I managed to pick one of these up brand new earlier this year for a steal (NZD $450 - about the same price as a pair of Sennheiser HD-498's for your reference). I use it mainly as a headphone amp, but also to drive some obnoxiously large floor-standing speakers. I always thought the headphone amp sounded pretty damn good, but I managed to borrow a Lehmann Rhinelander to compare for the past few weeks. The Marantz surprisingly sounded as good as the Rhinelander with my AKG K-812 and Sennheiser HD-800. This is despite the Rhinelander being a dedicated headphone amp (with rave reviews) costing twice as much. If anyone is in the market for an affordable integrated amp that can drive a pair of high-end headphones, I can't recommend it highly enough.