Pros: Dimensional, detailed, smooth, rich sound; very comfortable to use for long periods
Cons: Few options for amps due to normal bias
Bought my Sigmas in the ''80s, after trying all the available Stax products and preferred the sound of the Sigmas by a wide margin. Until recently have used them sparingly since I never really cared for the energizer/solid state amp combos I had available and thus spent far more time listening to a variety of speakers. Found a mint Stax SRM-T1W amp/preamp, and now I truly enjoy these 'phones. Plus the passive preamp section works quite well with the amps I now own when it's time to use speakers.