NAD 753 hum in both front channels

 

Unregistered guest
I bought an NAD 753 back in January. At first it had a bad hun in the center and left rear channels that was loud enough to hear in the center of the room at normal volume. It went back, and they fixed those hums. Now, I have a hum in the two front channels. I can't really hear it just sitting in the room, but I can hear it when I put my ear up to the speakers. It would not really bother me if all AV receivers had this hum, but they don't. I like the NAD sound quality, but I am not used to hums. What could it be?
 

Silver Member
Username: Landroval

Post Number: 612
Registered: Feb-04
Go to: https://www.ecoustics.com/electronics/forum/home-audio/92714.html
 

Bronze Member
Username: Gatt767

Malta

Post Number: 63
Registered: Feb-04
Not too much listeners stay glued to speakers while hearing a sound track. If you think its a hardware fault, and if its bothering you while sitting at your normal listening position then take it to a repair center the earliest possible if its still under warranty!
On my T762, with no source selected and the sound level set to refernce levels, i can hear a hiss or hum comming out from the speakers but that is normal with all audio equipment! All equipment that I have auditioned, from Pioneer to HK, Marantz etc all emit this sort of noise, nothing to get worried about.

 

Anonymous
 
I disagree. My Marantz 5300 even you turn the volume up to +12db, no hiss will be heard even you glue your ears to the speakers. NAD has a problem recently with the design and can not escape with hiss issue. Read the thread " NAD receiver hiss issue.

RPGRUBER, return your NAD to the dealer and complain!
 

Bronze Member
Username: Gatt767

Malta

Post Number: 64
Registered: Feb-04
Anonymous, sorry to tell you, but I do not have a hum prob in my NAD HT gear.For your info, the T763 is built on the T762! No design probs at all my friend so stay glued with your marantz receiver !!!!!:-)
 

Anonymous
 
You said you heard a hiss on your NAD and that's what I heard too when I auditioned the T743 and T753.I brought these NADs at home and I compared it with my marantz 5300 and I did not hear any hiss from my Marantz. To confirm this I bought a HK 230 and I was given 30 days and I can return it if I'm not satisfied. The same thing happened no hiss from the HK 230.I heard this hiss from the NAD and you were saying that it is normal to all receiver that is why I disagree.This hiss is something like a noise from the power supply that needs to be filtered or a circuit not properly grounded. I am from Toronto Canada and phoned Lenbrook ( NAD owner ) and the technician admitted that there was a problem with the software.Just to let you know guys that there was really a problem with the hiss and it s not normal.
 

Silver Member
Username: Smitty

Canada

Post Number: 122
Registered: Dec-03
Anonymous,

Which receiver do you prefer (H/K 230, Marantz 5300 or NAD T743) as far as sound quality goes?
 

Bronze Member
Username: Ben805

Post Number: 11
Registered: Aug-04
have you guys try any power conditioner to eliminate those noise? also keep any RCA and speaker cables FAR AWAY from the power source/cord, that's more than likely the cause of it.
 

Anonymous
 
Smitty I prefer HK sound with deep bass. NAD has no bass. HK is cheaper by cdn$200.Though both receivers sounded clean and have lots of power.
 

Anonymous
 
Benjamin I tried NAD 743 & 753,marantz5300 and HK 230 at home on the same outlet. ONly the NADs have hiss and I think not a power issue.Power cords are isolated from audio cables so no intreference.FYI
 

Silver Member
Username: Smitty

Canada

Post Number: 124
Registered: Dec-03
Anonymous,

That's funny! I bought a NAD T742 last fall because I found the H/K had no bass and the NAD was C$200 cheaper than the AVR230. I agree though they both sound clean and have lots of power. Enjoy!
 

Anonymous
 
Hi Smitty

I'm talking about the T743 and not the T742.I'm using B&W 601s3. On HK my bass setting was halfway( 12:00 setting) while on the NAD T743 I have to adjust the bass to +6 before I get the best punch which should be 0 when you compared it to HK setting equivalent.Have fun!
 

