Easy option is to set up one PC or a laptop as a player, and another as a recorder. Pretty much analogue sampling (or digital to analog and sampled back to digital). A hardware method that WILL work.

Using a program to split/record the stream should in theory give better results, but yes either way you are a hostage to the original recording volume. A software method that SHOULD work, and I have no idea what add ons, snap ins, plug ins etc are best to rip content from Youtube.