Sennheiser RS 140 using RS120 transmitter

[stvnpat]

I currently have Sennheiser RS120 headphones and want to upgrade to the RS 140 model. I have found several websites that advertise RS 140 headphones as "ADD ON". Can I use my RS 120 transmitter for an "ADD ON" RS 140 headphone or do I need the RS 140 transmitter as well.

[Crespin]

I think you have to take RS 140 transmitter for Sennheiser RS 140, but not sure about the same, in that case i would suggest you to concern some technical person around you who has very good knowledge about transmitter because it might happen that if you use wrong transmitter then it would damage your product.