Features 1.The product is a class A power supply HiFi preamp tone control board, very practical 2.Sound is warm and charming, pure and sweet, and the resolution is super high 3.Class A parallel HiFi tube preamp can provide excellent performance 4.4 knobs, can realize treble adjustment, midrange adjustment, bass adjustment and master volume control 5.Digital sound remover module possess stable structure, durable for a long service life Specification Item Type: Tone Board PCB Size: Approx. 140 x 66mm / 5.5 x 2.6in Product Weight: 133 g / 4.7 oz(approx.) Power Supply Voltage: AC12V-0-AC12V (filter capacitor is 16V withstand voltage) Potentiometer from Left to Right: Treble adjustment-midrange adjustment-bass adjustment-master volume control Package List 1 x Tone Board