I don't know how and why, but it certainly can be. I recently bought a brand new inventory leftover Adcom GFP1 preamp with a separate headphone amp section, for just about $160. It's over 20 years old, but it drives both my self-powered bi-amped monitors as well as my 600ohm Beyers absolutely flawlessly. Excerpts from an old review: "The preamplifier's noise ratings are -90 dB (high-level) and -87 dB (phono) with A-weighting; both exceed our measurement capability" "The GFP-1 can obviously be considered, for all practical purposes, distortionless" Here's the full review: http://www.hifi-classic.net/review/adcom-gfp-1-295.html There's one on ebay just now for under $60, in case you're interested. Bottom line: DO NOT believe all the marketing hype out there!