In older amps usually have a phono input is available. Today, it is used less and less, and therefore it would be useful if the input can be. Used as line input With this circuit it is. the circuit is actually an attenuator and a filter. The signal is attenuated to the level of a phono-receiving element, and filtered to the RIAA equalization is undone in the amplifier. On 'in' is the line signal, and is connected to the phono input 'from' the amplifier.
- R1 = 1 M 1%
- R2 = 82% 1 K?
- R3 = 1 k 1%
- C1-C4 = 1 nF 1% Styroflex
