I have a nad c-352 with wharfedale 9.5 speakers, a rotel cd player, everything linked with good cables, and I also have an old quad 33-303 in almost-new condition. While the nad sounds wonderfully for a built-in amp, when I add the quad to the system, the improvement is spectacular. The vocals with the quads have a much more realistic consistency, all mids are more clearly audible, the lows are deeper and more solid, instruments are more transparent. It's truly impressive to see an old unit with such qualities,
even if the quads seem more powerful than the nad (2x45w vs 2x80w for the nad). You can feel the air moving in the room with the low end of the quad, something the nad can't achieve. That's why I can easily understand the popularity of these units even today!!!