Agree with Mr. Gilman. But, maybe because its so early. I dont get the part about needing 2 switchers. Oh, verify the preamp can provide enough current for the old school switcher. Many modern rec or prepros need another relay switching an alternate power source for the switcher trigger. The Niles requires 100mA. A current Marantz prepro provides 150mA. not even enough for a universal auto type relay you find at an auto parts store. Mousser electronics has a good selection.