NAD T773 problem resolved. (1 Viewer)

[Kevin. W]

Recapping my issue with my NAD T773:

Unit would exhibit an excess of hiss and hum after sending a signal to the unit via optical from my DVD or cable box. Tried everything to remedy the problem but nothing worked.

After some communication with the wonderful people at NAD I decided to drive down to Lenbrook head office to take the unit in for repair. Got the bright idea during the drive to ask if the unit could just be swapped for a new one since it was still within the 30day purchase window. I figured they would tell me to go through the dealer for that, but wouldn't you know they gave me a new unit. The customer service that I experienced today was above and beyond what I could have expected. As soon as I got the new T773 home, I hooked it up to my setup and all is working perfectly. Now its time to do some serious movie watching.

On another note, while I was waiting for the new unit, I was told that if you only use the receiver in 5.1 mode that you can use the Back L/R channels to bi-amp the front L/R. Since I have the splitters/inteconnects and wire available from my last setup, I think I'll give it a try.

Kevin

 

[Carlo_M]

Any chance you can ask them how the fix was done (i.e. what was the difference between the new and old models)? I have an approximately 10 month old T763 w/ hiss (and had a T762 one which I traded up from that also had it) and am desperately seeking a fix...

Thanks! (wish I lived within driving distance...)

 

[Kevin. W]

I'll fire off an email and ask them if they could let me know what they find out. If they let me know I'll drop you a line. The hiss you get from your speakers, is it loud enough to hear from the listening position or is it only heard with your ear at the tweeter. If its only when your ear is next too the tweeter thats normal because of the toroidal transformer in the unit.

Kevin

 

[Chu Gai]

That's wonderful news Kevin. Now that you have your hiss-free unit, do you think you're losing any fine detail or microdynamics?

 

[Carlo_M]

As in the closed thread (so let's please not go there), it is audible from the listening position, and I have tried everything too: from only 1 source, 1 speaker, all other components unplugged, all digital sources disabled, etc. etc.

There's only 1 way to make my T763 quiet: use it as a power amp. I plugged in my Sony STR-DA555ES via the main-ins in the T763 and it's dead quiet. So no, it's not the toroidal's fault as it would show when the T763 is in power-amp mode. The fault is clearly in the pre/pro section of the T763.

The fact that you got one that was dead quiet (and being in Lenbrook I'd bet it's a newer model, fresh off the assembly line) shows me that they've fixed whatever the problem was.

Thanks for whatever help you can provide! Glad your unit is now 100% satisfying to you (as I'm sure mine will be if I can kill the hiss).

 

[Kevin. W]

Carlo do you know which firmware version you have on your T763? I have version 2.05a if you want it.

Kevin

 

[Carlo_M]

Kevin - that'd be cool but I think firmware v.2 requires a hardware upgrade too, mine is v.1 point something.

How did you get v2? Is it on a CD or on your PC? Just curious.

Do you think a firmware fix is the answer? Just curious...

 

[Kevin. W]

It maybe the answer. I'll send you the firmware via email. I suggest you send NAD an email or drop NAD support a note at the Help center on their website and ask if upgrading the firmware also requires a hardware fix. All you need is your PC and serial cable to do the upgrade. Its dead easy to do.

Kevin

 

[Carlo_M]

Thanks I got the file. however I'm going to hold off because I'm 99% sure that the firmware update requires a chip replacement too, and you can't do one without the other (for all v.1 units).

I'll wait and see what they say, I dropped a line in the new support forum on NAD's site and see what they say.

Thanks for the file, though!

 

[Kevin. W]

Carlo, did you ever hear back from NAD?

Kevin

 

[Carlo_M]

They put me in touch w/ a local authorized repair center but they're swamped. Maybe in a week or two I'll take it in (I'm still in the first year of my warranty so I have plenty of time).

The guy didn't sound like he could fix it though, and has some interesting theories as to the culprit. He was speaking in very technical terms over the phone (and we had like a 15 minute conversation) so when I do take it in to him, I'll try and get some clarification and post it here.

He seems to lay the blame on NAD's design, though, something to do with their volume control section, and did hint that he was not sure something could be done...

EDIT
Oh he did ask me to ask you a question about your new, dead quiet unit. Do you notice that you have to turn the volume higher than your previous unit? i.e. on your old unit you listened at, say, -18 and now you listen at -8?

And do the jumpers at the back of your T773 (connecting the main-in inputs) look the same as your previous unit's jumpers?

Thanks!

 

[Kevin. W]

Carlo, I'll let you know about the volume thing. Hope everything works out for you in the end. If he can't fix it get him to get you a new unit.

Kevin

 

[Kevin. W]

No difference in the volume setting.

Kevin

 

[Kevin. W]

Carlo, Have you taken you unit in yet? Whats the word?

Kevin