I have decided to venture into multi-channel. I was concerned about implementing multi-channel without the high cost and complexity of separate discrete amplifiers. I was also concerned about the ability of any H/T receiver I purchased being able to drive the Martin Logan Theos speakers as well as my Bryston amplifier.
Last week, I took the proverbial by the horns and I purchased a NAD T757 multi-channel amplifier. I'm not a big audio visual receiver fan, but the NAD appealed to me because it lacks the usual bells and whistles associated with home theatre components.
Inserting the NAD into my system was easy. I have no center channel speaker, but I had previously purchased a pair of Martin Logan FX2 dedicated surround speakers. These speakers feature an aluminium cone woofer and 2 folded ribbon tweeters. They come in any color you want as long as it's black. I had placed them on rear shelves and the connecting cables were already in place, so it was a case of simply connecting the wires to the amplifier. I ran a tape measure to check the distance from the listening position and I used a Radio Shack spl meter to calibrate the levels and I was ready to listen.
The amplifier is rated conservatively at 60 watts per channel with 7 channels driven, and around 110 watts per channel with only two channels driven. So power is not an issue. The sound quality is surprising when driving the Theos speakers. I expected the normal shrill reproduction of the average H/T receiver but instead I was pleasantly surprised by the smooth, punchy sound similar to my reference Bryston B-60R. I think my Bryston sounds a little more spacious and 3 dimensional, but there's not a lot in it. The NAD drives the Theos to very high levels and doesn't even break into a sweat. I measured spls at my listening position of around 107 to 110 dB 'C' weighted and there was no sign of break-up or distortion. The amplifier was barely warm to the touch (Man, the Theos can go loud!).
Oh, did I mention? I bi-amped the Theos, utilizing the two back channels of the NAD. There's a simple option which you can select from the NAD amplifier setup which allows bi-amping. Frankly, I haven't tried the NAD without bi-amping the Theos. It sounds so good, I am happy to leave it the way it is.
I have a Sony BDP-S580 universal disc player which outputs SACD via HDMI cable. The player converts the dsd signal internally to 192/24 bit PCM. The sound quality is very good, although not quite to the standard of a dedicated SACD player with analogue outputs. I have several multi-channel SACD discs and these have not left the player in several days. I will be purchasing more as finances permit.
Listening to vinyl is also very rewarding. As I mentioned earlier, the sound is not quite to my preferred standard for vinyl and CDs, but it's a lot better than I expected. If I'm being really honest, there also might be a little biais on my part against the sound of the NAD. I naturally expect a dedicated audiophile amplifier to sound better than a H/T orientated component - so it does (whether or not it actually does is another matter - if you get my drift)
I am happy with my purchase. The cost was relatively low, and I have a backup 2 channel amplifier if required.