Sound of cables breaking in?

@tommylion - as others have posted what you have experienced is quite normal.

I've had cables that required over 120 hours to start sounding good again and after that they got better, but sounded their best at around the 350 hour mark.

It depends on many factors including metallurgy of the conductors, insulation used and the cable geometry - i.e. how the conductors are aligned within the sleeve.

I tend to install them on a system and then stream music from the internet for about a week before listening seriously.

I've also experienced it with connectors and plugs, so it applies to most things in the audio chain.

Hope that helps - Steve

Cables take at least 100 to 300 hrs to break in this depends on the thickness and the design.When cables are shipped i just had my cables (Purist) re terminated to balanced from rca they will take 20 to 50 hours to settle back in the system.When they are settled in the sound will get smoother with better depth and bass.I can say this balanced cables between the amp and preamp are much more dynamic with more powerful bass as well.Thanks hope this helps. Enjoy!!

These days one can use a USB stick with some tunes on it, even on an old DVD player (with USB input)..and burn that cable in, via playing music signals from the USB/DVD player, into a unused input on your given rig. Let that sit for days at a time, and then the burn in in is done..

So one does not have to waste precious hours on cartridges, or tubes or whatnot. One does not even have to hear it break in. Let the USB/DVD 'burn in rig' play 24/7 for 3-4-5 days..and then you are done.

One can also use specific burn in signals, like pink noise, left running on repeat, off that USB stick.

So, equipment required: One of the ubiquitous USB sticks, an old DVD player with USB input, an input L-R pair on your rig, and the mental wherewithal to get the tunes or burn in signals on the USB stick and make it (the DVD player) run on repeat.

yep, I have experienced all of the above.  Good out of the box, then they got shouty, loud, hard, grainy, or unbalanced, then good again.  I have had bad sounding out of the box, then they got progressively better. 

Another technique that can accelerate break-in is using a Purist Audio Design Ultimate System Enhancer disc.  They claim that for every hour played you achieve 5 hours of music play break-in.  I use that disc to help with burn-in  anything new in my system, including tubes.