Discrete, passive tone control circuit above does not violate the integrity and depth of sound image of any High-End Complex.
Component selection should be with caution (a deviation from the nominal value not exceeding 0.5%) eliminates the mismatch on the stereo frequency and phase response at discrete points Treble control (left diagram) and LF (right) and small (but sufficient for High-End) depth adjustment Tone (6 dB in increments of 2 dB) allowed to circumvent the main disadvantage of passive regulators - a large (in some controllers to 30 dB) attenuation.
In this case, the signal is attenuated by only 7 dB, which does not however - a tangible deterioration in the dynamic range of the entire audio system. One additional switch Speech Cut allows us to weaken the signal by 5 dB and further to suppress low frequency components below 100 Hz by 3-5 dB. This is recommended for improved intelligibility when listening to speech software. For normal matching the output impedance of the source (preamp) should be less than 1 kW, and the input load resistance (amp) - at least 100K. Passive tone control
