I've gone through three NAD T773's which all exhibited excessive hiss (separate circuit, through a line conditioner, with all other circuits turned off so it was not the house power).
I decided to go with separates and got the NAD T973 amp. The amp itself is working okay with no hiss from the speakers (though I've heard crackling a few times through the speakers so maybe not). However, its fans are very loud. They are much louder than the T773 fans. I can not only hear them from the listening position, I can hear them easily in the next room, with the cabinet they are in shut (it does have an open back). SPL meter shows 52 decibles from just the fans, a bit in front of the cabinet.
So, I've given up on NAD. The sound is great, but the noise floor, be it from hiss or fans is too much.
However, I would love to find an amp with a similar sound and at least some of the NAD warmth. I'll be driving the amp with a Rotel RSP-1068 and it will be hooked up to Dali Evidence speakers.
So, any suggestions for NAD type 5 or 7 channel amps that won't cost much more than the T973?
I'm currently looking at Parasound, B&K, and Adcom but don't have any experience with them.
You may not wish to contact NAD again, but "SPL meter shows 52 decibles from just the fans". That is an absurd and completely unacceptable level of noise. Even video projectors never reach anything like that. Your amp cannot possibly be up to specification: read the S/N ratio and subtract 52. Fans should only come on as a safety measure. Good ol' silent convection is the way to dissipate heat from audio gear .
The fans alway come on, even with no inputs plugged in, after about 10 minutes. The unit never even gets warm so I don't think the fans are coming on as a safety measure. The T773 fans were on all the time but were quite quiet.
Since I can hear something loose rattle inside the amp when it is tilted, I'm assuming the issue may be more than just the fans.
You are likely right, and I could probably get it replaced for another T973. But this is four unnacceptable NAD's in a row, over a period of four months from my initial order. The last wait for a replacment took a month, without music. I'm not going to go through this again. Or at least if I do, it will be with a different company <g>.
Does nobody have comments on the Sunfire amps? Parasound Halo?