NAD T-775 value

[rrleesb]

I have a NAD T-775 that has three blown channels on one of the amplifiers (front right, center, and surround left). I'm not real sure how that happens, lighting maybe, but it is going to cost $450 to repair with components or $850 to replace the amp. I have since decided to replace the unit with an Integra 50.4.

My questions, what is the value of the receiver for parts or should I just scrap it. Shipping is 50 bucks to get it back.

Also, I want to ensure that I don't have any shorts on my speakers before I hook the new unit up. What should my resistance results look like? I have a PSB imagine set and the Supersonic 10 sub.

 

[rrleesb]

I did resistance checks on all of my speakers and the results are:
FR 5.5 ohms
FL 5.4
C 5.6
SR 5.9
SL 5.9

Garage 6.3
6.3

Deck 6.0
6.0

Do any of these values look out of order?

 

[3db]

I did resistance checks on all of my speakers and the results are:
FR 5.5 ohms
FL 5.4
C 5.6
SR 5.9
SL 5.9

Garage 6.3
6.3

Deck 6.0
6.0

Do any of these values look out of order?

Welcome to the forum. I'm sorry to hear about your NAD. I maybe inclinded to get it fixed because for the price of repair, you won't find anything that comes close to the power delivery of this unit. I'm a little shy of Integra because they are manufactured by Onkyo. Onkyo's customer satisfaction rating is very VERY low and failure rates of their products are at a level higher than even NAD.


How did you measure the resistance? If you used a multimeter (volts/amps/ohms) , then all you measured was the dc resistance of the driver windings and the windings of the crossover. You neglected to take in effect the frequency dependent components and behaviours of the capacitors, driver and cross over windings. That cannot be measured with a simple multimeter.

 

[PENG]

I did resistance checks on all of my speakers and the results are:
FR 5.5 ohms
FL 5.4
C 5.6
SR 5.9
SL 5.9

Garage 6.3
6.3

Deck 6.0
6.0

Do any of these values look out of order?

If you used an accurate multimeters with good batteries and negligible leads/contact resistance, I would expect the d.c. resistance of the imagine speakers measured at the binding posts to be 4 ohm or slightly less. No sign of shorts though, again, assuming you did it right.

 

[rrleesb]

If you used an accurate multimeters with good batteries and negligible leads/contact resistance, I would expect the d.c. resistance of the imagine speakers measured at the binding posts to be 4 ohm or slightly less. No sign of shorts though, again, assuming you did it right.

I measured the resistance values with a Fluke 87 multimeter. On the two front speakers there are two sets of leads for driving the highs and lows separately but I am using the factory supplied "bridge" that drives them together. When measured separately the highs have a much higher resistance and the lows have the lower measured value, combined they have the value of the lows...not sure if that means anything, but that was my results.

 

[PENG]

I measured the resistance values with a Fluke 87 multimeter. On the two front speakers there are two sets of leads for driving the highs and lows separately but I am using the factory supplied "bridge" that drives them together. When measured separately the highs have a much higher resistance and the lows have the lower measured value, combined they have the value of the lows...not sure if that means anything, but that was my results.

The Fluke 87 is fine and if the factory supplied "bridge"/"Links"/"jumpers" are tight that will be fine too. If you measured with the "bridges" removed, you will get different readings between the two sets of terminals because the crossover networks will no longer be tied together in parallel, that is normal. I still think the readings you got seem high as those PSB speakers are rated 6 ohms nominals with dips to 4 or less ohms for sure, that's why I expect the DC resistance to be 4 ohms or less.

I still don't think your speakers are shorted (highly unlikely anyway) and I don't know why the NAD blew 3 channels. Can you provide more details as to what led to the failure, like did you do anything funny just prior? Was the unit well ventilated, how loud do you listen etc...

With due respect and hope you don't mind me asking, you do not seem to know too much about the electrical stuff, how come you own a Fluke 87? Again, sorry but I am curious.

 

[rrleesb]

I still don't think your speakers are shorted (highly unlikely anyway) and I don't know why the NAD blew 3 channels. Can you provide more details as to what led to the failure, like did you do anything funny just prior? Was the unit well ventilated, how loud do you listen etc...

With due respect and hope you don't mind me asking, you do not seem to know too much about the electrical stuff, how come you own a Fluke 87? Again, sorry but I am curious.

I have a pretty good understanding of electronics, I work on radars for the Navy for a living.

I'm just trying to ask people that are more familiar with this area than I am.

I use my receiver for general surround sound use and listening to music around the house and in the garage(zone 2). The receiver had good ventilation, 4 inches on all sides, around it. I originally sent the receiver to get repaired because the display was working intermittently and the techs couldn't isolate the fault. When I got it back the display worked for about a month then the intermittent display fault returned. Shortly after the zone 2 stopped working and then it smoked. Evidently the tech contacted the factory and they were as baffled as he was about the fault. The reason I was doing the resistance checks was to ensure that all of my wiring was good and the speakers were not shorted as a result of a lighting strike(what the factory thought was the cause). I have all of my speaker wires tinned and am using a good quality wire for my in ceiling runs.

