Dear Brad: For a practical point, If the input value resistor of your phono stage ( no step-up transformer ) is 100 ohms and up you don't be " nuts " for the cable/connectors resistance: *** " just install a 500 ohm resistor . " ***
But if that value is, for example, 10 ohms then you have to worried about the resistance of your cable/connectors and other issues.
Forgeret about the Doug formula. The easy way to combine two or more resistor to obtain some value is: add the two or more resistance values, example: 125+100= 225 ohms, and soldered in serie. That's all.
Regards and enjoy the music.
Raul.
But if that value is, for example, 10 ohms then you have to worried about the resistance of your cable/connectors and other issues.
Forgeret about the Doug formula. The easy way to combine two or more resistor to obtain some value is: add the two or more resistance values, example: 125+100= 225 ohms, and soldered in serie. That's all.
Regards and enjoy the music.
Raul.