HI Rob:
The Omage SS-4R is similar to our ISS4 which is also resistor based but has manual switch for the protection. We usually recommend adding impedance matching volume controls and bypassing the internal protection. When the protection switch is enabled and signal is diverted through the resistors the power handling is cut in half 140 watts to 70 watts. The SSVC4 has the impedance matching volume controls built in (300 watts peak, 150 watts RMS per each) Not only do they do the heavy lifting (protection) they give you additional control for each zone. Plus you have dual source option per zone between source A and B. There is also a manual on/off switch per zone as well. Good match for the ONKYO Receiver. Usually we recommend adding an external amplifier but the ONKYO typically is a high current amplifier that has the current o handle the application.
TL/4862