Without a doubt , best bang for the buck, get what ya paid for product I've purchased in a long time is the Rupert Neve Designs RNHP Precision. Headphone Amp. This amp sounds amazing with my Grado RS2e ! Made in USA , built like a tank, has XLR/TRS combo, RCA, and 1/8 mini inputs . Built and feels like an heirloom product.
I am hearing content , textures , and spatial cues I have never heard in CDs I've played a hundred times. It's spooky how it puts things in space like they are way beyond your head. . Best $500 spent in a long , long time.