Build Your Own Phono Preamplifier Circuit (18V)

Circuit diagram

Components:

R1 47K 1/4W Resistor
R2 100R 1/4W Resistor
R3 6.8K 1/4W Resistor
R4 68K 1/4W Resistor
R5, R6 2.7K 1/4W Resistor
R7 2.2K 1/4W Resistor
R8 39K 1/4W Resistor
C1-C3 100uF 25V Electrolytic Capacitors
C4, C5 47nF 63V Polyester Capacitors 5% tolerance
D1, D2 BZX79C18 18V 500mW Zener Diodes
IC1 LM833 Low noise Dual Operational Amplifier
Q1 BC337 45V 800mA NPN Transistor
Q2 BC327 45V 800mA PNP Transistor
J1 RCA audio input socket

Comments:

Over time, following the rise of digital music formats, traditional vinyl records have become increasingly rare. Nevertheless, a phono preamplifier remains a valuable tool for enjoying older vinyl collections. This straightforward and efficient circuit, specifically designed for affordable moving-magnet cartridges, can be utilized in conjunction with both audio power amplifiers detailed on previous pages. It offers low noise, a favorable RIAA frequency response curve, low distortion, and good high-frequency transient behavior due to passive equalization within the 1 to 20KHz range. The transistors and associated components furnish a ± 18V power supply to the operational amplifier, enhancing headroom and the maximum output voltage.

Notes:

R2, R3, R4, R7, R8, C4 & C5 should be manufactured with a low tolerance specification.
The schematic illustrates the left channel and the power supply.
For stereo operation, R1, R2, R3, R4, R7, R8; J1; C1, C4 & C5 must be duplicated.
Numbers in parentheses denote the IC1 right channel pin connections.

Technical data:

Sensitivity @ 1KHz: 2.5mV RMS input for 200mV RMS output
Maximum input voltage @ 1KHz: 120mV RMS
Maximum input voltage @ 10KHz: 141mV RMS
Maximum input voltage @ 20KHz: 127mV RMS
Frequency response @ 1V RMS output: 100Hz to 20KHz ± 0.5dB; -0.75dB @ 30Hz
Total harmonic distortion @ 1KHz and 6V RMS output: 0.006%
Total harmonic distortion @10KHz and 1V RMS output: 0.02%

circuit from http://www.diy-electronic-projects.com/p17-Phono-Preamplifier