 

[slipperybidness]

I have a pretty good understanding of electronics, I work on radars for the Navy for a living.

I'm just trying to ask people that are more familiar with this area than I am.

I use my receiver for general surround sound use and listening to music around the house and in the garage(zone 2). The receiver had good ventilation, 4 inches on all sides, around it. I originally sent the receiver to get repaired because the display was working intermittently and the techs couldn't isolate the fault. When I got it back the display worked for about a month then the intermittent display fault returned. Shortly after the zone 2 stopped working and then it smoked. Evidently the tech contacted the factory and they were as baffled as he was about the fault. The reason I was doing the resistance checks was to ensure that all of my wiring was good and the speakers were not shorted as a result of a lighting strike(what the factory thought was the cause). I have all of my speaker wires tinned and am using a good quality wire for my in ceiling runs.

So it seems like this unit has always been a little bit shady. That sucks. So you sent it in under warranty for the screen and they sent it back without repairing it???

 

[rrleesb]

It was past the warranty period, spent $50 bucks shipping it there $75 diagnostic fee, and $50 shipping it back(un-repaired). Recently I just went through the same pattern... ugh!

 

[slipperybidness]

Soooo....you already put $175 into it to find out "we can't help you"??? WTF???

If this were me, I would be pissed! That was an authorized NAD service center??? They couldn't find the problem and still charged you $75?

Probably too late now, but if you payed with a credit card, I would be contacting my CC company and cancel the payment. Otherwise, at the VERY least, contact the Better Business Bureau local to that service center and file a complaint.

With these revelations, my advice is to stop putting $ into it and invest in a reliable brand like Yamaha.

 

[rrleesb]

I have decided to not repair the unit. It's unfortunate, because I was very happy with the performance. I really don't know what caused the issues but it is frustrating to spend so much money just to not get it repaired.

I don't think there was any malicious intent from the repair company. The display fault would go away if it was unplugged for an extended period of time and not reoccur for quite a while. They said that they left it plugged in for a month and it was still working(I was deployed to Afghanistan). I did however send it to a different authorized repair center after it smoked.

 

[slipperybidness]

Well, I've seen people say it before, so I'll repeat it for your benefit

NAD = "Not Always Dependable"

Which sucks because I agree that I have been impressed with the bang for the buck and SQ from NAD.

 

[Pyrrho]

I recommend getting a Yamaha receiver. From reading threads online and from other sources (one of my brothers repairs electronics for a living), no one seems to make more reliable receivers than Yamaha.

Now, if you are playing your music very loud, particularly for long periods of time, you might want to consider buying a receiver with preamp outputs and using a separate power amp for your speakers. Or just for the front speakers.

 

[PENG]

I have a pretty good understanding of electronics, I work on radars for the Navy for a living.

I'm just trying to ask people that are more familiar with this area than I am.

I use my receiver for general surround sound use and listening to music around the house and in the garage(zone 2). The receiver had good ventilation, 4 inches on all sides, around it. I originally sent the receiver to get repaired because the display was working intermittently and the techs couldn't isolate the fault. When I got it back the display worked for about a month then the intermittent display fault returned. Shortly after the zone 2 stopped working and then it smoked. Evidently the tech contacted the factory and they were as baffled as he was about the fault. The reason I was doing the resistance checks was to ensure that all of my wiring was good and the speakers were not shorted as a result of a lighting strike(what the factory thought was the cause). I have all of my speaker wires tinned and am using a good quality wire for my in ceiling runs.

Time for a new one, something like the Denon AVR-4311 offers just as much power and at least 10 lbs lighter plus you get Audyssey XT32 instead of XT, all for only a few hundred more than the amp replacement for the NAD.

 

[3db]

Well, I've seen people say it before, so I'll repeat it for your benefit

NAD = "Not Always Dependable"

Which sucks because I agree that I have been impressed with the bang for the buck and SQ from NAD.

Onkyo isn't fairing much better than NAD.. just sayin

 

[3db]

I recommend getting a Yamaha receiver. From reading threads online and from other sources (one of my brothers repairs electronics for a living), no one seems to make more reliable receivers than Yamaha.

Now, if you are playing your music very loud, particularly for long periods of time, you might want to consider buying a receiver with preamp outputs and using a separate power amp for your speakers. Or just for the front speakers.

+1 and from what I've been reading on the AVS forum, The "Official" Yamaha AVENTAGE RX-A1030, RX-A2030, RX-A3030 and CX-A5000/MX-A5000 Thread,
YPAO on the upper models are getting high scores for their room eq results