recommendation for rca interconnect for deeper bass for dac to preamp

You have a choice. You can either buy another cable, or 2, or 3, or 10, and somewhere convince yourself along the way that the bass is better, maybe you will throw in a cable elevator, or something, and sure, for a day, a week, a month you will be convinced it is ... till it is not.

If you don't have deep / full bass, then cable is not the problem. Period. End of story. What we are talking here is a change that is orders of magnitude beyond what a cable will ever do.  Take your pick:  Amplifier/Speaker issue (possibly, but lowest probability), Your speakers/system just are not up to the task (quite likely), Your speakers and the room as a whole are not up to the task (also likely).

You are looking for an easy solution to a problem, as opposed to facing the problem and fixing it. You are not alone. It is a common affliction amongst audiophiles.

oldhvymec,

17 awg, and high inductance --- not a great target for a cable, but they sure are purdy!

All the twist does is make the wires farther apart (higher inductance) and make the wire effectively longer (higher resistance).

Expect the oil would not do a lot. Already have air around it.

Vinyl (PVC) is the vast majority of wire made. Most plastics are a nightmare to make.