Vinyl corrector with tube 6F12P
The device is executed on circuitry without feedback, with direct connection between cascades and minimally possible quantity of elements on a way of a signal. The sound is influenced by all without exception elements, in a sound there are no trifles. Do not overlook, that each detail (especially entrance pentodes) possesses microphonic effect and all mechanical influences, eventually, appear in a sound.
In this corrector the pentode - triode 6F12P with μ=100 is used. Tube requires DC heater current. If DC heating is used and the heater power supply is not floating, but grounded at one side, hum is normally inaudible. Elements R5, R6, C6, C7 are for RIAA correction, with tolerance 5%, no more. Output impedance is high and should be followed with high impendance input line amplifier. If you have low input impedance, add a cathode follower.