YAQIN MC-84L 6P14 x4 Class A Vacuum Tube Integrated Amplifier High-perfomance ultralinear push-pull circuit bring out rich acoustic SRPP preamp circuit widen frequency response and lower distortions Output transformer is made of Japan audio-specific oriented silicon steel (0.35mm) and free-oxygen high-intensity enameled copper wire,To widen frequency response and better acoustic quality ,transparent and powerful Adopt audio-grade Electrolysis and Philips MKP non-polar AC capacitor Make it low-noise,quite music background and durable. Headpohone jack available.