KORG Headphone Amplifier Kit Headphone amplifier with and vacuum tube amplifier for sound NuTekt HA-S - Nutube, DAC, high-quality

A high-quality portable headphone amplifier equipped with Nutube. The NFB (negative feedback) switch allows you to switch between a clean, clear sound and a warm tube sound. Two types of operational amplifiers are included, and can be easily replaced using IC sockets. Circuit diagrams are also included. Output impedance: 10 Ω, recommended load 15 Ω or more Power supply: Two AA alkaline batteries (sold separately) Battery life: Approximately 9 hours (when using alkaline batteries)