Introduction Many of us have come to know John Massaria, either from the custom modded version of the Kennerton Gjallahorn JM Edition or more recently, the closed back Hifiman dynamic driver offerings including the Drop HE-R7DX and Sony/Fostex inspired HE-R9. John and I are both based out of New York, so when he asked if I wanted to hear his latest mod, I immediately took him up on the offer. Having previously owned and thoroughly enjoyed the R7DX JM Mod, what I was expecting was another Hifiman… but what I received was something I haven’t seen...