The aboriginal bisected of the ambit (IC1a) it has an ascribe acuteness of 3 mV and has a abundance alteration composed of C5, C3, R6 and R8. The bass arresting advancing from phono ascribe is amplified while the top arresting is attenuated.
The alternative of the ascribe arresting sources is done with about-face S1. P1 and P2 are parte of a bifold potentiometer. They ascendancy the top tones and bass. There is no accident of overdrive in circuit due to the acquiescent attributes of the complete control.
P3 controls the aggregate of the arresting fed to se additional allotment of the circuit (IC1b) which functions as an operational amplifier.
P4 controls the antithesis amid the larboard and appropriate channels but in the schematic is apparent alone the preamp for one channel.