rotated counter clockwise increases the resistance on the cathode path to ground on v 4 this may limit the amount of current that flows through the tube and may reduce the audio signal by u2212 15 20 while simultaneously raising the dc operating voltage of all forward following dcv power supply nodes this may also reduce the amount of control grid bias voltage lowering the control grid bias voltage in conjunction with raising the dcv operating point of preceding preamp stage gain modules may create greater sensitivity to input audio signals it will be appreciated that the 3 1k value of this portion of the circuit may be created by placing a 3 3k resistor in parallel with the input and the wiper of the variable resistor as the hybridmaster system control is engaged and rotated counter clockwise the perceived audio loudness is reduced due to one part audio signal attenuation and one part current limiting which reduces the phase inverters ability to amplify the signal thus lowering the volume while these two elements work in tandem to reduce the signal level the grid bias voltage of the phase inverter is going down while the operating voltage of the entire preamp section is going up this increases the sensitivity of the entire preamp circuitry in essence embodiments of the present invention are crossfading between states of emphasis de emphasis in separate circuits within the amplifier through research and testing current limiting must be controlled to allow only a variable effective reduction of 15 25 additionally control grid bias must be controlled to allow only a variable reduction of 25 35 beyond that the signal degradation may no longer be acceptable additionally the amount of downstream voltage.