Active Servo Voltage Regulator Power Supply For Preamplify

Active Servo Precision Adjustable Regulator Circuit with Ripple Comparable to a Batter 

LM317/337 high precision voltage regulation 

Output 3 voltages: ±12V, ±15V, ±17.5V 

PCB size: 75mm*75mm 

Input voltage (refers to the rectified voltage rather than AC voltage) is at least 3V higher than the output voltage. Do not be too high, the power consumption of the 317/337 will increase,if the voltage difference is too large.