Description: Dual op amp three times before the DC amplification empty board: compact double-sided FR4 fiberglass Board, the size of 26 26mm, suitable for small volume chassis assembly, to save space. High quality PCB, Japan KOA 1 / 4W colored ring precision metal film resistors (error through far less Than 1%), high-quality eight-foot hole seat assembly for voltage feedback op amp, such as the NE5532, OPA2134, OPA2604, AD826, OPA2111, etc., then 5 ~ 18 to work. Board leaving two mounting holes For easy installation. Classic line, although simple, spend a good op amp, such as the assembly with the gold seal OPA2111 Enable voice but wide range, High Definition force, rich in detail, tonal balance, the sound quality Depends on the merits of the op amp's performance, resistance the accuracy and quality of the content Element is also power can not be the end. Change the negative feedback resistor value can change the Magnification. You can also put the assembly according to prefer different types of transport. Package Included: 1PC*Dual op amp DC Pre-amp amplifier empty board