It's a very cool preamp.

- 6J1 still can keep good linear and working state when the plate voltage is low to 50V; So when using AC 12V power supply, you can boost the voltage to 28V to greatly extend service life and increase SNR;

- When using DC power supply, you only need to use low-cost crystal valve components (not included), no need high-voltage resistant components;

- PCB circuit layout is reasonable and beautiful, minimize noise, warm sound, perfact for listening singing;

- On-board volume control potentiometer, power switch, power input, audio input & output interfaces, convenient to use;

- Orange light LED on the bottom of the valve;

- Best for your desk headphone amplifier or home power amplifier, make the sound more warm.