Wouldn't do it. Too many unkowns to say what would happen. You're essentially adding a capacitor across the amp's output. Depending on the capacitance the amp may not like it. However large or small, you're asking the amp to drive an additional needless capacitive load. At the least you're affecting frequency response somewhere. Likely that your evaluation of each cable would be scewed also because of the additional capacitance that wouldn't be there otherwise.
Cheers!
Robert
RSAD
Cheers!
Robert
RSAD