I was temporarily using this as a preamp until I received the NUPRIME IDA 16 integrated amp. Now it's time to sell, it's in great condition and comes with original box, remote and manual. The HAP-100 is a preamp and headphone amplifier for the audio enthusiast for whom quality headphone listening is a priority. The HAP-100's innovative design offers features never before available at its modest price point. Most significantly, the HAP-100 shares technologies first employed in our flagship P-20 preamp, along with other audiophile-grade developments.