I wouldn't go so far as to generalise, I'm sure there might be some headphones(MySphere is one of them) or speakers that work like magic with 2A3s, unfortunately Sennheiser isn't one of them or Audeze, or Hifiman, or ZMF etc.. I branched out from the 2A3 family not because I'm a weirdo when it comes to tubes even if it might be true, there was a need for quality even the top 2A3s couldn't fulfil. The saving grace was the European 2A3 somewhat equivalents outside of heater such as PX4, AD1. There might be other such as E406n, LK4112. I don't want to take away from the quality of the Stellaris, I still haven't found out if it has a base sound outside of tubes, the wetness DNA amps are known for, Stellaris especially is due to tube selection, not the components themselves. Currently running U52, AD1 and C3g, the resolving power with HD690 can easily keep up with a Utopia without the small stage.