I jumped on these.  I'm hoping they can replace my Etymotic ER4SR.  The ER4SR do not have enough weight in the lower registers for my tastes.  

Quote:   Different deigns of amp and use of different components all contribute to a sonic signature.  ie the methods they achieve those stats can be different.  There are several designs of tubes for tube amps.  Each one has a different sound.  Transformers have their own sound depending...