Name 1 Cable in your system you could not live w/o

In other words , you currently own it , and it would be the last one you would consider ever selling. Im my case , In my system, I would say My Ridge Street going from my CDP to Pre. Feel free to nominate a power cord if you feel stongly about it. Of course synergy plays a stong part, but what the heck, its a fun question , Thanks.