Yeah, I agree with The Wuss.  I am rather new to the headphone amp universe.  So, don't choose to (or not to) buy baseed on my review alone.    I listening to the HiFiMAN EF2A through my Grados and a pair of Sony Studio Monitors I use for live music mixing.  The Sonys were instantly revealed as crap for critical listening.  The Grados came to life and quickly taught me what the term "muddy" was all about.  This amp reproduces the upper lows through the lower mids as though they are on top of each other.  These frequencies are fuzzy and sound...