NAD C 740

 

New member
Username: Mikeyman

Post Number: 1
Registered: Oct-08
Hi there,

I was given a NAD C740, and in hooking it up i found that it wouldn't put out sound. But when i turned it up all the way i got music. I currently have it hooked up to a DVD player and my computer, both out puts are performing the same. I have to turn it up all the way before i get any sound, and even then its very weak, they are running to KEF Q series speakers. It won't let me attach the owners manual, its not been helpful though.
 

New member
Username: Mikeyman

Post Number: 2
Registered: Oct-08
BTW all Source volumes are at Max.
 

Platinum Member
Username: Jan_b_vigne

Dallas, TX

Post Number: 13055
Registered: May-04
.

Let me guess, you want to know what's wrong and how to fix it.
 

New member
Username: Mikeyman

Post Number: 3
Registered: Oct-08
uh... that would be ideal. I guess i didnt say that. If anyone can help me that would be stupendous
 

Platinum Member
Username: Nuck

Post Number: 10959
Registered: Dec-04
Is the tape monitor on the receiver turned on?
 

New member
Username: Mikeyman

Post Number: 4
Registered: Oct-08
no, it did go over that in the manual. It didn't help
 

Silver Member
Username: Jrbay

Livonia [Detroit area], Michigan USA

Post Number: 433
Registered: Feb-08
What does it sound like using the tuner?
 

New member
Username: Mikeyman

Post Number: 5
Registered: Oct-08
same, there is sound, its just really quiet
 

Silver Member
Username: Jrbay

Livonia [Detroit area], Michigan USA

Post Number: 434
Registered: Feb-08
Now THAT tells me something!

So we now know the problem exists with or downstream of the receiver (not the fault of your computer, DVD, or input cables. Next, there are the speaker wires and the speakers to eliminate, done by either hooking different speakers (and wires) to the NAD or hooking the speakers (and wires) to a different amp.
 

New member
Username: Mikeyman

Post Number: 6
Registered: Oct-08
hmmm... thank you. And if you dont have either of those things readily available?
 

Silver Member
Username: Jrbay

Livonia [Detroit area], Michigan USA

Post Number: 435
Registered: Feb-08
headphones???
 

New member
Username: Mikeyman

Post Number: 7
Registered: Oct-08
what about them? I have some. Are you thinking that i should hook them up to the receiver?
 

New member
Username: Mikeyman

Post Number: 8
Registered: Oct-08
when i plug in the head phones the sound works normally.
 

Silver Member
Username: Jrbay

Livonia [Detroit area], Michigan USA

Post Number: 436
Registered: Feb-08
Terrific!!! That is good news, maybe we can now eliminate the receiver. Check your speaker wire very carefully, if the exposed wire going to the receivers terminals is too long it could be shorting the the chassis or crossed with each other. If that isn't it then how old, how long, and how large is the wire?
 

New member
Username: Mikeyman

Post Number: 9
Registered: Oct-08
Firstly THANK you Jim for all of your help so far. The speaker wire is a few years old, it came 2 6' cables and they are Monster Z series cables. I have not found any exposed wires, as they are double wrapped. No they are not crossed, and even if they were it still creates the same sound. Whether it is Red on Red, Black on Black, or Black on Red.
 

New member
Username: Mikeyman

Post Number: 10
Registered: Oct-08
Where the wires are in separate housing it appears to be 10 gauge wiring maybe 8.
 

Silver Member
Username: Jrbay

Livonia [Detroit area], Michigan USA

Post Number: 437
Registered: Feb-08
No problem with the help, it is why we are here I suppose.

So with way overly expensive wire like you have we can probably eliminate that unless (and I failed to mention this prior) it has been crushed somewhere along its length.

There is some high resistance going on somewhere and we are running out of explanations unless the speakers are blown for some reason (assuming they were given to you as well) The next step (without some other speakers to try) is to ask the person you got this gear from if there was a problem with it.
 

Bronze Member
Username: Mikeyman

Post Number: 11
Registered: Oct-08
Well, crap! I talked to him and he said that last time he had it hooked up it worked wonderfully. He was using the same configuration I am using, as far as the speakers and receiver is concerned. I am going to get some other wire just in case that is the problem. The sound that is coming out of the speakers is quite clear, not distorted by any means. But it seams that it is just treble with out any base, and they are 8 ohm speakers connected the way KEF suggests. If you have any other suggestions for trouble shooting let me know.

Thank you,

Mike
 

Silver Member
Username: Jrbay

Livonia [Detroit area], Michigan USA

Post Number: 438
Registered: Feb-08
You just reminded me of another thing:

Are there 4 binding posts on the back of each speaker???
 

Gold Member
Username: Dmitchell

Ottawa, Ontario Canada

Post Number: 1580
Registered: Feb-07
Where ya going with this Jim? You thinking maybe he's missing the jumpers?
 

Bronze Member
Username: Mikeyman

Post Number: 12
Registered: Oct-08
Yes there are 4 binding posts on the back of each speaker 2 hf 2 lf. The input is on the HP with jumpers to the Low on both.
 

