Rarely available on the market, the HPA-01M earns its legendary status for its unique proprietary approach using current based amplification. This is sublime with my power hungry Audezes and HD800S driven in current mode. Reviews all around, universally positive, and arguably the best portable amp right now. Unit in consideration comes in a complete box set, and is mint and perfect, aesthetically and sonically. Price offered is a steal. Flat fee of USD25 shipped anywhere! Paypal fees upon the buyer. Thanks for looking!