Gold Member
Username: Kegger

MICHIGAN

Post Number: 1416
Registered: Dec-03
most recievers will have hum or hiss or whatever to a certain degree.

if you have none your one of the lucky few.

generally it's a power source issue or ground "from house" or
cable from cable tv.

to try and find where it's coming from unplug everything
from the unit except speakers and see what you get
if you still get more than what you think is acceptable try a cheater
plug "no groung lug" on the reciever and see what
that does. if you still
get it try a good line conditioner. and other units to see if the
reciever is noisy or just your setup.

once you eliminate the noise try plugging in 1 piece of equipment at
a time and test for noise to find the culprits.
generally it's a ground loop issue that is why many
newer components come with no ground on the cord.
if you look closely at the h/k units you will see inside
the reciever their is no ground conection but the plug end that goes
into the wall outlet that plugs into power has the ground tab to fake
people out. that can be why one system will have
hum plugging into the same
but another will not. so many will blame the humming unit when another
is quieter.

also other high end uits have ground lift switches and plug lifts to
eleviate this issue. while others will conceal the fact they use
no ground so they appear to be quieter.

unless something is seriously wrong it's probably something in your setup.
 

New member
Username: Sound_advice

Post Number: 4
Registered: Sep-04
"Not too much listeners stay glued to speakers while hearing a sound track. If you think its a hardware fault, and if its bothering you while sitting at your normal listening position then take it to a repair center the earliest possible if its still under warranty!
On my T762, with no source selected and the sound level set to refernce levels, i can hear a hiss or hum comming out from the speakers but that is normal with all audio equipment! All equipment that I have auditioned, from Pioneer to HK, Marantz etc all emit this sort of noise, nothing to get worried about."



I Agree with Robert on this one, pretty much all the receivers today will has some form of hiss or noise if no source is selected or paused and then the volume maxed out.
 

Gold Member
Username: Kegger

MICHIGAN

Post Number: 1423
Registered: Dec-03
agreed!

then theirs things you can do to try an lessin it.
 

Silver Member
Username: Johnny

Missouri

Post Number: 400
Registered: Dec-03
FINALLY, THE VOICE OF REASON IS HEARD!!!!
 

Silver Member
Username: Myrantz

Post Number: 619
Registered: Aug-04
Johnny

Could you hear my wife from Missouri?

:-)

Cheers
M.R.
 

Bronze Member
Username: Gatt767

Malta

Post Number: 65
Registered: Feb-04
Come on people we are not talking of thousands of pounds worth of a receiver or a very high end processor tipo KRELL etc. etc. we are talking about receivers with the Price of a good stereo receiver packed to the gills with processors, amplifiers, tuners, video switching cards etc.
 

Silver Member
Username: Landroval

Post Number: 633
Registered: Feb-04
Whatever, but still NAD is the only one with a clearly audible hiss even with low volumes. All the other receivers I've heard including very cheap Sony, Yamaha, Pioneer dont hiss as loudly as these couple NADs I've tried.
 

Bronze Member
Username: Gatt767

Malta

Post Number: 66
Registered: Feb-04
I completely disagree, maybe at Malta we are supplied with low grade equipment. As all the receivers that I have auditioned before going to the NAD all hissed with no source selected with the volume pushed to the MAX. Sorry but cannot agree on this one.
 

Silver Member
Username: Landroval

Post Number: 634
Registered: Feb-04
I was not talking about volume pushed to max. I was talking about hiss at normal listening volumes. NAD hisses, others not so much.
 

Bronze Member
Username: Frank_abela

Berkshire UK

Post Number: 25
Registered: Sep-04
Hey, even my Chord CPA4000/1200E exhibits a little hiss through my very efficient Audio Note AN-Es! Background noise is always there, the level of the noise varies from amp to amp and in my experience is a product of preamp stages rather than power amp stages. Odd that this is the case, isn't it? It shows, however, just how important the processor/preamp stage is to the end result.

Regards,
Frank.
 

Bronze Member
Username: Gatt767

Malta

Post Number: 67
Registered: Feb-04
Not at all landroval, my current T762 with firm ware ver 1.18 does not emit any of the mentioned hissing hum etc. infact today I re went and re checked my NAd, as I thought I was getting deaf and my NAD is dead silent, from the optical ins and the analogue ins. , even with a source selected and the receiver locked onto dd no hiss or hum at all!
 

Silver Member
Username: Landroval

Post Number: 635
Registered: Feb-04
Ok, that's good to hear. Maybe it's a software problem? What do you think?
 

