Adorama offers the Sennheiser HD 650 Over-Ear Headphones in Titanium/Silver bundled with the Apogee Groove USB DAC and Headphone Amplifier for $499.95 with free shipping. That's tied with our mention from two weeks ago (which had rebate hassles) and the lowest total price we've seen for this bundle. (It's also $233 under the best price we could find for these items separately elsewhere.) These open-back circumaural headphones feature a 10Hz to 39.5kHz frequency response, 300-ohm impedance, detachable cable, and aluminum voice coils. The DAC features 24-bit/192kHz resolution.