If the phono pickup is open circuit, (disconnected from the preamp, or with a very, very high input resistor) it will produce voltage. Since the circuit is open no current will flow. Motion of the stylus is resisted only by its mechanical compliance.
If the phono pickup circuit is closed by a reasonable resistor value (say 47K) the voltage will cause current to flow. The current is dissipated in the resistor and that is power. This power is generated by the pickup, and power generation requires that work be done. In this case the work is the force that the stylus exerts against the electromagnetic force generated by the current flowing through the pickup coils in the pickup magnetic field. The stylus becomes less compliant. Thus, the loading resistor in the preamp affects the mechanical properties of the stylus, with obvious impact on sonic characteristics.
The pickup is a pretty wimpy generator and can't put out much current. When the resistor value is lowered, and more current is drawn, the pickup voltage will decline. When this happens the sound volume will decrease. This is from a purely electrical point of view. I suppose that the changes of stylus mechanical characteristics might counteract the electrical effects over some small range of resistor values. You can be sure that when the resistor value goes to zero, current will be maximized, but it will be very quiet.
If the phono pickup circuit is closed by a reasonable resistor value (say 47K) the voltage will cause current to flow. The current is dissipated in the resistor and that is power. This power is generated by the pickup, and power generation requires that work be done. In this case the work is the force that the stylus exerts against the electromagnetic force generated by the current flowing through the pickup coils in the pickup magnetic field. The stylus becomes less compliant. Thus, the loading resistor in the preamp affects the mechanical properties of the stylus, with obvious impact on sonic characteristics.
The pickup is a pretty wimpy generator and can't put out much current. When the resistor value is lowered, and more current is drawn, the pickup voltage will decline. When this happens the sound volume will decrease. This is from a purely electrical point of view. I suppose that the changes of stylus mechanical characteristics might counteract the electrical effects over some small range of resistor values. You can be sure that when the resistor value goes to zero, current will be maximized, but it will be very quiet.