What do you all think of Made in Japan Onkyo, Sony (non ES) and Yamaha CD Changers from 1987-1993 sound and build quality wise? How would they compare to a new Onkyo DX-C390? I just bought a new Onkyo DX-C390 that I am happy with, but with a lack of CD changers available in the new and used (in excellent condition) market, I'd like to have an decent sounding inexpensive backup unit in case this Onkyo breaks. It took me a few months to settle on the new Onkyo DX-C390 and being without a changer wasn't very pleasant, so having a decent sounding inexpensive backup unit temporarily would be great. Some of those late 80's/early 90's changers even had dual DAC's in them (like PCM56P). How do they sound?