I looked into just this thing quite a while ago so I can't say for certain whether the cables or driver rules have changed since then.
This must have been from early 2014.
Back then, there was indeed a way to do it. You had to patch the game, find good shielded audio cables, and spend some time tinkering around with your settings to make it work well enough. I did it, it functioned, but it was never very good. The patch took one of my mic inputs on a nice sound card (sbx) and some standard adapters, plus a little bit of faith.
You're not doing any of that on the PS4, please don't even waste your time.
For PC though, it has been done and can probably be done again, unless ubisoft has patched away the ability for the little hack to work. That wouldn't surprise me.
http://www.alessandrogonella.com/2013/02/how-to-play-rocksmith-without-the-real-tone-cable/
http://www.alessandrogonella.com/2013/10/play-rocksmith-2014-without-real-tone-cable/
[–] go1dfish 0 points 4 points 4 points (+4|-0) ago
Not really, in addition to being a basic 1/4" -> USB sound card, they serve as a DRM dongle for the game.
I've had my cables since the original without issue though, use them for some basic recording as well. Sorry you've been having shitty luck.
[–] Drakinor [S] 0 points 1 point 1 point (+1|-0) ago
Well at least there is hope that maybe somehow I can get one that lasts haha. I was afraid that flat piece on the end was effectively DRM.
[–] go1dfish 0 points 2 points 2 points (+2|-0) ago (edited ago)
You could try taking one of your existing cables and splicing in a regular guitar cable or jack: https://www.youtube.com/watch?v=LpMFs0oMfx4
http://imgur.com/a/wALQY