Synergistic Research Foundation Cables

You can expect the sound signature to "mellow" over the course of a few weeks/month (depending on how often you listen). It will retain all the details, but will sound less "sharp".

Thanks. With my tube integrated I’m finding the sound to be grainy and dry. I’m pretty sure that’s not their sound signature so will give it time to break in.

I believe Synergistic offers 30-day money back. I would run them in for 2 weeks and bail if you’re not happy. “Grainy and Dry” is not a very good sign, but do give them 2 weeks at least. 

Had a pair of SR Foundation interconnects in XLR version borrowed from The Cable Co. landing library. They were fully broken in. The sound you’re describing is what I heard in my system as well. Grainy and dull. Hope the speaker cables change for the better after couple of hundred hours for you but I kind of doubt it.