Silver Member
Username: Jrbay

Livonia [Detroit area], Michigan USA

Post Number: 439
Registered: Feb-08
DAMN! Yes David that was exactly where I was going! What other obvious thing am I missing?
 

Gold Member
Username: Dmitchell

Ottawa, Ontario Canada

Post Number: 1581
Registered: Feb-07
I'm thinking it's the receiver...
 

Silver Member
Username: Jrbay

Livonia [Detroit area], Michigan USA

Post Number: 440
Registered: Feb-08
Yeah, that is why I said maybe when we moved on to the wires. The headphones work fine though!!
 

Gold Member
Username: Exerciseguy

Brooklyn, NY United States

Post Number: 2068
Registered: Oct-04
Are the preamp jumpers on the back of the receiver missing or loose?

i.e. Are there connectors between the R/L pre-outs and main in?
 

Silver Member
Username: Magfan

USA

Post Number: 351
Registered: Oct-07
this is interesting: I just looked at a backpanel pic of the c740bee.....there are A/B speaker terminals. If there is some leakage, and you are calling for 'A' speakers and are actually hooked up to 'B' terminals, you could get clear, very low levels.
1. Turn off.
2. Turn volume ALL THE WAY DOWN.
2. Speaker wires to 'A' terminals
3. check wiring again...I know you have
4. Turn on at LOW level.
5. let me know if this helped?

thanks for an interesting problem.....
 

Bronze Member
Username: Mikeyman

Post Number: 13
Registered: Oct-08
Christopher! IT WORKS!!! The connection was missing... it was as simple as that! YOU ARE MY HERO! haha *wheph big deep sigh*
 

Bronze Member
Username: Mikeyman

Post Number: 14
Registered: Oct-08
Thank you all who helped me in this seemingly un-solvable problem. All of your help and guidance has really paid off!

Thanks again,

Mike
 

Gold Member
Username: Exerciseguy

Brooklyn, NY United States

Post Number: 2069
Registered: Oct-04
Glad to be of service. The C740 is a GREAT receiver, happy listening!
 

Platinum Member
Username: Nuck

Post Number: 10960
Registered: Dec-04
Attaboy CM!

Gee this is fun!

C'mon back with a hard one, Hilly! hehe
 

Platinum Member
Username: Nuck

Post Number: 10961
Registered: Dec-04
Never mind that the absence of a jumper only admitted the crosstalk of the unit in the first place...
 

Gold Member
Username: Exerciseguy

Brooklyn, NY United States

Post Number: 2070
Registered: Oct-04
...ah yes Grasshopper, but aren't all things in the universe connected in one way, shape, or form?
 

Gold Member
Username: Exerciseguy

Brooklyn, NY United States

Post Number: 2071
Registered: Oct-04
Michael, some day, and that day may never come, I will call upon you to do a service for me. Until that day accept this justice as a gift on my daughter's wedding day.
 

Gold Member
Username: Nickelbut10

Post Number: 1995
Registered: Jun-07
Good call Chris.
 

Bronze Member
Username: Mikeyman

Post Number: 15
Registered: Oct-08
Christopher,

And on that day, may it come soon, you will have it! Congrats to your daughter.
 

Gold Member
Username: Dmitchell

Ottawa, Ontario Canada

Post Number: 1583
Registered: Feb-07
Hey, that's really cool.

Congrats Mr. Exerciseguy!
 

Gold Member
Username: Stu_pitt

Irvington, New York USA

Post Number: 3064
Registered: May-05
As a heads up, the headphone out working had very little if anything to do with if the receiver was working properly or not. The headphone amp is seperate from the power amp. If the power amp section was bad, the headphone section could still work.

Glad to see it all worked out.
 

Gold Member
Username: Frank_abela

Berkshire UK

Post Number: 3243
Registered: Sep-04
Chris,

If it's your daughter's wedding day you should be smashed out of your skull...
 

Platinum Member
Username: Nuck

Post Number: 10963
Registered: Dec-04
And writing checks...

CM, I hope it is a grand and wonderful event for everyone.

Congrats all around!
 

Platinum Member
Username: Jan_b_vigne

Dallas, TX

Post Number: 13057
Registered: May-04
.

"As a heads up, the headphone out working had very little if anything to do with if the receiver was working properly or not. The headphone amp is seperate from the power amp. If the power amp section was bad, the headphone section could still work."


That's true in about 90% of the receivers on the market. Most receivers and integrated amplifiers built in the last few decades have run the headphones from a dedicated headphone amplifier, usually a small 1-2 watt IC based circuit, rather than the actual output transistors of the power amplifier. Not all receivers operate this way but it's quite common in budget - read less than McIntosh priced - products. A few vintage receivers also run headphones from the power transistors of the amplifier and headphones are often placed in line with a "normalized" headphone jack that cuts off the speaker connections when headphones are inserted. It's a good idea to check the headphones when the speaker ouptputs are dead just to make certain the pre amp section isn't causing the problem but working headphones won't tell you much about the power amplifier in most receivers.


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