Bronze Member
Username: Persvako

North Europe

Post Number: 45
Registered: Jun-04
Robert Gatt has 7x2 series, it has been said many times to be quiet.

But there are lots of people that blame that we don't understand it's normal receiver hisses. But have you listened these NAD 7x3 series?! that is probably the only series that makes this terrible noise! Try and listen before you tell some theorys...
 

Silver Member
Username: Johnny

Missouri

Post Number: 404
Registered: Dec-03
I have listened to all four receivers in the 7x3 line at one point or another in quiet dealer listening rooms (or at least as quiet as can be expected) and I have heard NO hiss at all. Granted, I didn't place my ear directly to the speaker, but I could discern NO hiss from a normal listening distance at normal listening volumes.
 

Gold Member
Username: Kegger

MICHIGAN

Post Number: 1432
Registered: Dec-03
try all remadies before you blame reciever also.

maybe power cords are different.
maybe older model has no internal ground.
maybe one does it with certin devices attached.

so you need to try with no devices attached and no ground from power cord.
 

Gold Member
Username: Kegger

MICHIGAN

Post Number: 1433
Registered: Dec-03
also if you don't have really good power in your home you need
a line conditioner!
 

Bronze Member
Username: Gatt767

Malta

Post Number: 68
Registered: Feb-04
persvako, I know what i am saying. I've been loyal to this brand from the T750 model. I moved to the T751 and currently to the T762. I went to audition the T773, and this was the first think that I looked into at the Supplier. Besides that when ever upgrading, I also audition other brands. I haven't upgraded to the current T773 series as currently all receiver are based on the 1.22 software and this does not support DPL2x.

So please don't try to generalise that all current Nads have a hiss problem. Just remeber that the current range , especially the T763 and T753 are based on the T762 chassy. Internally NAD have made very slite modifications. As regards to the Power supply section its basically the same as the T762. The difference is in the redesign of the heat sinks, more fans and software upgrade ability throught the Rs232 port.
 

Bronze Member
Username: Ilari72

Post Number: 13
Registered: Apr-04
Johnny,
have you tried T7x3 with headphones?
 

Silver Member
Username: Johnny

Missouri

Post Number: 405
Registered: Dec-03
I have not tried any of the newer models with headphones, only my own T762. I never listen to headphones on my unit, so it never occured to me to audition with them.

 

Bronze Member
Username: Persvako

North Europe

Post Number: 46
Registered: Jun-04
I have tried it without any devices attached without any cables plugged. The same result always. I have tried 2 other receivers in this same place, they don't hiss. I don't know what is this, but it's driving me crazy. Like Ilari72 said, again, the worst is the noise with headphones. I get headache immediately if I try to listen with them. Obviously there are some people having non-hissing units, I don't know.. In that case why don't NAD people fix that problem. They just return the units hissing like before. If there are good working receivers in the market also, why can't they fix that BIG problem!??

I can't know if you are only dealers who want to make NAD's reputation better.. Anyway, I'm pretty pissed of right now, I don't hide it. Sorry guys!
 

Gold Member
Username: Kegger

MICHIGAN

Post Number: 1435
Registered: Dec-03
have you tried with no ground plug on the power cord?

with no devices attached.

because the ground thing is where most get the noise!
i'm not a sales person or nad guy. i'm running harmon kardon and parasound
among others and the ground loop thing usually takes care of it!
 

Gold Member
Username: Kegger

MICHIGAN

Post Number: 1436
Registered: Dec-03
also a line conditioner may be needed.
some units need line conditioners more than others.

but the ground loop thing is usually a bigger problem.
allways when you get noise from an amp or reciever
check for ground loops
by using a plug with no ground and all devices removed.

I can't sress the ground loop thing any more. but
just using a plug with no ground isn't a good test
you have to use a no ground plug and no devices attached.

if after you have done that and used a line conditioner you still get
it than the unit needs to be replaced.
 

