Does using same brand cables improve performance?

Agree use the cable best suited to the application. All the same is a reviewers come on. I say Boulderdash!

I have Sophia 1's and had an ARC VS115 with an ARC CD# MKll. I would start with all copper cabling as a starting place (the 110 and the DV-60 are fairly analytical and so are the Sophias) . Live with this until something starts to bother you then try a few different cables in different places and hear what happens. I found it less confusing to start with all cables from one company, then when you introduce another company's cable identifying the difference/change was easier. I always try new cable between CDP and pre first, even if I liked the sound I'd move the cable to between the pre and amp just to hear the difference between the two locations.

You're likely not do much wrong if you go for one brand and more specifically one series of cables and cords to wire your entire system. Having said that, I do agree with the previous posters, to quench the best out of your system, carefully mixing brands and/or series may get you closer to your personal sonic nirvana. In this regard, note that some renown companies will actually manufacture only cords (LessLoss leaps to mind) or no cords at all (e.g. Townshend) or no speaker cables (e.g. Cicable). And sometimes, a manufacturer will actually tell you they introduced a new cable on demand just to be able to offer a full product range, aha... The risk of subscribing to the joyful art of mixing is that you may pile up various unused cables after a while because even if you do audition each new one, there will always loom another you'll want to try (luckily, helpful Audiogoners can mostly be found and be at your service to get rid of such pile ;^).

Experimenting with cables will definitely be a well worn path as there are literally hundreds of options, especially when dealing with seperates. Some applications work better upstream while others work better between the preamp and amp. Mixing and matching is also preferred by most, me included after you become intimately familiar with your sound. However, some swear by same brand throughout - network cables sometimes work better this way. There are also tons of cables that do a fine job at all types of price points - then throw in listener preferences - Wow! Karelfd is spot on - I have a pile of cables that are not in use or see some playing time on occasion - usually when I get bored.

As Mechans stated Boulderdash!! Most people mix and match components made by different audio companies, why would anyone believe that to get the best sound you would need the same cable manufacturer's cables when in most cases the components are from different manufacturers.