need help on hooking up vintage preamp

I bought a mcintosh from 10 years ago. it's a c20 preamp and the amp is a mc60. i tried hooking it up in the rear with what looks like rca cables but they aren't. the plug is just a little bigger than a rca but looks like an identical plug. what kind of cable is it and where can i get this? i also have a mcintosh 841 cd player. how do i hook this up to the preamp because this one uses a rca. help!
check out audioclassics at8003212834. they are mcintosh experts. if they can,t answer your question call a mc dealer. since audioclasssics deal with all sorts of mc gear i am sure they have the wires you need also
The C20 is a vintage preamp, and the MC60s are vintage mono amplifiers. They are definately not "from 10 years ago" . . . more like 50 years ago.

But they both use conventional RCA connectors . . . if there's a problem with the fit with your cables, then it's either due to worn connectors on the components, or audiophile cables that have very tight-fitting tolerances in their connectors, or both.

But either way, be very careful with these connectors, especially with modern audiophile (large) interconnects. The ground connection between the connector and the preamp/amp is made simply by the crimping of the jack in place, and they are easy to loosen and mess up (especially after fifty years of wear!).