For those of you not familiar with NAD, it is a British company that’s been around since the 70’s and they are known to create spartan, relatively affordable, yet musical home audio electronics. You could say that they’re about the same level as Rotel in terms of price and performance. The T975 is a 7-channel x 140W amplifier and the T175 is a Tuner/Preamplifier. Both are in their current product lineup (at the time of writing) and they’re a recommended match for a home theater setup.
The T975 amplifier is a monster. NAD claims it can drive all seven channels with 140 watts simultaneously and continuously. Those running conditions will fry a typical Onkyo receiver. I haven’t tried pushing the amp this hard, but the sheer weight of the amp alone is enough to convince me that the T975 is up to it. Peeking through its top cover, you will notice a mammoth transformer, and three huge fans to cool its output transistors. This amp is all business. It employs a headroom circuitry called “Power Drive” which basically allows the amp to handle dynamic transients. In lay man’s terms, it has a buffer of power for those movie explosion sound effects. I’ve watched some movies with this amp and I would say that it definitely delivers the goods. Somehow, the explosions and gunshots sounded snappier and more alive (compared to a top of the line Onkyo receiver). The amp definitely helped extract the full potential of the speakers connected to it. Playing music was more, er, musical, with a fuller tone and a neutral, less harsh treble.
The T175 pre-amp has all of the features one needs in a home theater: HDMI inputs and output, 7.1 channels, all the essential versions of Dolby Digital and DTS, as well as the (now) all important Audyssey auto-calibration system. True to being a typical NAD, it has no additional bells and whistles, but I would assume that contains top quality components and processors. It’s distinct advantage (again, over an Onkyo receiver) is that it seems to generate a more realistic surround imaging. The “movement” of the sound from front to back and side to side is more distinct and prominent. Although there seems to be a side effect to this: at times you can localize and point out which speakers the sound is coming from. Ideally the sound should seem like its everywhere and coming from nowhere.
To sum up: I was never really convinced that separate amp and pre-amp systems have a distinct advantage over receivers, but the NAD definitely changed my opinion. Amp and pre-amp separates are indeed better, specially in terms of power delivery and dynamics. Separates are worth the extra cost, more so if you have a “serious” set of speakers to go along with it. Separates will give a “full-on” theater experience that can’t be had with receivers.