Silver Member
Username: Johnny

Missouri

Post Number: 407
Registered: Dec-03
persvako,

I understand your frustration. I would probably be a little ticked too if I had gone through what you have. I am certainly not an NAD rep. Yes, I may be biased on the subject (as I have a perfectly functioning NAD unit), but I just want to make sure NAD is getting a fair deal here. If there truly is a problem, NAD definately should fix it. However, there are many who seem to be unecessarily jumping on the anti-NAD bandwagon here. NAD receivers really are wonderful in my opinion, and I just don't want to see someone turned off to them because a few people have experienced problems.
 

Bronze Member
Username: Ilari72

Post Number: 14
Registered: Apr-04
Theres no ground plug on my NAD T743.
But I have done tests on 3 different rooms in my apartment with and without other equipment. I have even shutted off freezer etc. hiss is there. The only way to get rid of hiss is take 'main in-pre out' jumpers off.
This is the first hissing device for me. Previously I have used Yamaha and Denon, dead silent devices.
 

Gold Member
Username: Kegger

MICHIGAN

Post Number: 1437
Registered: Dec-03
well then if youv'e disconected everything and no
ground but you still have the issue.

their is only 1 thing left.
a line conditioner if that does not do the trick
I would get rid of the unit.

as their is nothing else you can do!

but all i want to get accross is that the hiss and buzz is not just
limited to nad. every manufacturer is suceptable to these issues.
i've had them and have never owned a nad piece of equipment
but just about everything else. rotel/kenwood/parasound
b&k/harmon kardon/pioneer among others and various degrees of noise
that most was taken care with eliminating ground loops and using line conditioners.
 

Bronze Member
Username: Ilari72

Post Number: 15
Registered: Apr-04
Johnny,
I agree with you. NAD receivers really have (at least) wonderful sound. I dont wanna change from NAD to Marantz or H/K but if they cant fix my unit, good bye NAD :-( I think thats reason of pissed NAD owners.
 

Bronze Member
Username: Ilari72

Post Number: 16
Registered: Apr-04
I will buy line conditioner and let you know.
 

Bronze Member
Username: Persvako

North Europe

Post Number: 47
Registered: Jun-04
Great! How much is that by the way?

Yes, I like my NAD very much, OSD is great and also little subtlety that you can change the names for inputs, I like that! But my ears are too sensitive, they can't stand hiss. Great sound, great unit, if I don't hear the hiss...
 

Gold Member
Username: Kegger

MICHIGAN

Post Number: 1438
Registered: Dec-03
if you guys are friendly with a shop in your area
maybe you can borrow one.

otherwise something descent is about $100 u.s.

or they go way upto $1000 for top of the line!
as many systems really need a good one. "or at least could benefit from one"

i'm certainly not saying go spend more than $100.
just giving you an idea
that these things are widely used and beneficial.
 

Silver Member
Username: Billdashill

Post Number: 108
Registered: Dec-03
No ground plug? You're nuts. The wider side of the plug is the ground, if I'm not mistaken. Someone correct me if I'm wrong. Got to have a grounded plug.
 

Gold Member
Username: Kegger

MICHIGAN

Post Number: 1439
Registered: Dec-03
no the ground is the third plug! "many units don't have one"

the wider plug sets polarity.
 

Gold Member
Username: Kegger

MICHIGAN

Post Number: 1440
Registered: Dec-03
hear is a link to one of the better companys of
line conitioners and power regulators.

http://www.richardgrayspowercompany.com/info/about.html

It looks like though now it's about $200 for descent line conditioner
these days. unless you want to spend more and go with richard grey.
 

Bronze Member
Username: Persvako

North Europe

Post Number: 48
Registered: Jun-04
I don't understand what the hecking plugs are you talking about...
 

Gold Member
Username: Kegger

MICHIGAN

Post Number: 1442
Registered: Dec-03
well in the us on the power cord for the reciever
theirs 2 prongs next to each other then a third that
is in between them but down a little, that one is
the ground.

in europe i believe it is simular 2 round posts close to each
other with a third down a little and that one is ground.

anyways if you have 3 prongs that plug into power one is ground.
many units do away with the third prong "ground"
because it's a major source of interference.

so if you don't have 3 that plug into a wall socket than
you don't have a ground.

but if you plug a device into your reciever that has 3 prongs you can induce
the ground loop all over again!
 

Gold Member
Username: Kegger

MICHIGAN

Post Number: 1443
Registered: Dec-03
hear is a link that might help.

http://kropla.com/electric.htm#plugs
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