or more natural setting. Best for strings, brass, woodwinds, classical voices and bright voices. Yes, the TLM170R has more features but less warm of a sound due to it's IC's and not as hand-made. The 170's all feature the same capsule as the U89 which is slightly smaller than the U87's. It also is edge terminated. I have 4 of the TLM 170i. They are very versatile and neutral. You've got a great mic there.
