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Check your Myth

"The signal source sees an impedance equal to the sum of Rx and Ry and for a given signal voltage, a given current will flow through Rx and Ry. As per Ohm's Law, there will be a voltage drop (Vx and Vy) across each resistor as a function of the current divided by the resistance."

Well really the signal soutce will see an impedance equal to the sum of Rx, Ry, and the total impedance of the next stage.

As you can see, the voltage drop Vx across Rx, the "single extremely high quality resistor," isn't even seen by the input that the attenuator is driving. Instead, the input sees only the voltage drop Vy across Ry, the shunt element, the one which the proponents of shunt attenuators claim doesn't matter so much in terms of quality.


However as can be seen, the quality of the shunt element matters every bit as much as the series element. And even though the voltage drop across the series element Rx isn't seen by the input, the current flowing through it must also pass through the shunt element so any deviation from the ideal of the series element will also manifest itself across the shunt element by way of Ohm's Law."

No the the imput "sees" the current that passes through Rx ONLY. Current that passes through Ry is shunted back to the source or ground. Now I am not saying that quality parts are not needed, just trying to help you understand why some feel Ry can be of a lower quality.

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