Cambridge - 540A /640A ver. 2 Integrated Amplifier

I have the 540V2 in a downstairs basement system driving some KRIX equinox bookshelf speakers. Sounds excellent. 60w per ch. Plenty of power. Save $ and get the 540v2. Seems to be very well built/very high quality. I'm not sure how it would stack up against your NAD. (My feeling is that it may be slighty a better amp, but a lareral move nonetheless.) They are on sale so you would have very little to lose. Good Luck!

I'm pretty happy with my 540, V2 in a second (video) system. In fact, I drive Merlin TSMs with it! It is not nearly as refined as my far more expensive electronics, but it is inexpensive, serves the purpose well, and gives me tone control flexibility I need in this particular system.

Good luck.

I recently picked up a 540A, 540C, and a pair of S30 bookshelf speakers for my girlfriend and I'm surprised how good it sounds.

From what I know, there is no comparison between the 540 and 640. Completely different components and build. Not to knock the 540 but I'll bet the 640 will crush it.

"From what I know, there is no comparison between the 540 and 640. Completely different components and build. Not to knock the 540 but I'll bet the 640 will crush it."

I'd actually bet the 540 sounds better. The 640 has more power (100 vs 60) and yet weighs about the same as the 540 (as I recall). That means the power supply in the 540 may be bigger relative to power output. In addition, *every thing else being equal*, lower-powered amps will generally sound better. This assumes, of course, that the power output is sufficient for one's speakers. Finally, power costs money, and the 640 is not *that* much more expensive than the 540.