60Hz hum


Hello,

I have a 60Hz hum and I don't know what to do. I must admit that I am dumber than dumb and I know nothing about nothing so my knowledge is very limited here but I did read about It and tried a few things to, alas, no avail.

A bit of context: My system have been playing for a good 7-8 years without any problem but a few days ago I moved furnitures around and did a bit of cleaning and before disconnecting everything I heard a hum in my speakers that I never heard before. How long is/was the hum present I don't know but my room is fairly small and the system is always on yet not always playing because It is my living/audio/TV room all on one. I am pretty sure I would have heard It by now but I didn't so... Bottom line, not sure since when the hum is there.

Once I cleaned up everything and connect everything back on to exactly the same set up as before the hum is still there. What I did so far is connect/disconnect one component at the time and tried to isolate everything. 

In the end I'd say the hum is coming from the integrated. I disconnected from the power bar, I tried direct to outlet, I changed outlet, I changed outlet with and without the power bar, I even changed room and outlet with the integrated and speakers. I tried left speaker, I tried right speaker, I did tried 2 different speaker cables. Hum hum hum... So I don't think Its neither the speakers nor the speakers cable. My logic tells me that It has to be the integrated. 

Where do I go from here? Is my integrated broken? What do I do now?

Any help would be appreciated.

Thanks!

NAD C315BEE integrated
Totem Arro speakers
Blue Jeans Cable BJC Ten White speakers cable
Monster Cable power bar







simon45

Usually this would be ground loop hum, which can happen any time there's more than one path to ground. So check to make sure everything is plugged into the same outlet.

But it sounds like you do have everything in one. If nothing is connected to the integrated, just the speakers, and you still get hum, then its the integrated.

But its low enough you lived with it for years already. So what's a few more...?

You could try a cheater plug on the integrated and see if that eliminates the hum. 
Bob
@ simon45

Look at the plug on the end of the power cord of the NAD C315BEE. I believe it is a 2 wire 2 blade plug. Correct? No equipment ground pin. The unit has double insulated AC mains power wiring. Class II wiring.
https://www.crutchfield.com/S-OVXHs39hsLQ/p_745C315BEE/NAD-C-315BEE.html#&gid=1&pid=2

Just a guess the hum you are hearing is not a 60Hz hum. It is not a ground loop hum.


Does the hum sound like this?
https://www.youtube.com/watch?v=pf-vULfjYK8

Jim

@jea48

Oh man...

When googling it, I came across the PS Audio website and the 120Hz test there is much higher pitched... Mine sounded more like the 60Hz...

https://www.psaudio.com/ps_how/how-to-find-and-fix-hum/

But now your youtube link sounds like the hum I am getting and similar to the 60Hz of the PS Audio link...

So yes, based on your link, my hum sounds like that.

And yes, the NAD has a 2 blade plug.

I don’t know what all this means but... thanks to you, I was most probably wrong with the correct hum in the first place.

Are the troubleshooting the same for 120Hz?

Thank you Monsieur!


@jea48 

From the same youtube link you gave me I looked up 60 Hz test tone and my hum is definitely a 120 Hz hum...

Apologies to all.

@ simon45 OP

Just a guess, bad electrolytic caps in the DC power supply.



Or a bad diode jea
Simon, I think you are absolutely right. Your integrated needs to be sent in for service. I would send it in to NAD. Or, you can dump it and get something new. 

Mike
Not what I wanted to hear at all...

But yes, browsing further online seem to point to bad capacitors, a known fact with NAD apparently... I've read 250$ for repairs!!!

I won't spent 250$ on a 8 years old amp that I paid 400$ back then...

What happened to the good ol'days when stuff lasted 30 years?!?

I would ditch the bastard in a heartbeat If could afford something new but alas... I am dirt poor!

Humming galore, here I come!

Thanks to all for the help!