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Discussion Starter · #1 ·
Was considering an NAD T752 receiver, but a little hesitant because of some complaints regarding the fan being too loud / on alot. Sent an email to the company - recieved following reply (which I got permission to quote).

Thought this might be of some interest to others who had similar concerns:

> Dear Dr. Drake,


> I am sorry someone hasn't replied more promptly to your question. Our

> Webmaster, Mr. John Milder, passed away very suddenly in November, and we

> are all scrambling to fill in until we can find sombody to try to fill his

> very large shoes.


> Regarding the fan noise issue for the T752, there were some early


> units with improperly adjusted fan circuits that caused the fan to run at

> full speed much of the time. This is not typical behavior. In fact we


> quite shocked when we started receiving these comments, because most of us

> at NAD had never heard the fan operate EVER on our beta test units. Only

> the Lab engineers, when doing high power measurements and reliability

> testing, had the fan running. With normal program material it is very

> difficult to get the fan to run (4 Ohm speakers with compressed disco


> playing at +100 dB SPL it takes about 10 - 15 minutes before the fan kicks

> in, and then the fan runs for less than 1 minute when the music is turned

> down). We now know that some units were shipped that would start running

> the fan after about 30 minutes even with no signal playing - clearly not


> way we designed it, but not something that showed up in our normal

> production QC checks.


> Why do we use a fan? Because we rate our power honestly with all channels

> driven, full bandwidth, and we allow 4 Ohm speakers to be used with most

> models. With a T752, this means that over 400 watts must be dissipated in

> the output stage under certain operating conditions. To do this without a

> fan would require a unit about 3 times the physical size, and obviously


> more expensive, with no real consumer benefit, since 99% of our customers

> would never achieve this "worse case" condition.


> The T742 does not use a fan. It is rated at 50 watts per channel, all

> channels driven simultaneously 20Hz-20kHz at 8 Ohms. We do not recommend


> Ohm speakers with this model, because there is no fan, although like all


> amplifiers this model is fully stable at even 2 Ohms loading.


> Again, our apology for not answering more promptly, and I hope this reply


> helpful in making an informed purchase decision.


> Best regards,

> Greg Stidsen

> NAD Electronics
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