Lol! What a crock! Salesman is right, he is selling you not helping.
If you really are running the stock crap patch cords that come with components then yes, anything and everything will be a major improvement. But do not just buy the first thing you hear- and definitely do not buy anything from that salesman, or any other for that matter who tries to tell you anything even remotely similar. Also don't buy based on technical BS, engineering or design BS, or anything other than what you yourself hear.
Speaker cables, interconnects and power cords are components in their own right. They don't need to be the same brand any more than your amp and turntable, or speakers and power conditioner.
With all components but especially cables you should never buy what you haven't heard at home in your own system, or at least not without a 30 day no questions asked return policy. Even then never buy what sounds the best until you have tried several contenders. Especially with cables. There are so many and the range between merely good and outstanding, you won't believe until you hear it for yourself. Which will never even happen unless you try a lot.
If you really are running the stock crap patch cords that come with components then yes, anything and everything will be a major improvement. But do not just buy the first thing you hear- and definitely do not buy anything from that salesman, or any other for that matter who tries to tell you anything even remotely similar. Also don't buy based on technical BS, engineering or design BS, or anything other than what you yourself hear.
Speaker cables, interconnects and power cords are components in their own right. They don't need to be the same brand any more than your amp and turntable, or speakers and power conditioner.
With all components but especially cables you should never buy what you haven't heard at home in your own system, or at least not without a 30 day no questions asked return policy. Even then never buy what sounds the best until you have tried several contenders. Especially with cables. There are so many and the range between merely good and outstanding, you won't believe until you hear it for yourself. Which will never even happen unless you try a lot.