Typically NAD has been all about delivering the best possible sound for the least possible money. As a result, they are not built all that tough and I think you are taking a risk that a used component might fail before perhaps another brand. There is plenty of older NAD stuff chugging away out there, but they had to cut corners somewhere to deliver the great sound per price point (their newer entry level amps have plastic face plates). You already own and NAD and so are familiar with the smooth and natural "house sound".
Cambridge Audio gear is probably only slightly more robust than NAD on average, although the new CA Azur line is physically imposing with thick aluminum face plates, solid chassis and "how did they do that for the price" circuitry. If you decide to buy a used CD player from this mark I would opt for the 540C and 640C Version 2's which are more musical and less noisy than the Version 1's, or get one of the older D500's. Their integrated amps have been uniformly good, providing a little more punchy sound than the NADs.
Rotel equipment has been considered a step up from the other two brands in terms of price and build quality, but not always sound quality. Their amps provide a neutral and very solid foundation for any system with conservative power ratings - a 60W rating should give you all of that and then some. Their CD players are OK, but sound a little dry to my ear. I would think Rotel's approach to overbuilding would serve well when looking at used gear.
Again good luck. If any city in the U.S. besides LA and NY were likely to have some decent stereo stores with clients and sales people who know and care about music production and reproduction, it would probably be Nashville. Take some of your favorite music to the stores in your area and listen to some expensive gear to get a frame of reference. Then listen to some the more affordable gear to get an idea of what you like, what you can expect at that price point, and what brands and models you prefer. My guess is that somebody carries NAD, Rotel and Rega.
Lastly, if you want to look into a new cartridge for your Dual, take a look at this site:
http://www.needledoctor.com/
Cambridge Audio gear is probably only slightly more robust than NAD on average, although the new CA Azur line is physically imposing with thick aluminum face plates, solid chassis and "how did they do that for the price" circuitry. If you decide to buy a used CD player from this mark I would opt for the 540C and 640C Version 2's which are more musical and less noisy than the Version 1's, or get one of the older D500's. Their integrated amps have been uniformly good, providing a little more punchy sound than the NADs.
Rotel equipment has been considered a step up from the other two brands in terms of price and build quality, but not always sound quality. Their amps provide a neutral and very solid foundation for any system with conservative power ratings - a 60W rating should give you all of that and then some. Their CD players are OK, but sound a little dry to my ear. I would think Rotel's approach to overbuilding would serve well when looking at used gear.
Again good luck. If any city in the U.S. besides LA and NY were likely to have some decent stereo stores with clients and sales people who know and care about music production and reproduction, it would probably be Nashville. Take some of your favorite music to the stores in your area and listen to some expensive gear to get a frame of reference. Then listen to some the more affordable gear to get an idea of what you like, what you can expect at that price point, and what brands and models you prefer. My guess is that somebody carries NAD, Rotel and Rega.
Lastly, if you want to look into a new cartridge for your Dual, take a look at this site:
http://www.needledoctor.com/