Nord One Up Ncore NC500 amps, Class D ready for prime time .....

So far I had troubleshooted as mention below to no avail

* opened the chassis to see if anything has come loose only to find that everything is firm and secure. I found that the buzz is coming from the little transformer in the middle of the NCore power supply unit.
* Disconnected the balanced input on the Nords from the Preamp - still not luck.
* Unplugged everything from the conditioner except the Nords connected - still it buzzed
* Connected the Nords directly to the dedicated wall outlet where everything else is also connected via the conditioner but still with no luck

Anything else that I can try ? So what does it tell us so far ?
 
Devg said:
So far I had troubleshooted as mention below to no avail

* opened the chassis to see if anything has come loose only to find that everything is firm and secure. I found that the buzz is coming from the little transformer in the middle of the NCore power supply unit.
* Disconnected the balanced input on the Nords from the Preamp - still not luck.
* Unplugged everything from the conditioner except the Nords connected - still it buzzed
* Connected the Nords directly to the dedicated wall outlet where everything else is also connected via the conditioner but still with no luck

Anything else that I can try ? So what does it tell us so far ?
Click to expand...

Only other things I can think to try:

1. Use the stock power cord into your wall outlet direct - see if problem remains
2. Take one amp and use the stock power cord into a different wall outlet in your garage or some other obviously different leg of the house A/C panel - see if problem remains
3. Take one of the amps to work (completely different building) with the stock power cord and see if the problem remains plugged in there

If the problem remains after all that, then I'd say there's something wonky with that batch of NCore power supplies.....
 
If you need help drop me a mail. Sounds like we have a rattling transformer. I'm around all weekend.
 
Ok, I quickly tested as Mike suggested.

* use a different power cord - same problem
* use stock power cord - did not help
* tested out in two other outlet in the house which are on different breaker - did not help either

Question: Is the front push button for power or mute operation (as NC400) ? I hear this buzz as soon as I push this button.

I have yet to take this in my office or a friend place to check it out.
 
boggit said:
If you need help drop me a mail. Sounds like we have a rattling transformer. I'm around all weekend.
Click to expand...

Colin, just sent you a mail. My biggest problem at this time is I will be out of country early next week for couple of weeks.
 
Ok, if you try the amps in a different location and hear a difference, let us know. I can send you my pair to try and see if you have the same issue or none at all. Only problem is that it will take a week to get.

Let me know via pm and we can workout details if you want to proceed.



Devg said:
Yes Joe. Not exactly San Jose but the next city Santa Clara.
Click to expand...
 
joeinid said:
Ok, if you try the amps in a different location and hear a difference, let us know. I can send you my pair to try and see if you have the same issue or none at all. Only problem is that it will take a week to get.

Let me know via pm and we can workout details if you want to proceed.
Click to expand...

Thanks Joe. Sent you a PM :)
 
Devg, Is the noise from one amp or both? Once in a while the plates on a transformer have not been sandwiched together properly during the manufacturing process and can buzz. Many transformers also can be polarity sensitive. Inverting the input can sometimes greatly reduce transformer output noise. However, not being familiar with the circuit it is being used in it is best to confer with Colin and to follow his advice.
 
jadedavid said:
Devg, Is the noise from one amp or both? Once in a while the plates on a transformer have not been sandwiched together properly during the manufacturing process and can buzz. Many transformers also can be polarity sensitive. Inverting the input can sometimes greatly reduce transformer output noise. However, not being familiar with the circuit it is being used in it is best to confer with Colin and to follow his advice.
Click to expand...

Fortunately or unfortunately, both the Amps :(
 
Mine showed up about 9 am and was put in place of the Job. Checked it after about six hours of power up and even with my ear to the case it is dead silent.
 
Devg

If you have a cheater plug or two lying around give that a try. Easy enough trouble shooting step and will give you some idea of where the problem my lie. I had a similar situation earlier in the year when I inserted a new tube amp in to a previously dead quiet set-up where nothing else changed. Cheater plug solved the situation until I had time to open the it up and re-route some crossed wiring.
 
Jack said:
Devg

If you have a cheater plug or two lying around give that a try. Easy enough trouble shooting step and will give you some idea of where the problem my lie. I had a similar situation earlier in the year when I inserted a new tube amp in to a previously dead quiet set-up where nothing else changed. Cheater plug solved the situation until I had time to open the it up and re-route some crossed wiring.
Click to expand...

Jack,

Just tried one cheater plug I had in stash. Didn't help :(
 
.... Take one of the amps to an entirely different building and check it there?


Ps Unless there's a polarity issue that might be solved internally and easily.... maybe Colin can answer that?
 
I just checked my Nords with the preamp and dac off and I get a little nasty squirrelly sound from the tweeters. When I get down and listen to the amps the right one has a little buzz but not bad. The left one is a little more pronounced but I'm really close to the amp.

When everything is hooked up and on but no music the left speaker has slight hum in the mid driver and just hiss in the tweeter. Right channel is same but not as much. When I insert a passive preamp the noise from the speakers goes up quite a bit.

So do you guys not only get dead silence from your amps but also from your speakers?
 
MikeCh said:
.... Take one of the amps to an entirely different building and check it there?


Ps Unless there's a polarity issue that might be solved internally and easily.... maybe Colin can answer that?
Click to expand...

No, I am yet to take the Amp out to a different location. I checked the polarity of my outlets using a polarity checker and it seems fine.
 
Tomy, I think we are hearing the same buzz from the Amp. In my case, they are both the same intensity and I could hear if I put my ears closer to the chassis.

Now since others have stated its dead silent and couldn't hear anything when close to it, I am assuming there is something going on either with my power or amp.
 
Devg said:
Tomy, I think we are hearing the same buzz from the Amp. In my case, they are both the same intensity and I could hear if I put my ears closer to the chassis.
Click to expand...

Everything I had read about a Hypex amp was that they are dead silent so when I first fired them up I was a little disappointed there was a slight hum and hiss. When music is playing everything is fine and they sound great. The Hattor passive I ordered is coming next week and I was hoping for a dead silent system. We'll see.

Evrything is plugged into the same outlet by the way. If it's a matter of tightening down a transformer hopefully Colin or somebody can show a picture of what and where...
 
tomy2,

Disconnect your input cables to the Nords and see if the noise goes away or if it changes at all.
 
You must log in or register to reply here.
Back
Top