Hypex Ncore NC502MP - audible hum on one channel?

[jtwrace]

They get a workout daily as this is always on while working in the other room.

 

[marcom22]

It's on all NCxxxMP. They need a clean implementation. The issue was highlighted here when @Amir tested an NC502MP based amplifier.

Sorry BoXem but Amir doesn't found this hum on anyone Ncore, where did you read about it?

 

[mdsimon2]

I have 5 Audiophonics XLR input NC252MPs with no hum (dead silent).

Michael

 

[marcom22]

I'll hope that Audiophonics will replace your Amp because it's not acceptable. And please let me know how this case will end, because i want to replace my amp nc252mp with a new one nc502mp but if this is the assistance from Audiophonics I will change dealer

 

[simbloke]

I don't hear the slightest hum or hiss from my MPA-M250NCs connected to a DAC via RCA. But if it's a ground loop hum then there are so many differences between situations that this might not mean much, sorry.

 

[MoreCowBell]

I'll hope that Audiophonics will replace your Amp because it's not acceptable. And please let me know how this case will end, because i want to replace my amp nc252mp with a new one nc502mp but if this is the assistance from Audiophonics I will change dealer

They offered me a refund because they do not view the product as defective. As indicated above, Audiophonics states that they have tested all of their remaining LPA-S500NC stock and heard the hum in the right channel. So in their view because the noise is heard in all their products then the product is not defective... this does not make sense to me.

 

[boXem | audio]

Sorry BoXem but Amir doesn't found this hum on anyone Ncore, where did you read about it?

 

[restorer-john]

It's less of a hum and more of a low level buzz as the predominant spurs are higher order harmonics of the mains supply frequency.

 

[MoreCowBell]

It's less of a hum and more of a low level buzz as the predominant spurs are higher order harmonics of the mains supply frequency.

Yes, a low level buzz is accurate. I just purchased a p502 from March audio. I am hoping, with March audio’s better implementation, that the noise will be nonexistent. I will provide an update upon receipt.

 

[Chrispy]

They offered me a refund because they do not view the product as defective. As indicated above, Audiophonics states that they have tested all of their remaining LPA-S500NC stock and heard the hum in the right channel. So in their view because the noise is heard in all their products then the product is not defective... this does not make sense to me.

Some logic there....

 

[boXem | audio]

1. I type it's an integration issue.
2. I show the measurement of an amp with integration issue.
3. Readers purchase the amp with integration issue.

 

[MoreCowBell]

1. I type it's an integration issue.
2. I show the measurement of an amp with integration issue.
3. Readers purchase the amp with integration issue.

Before I made the purchase I spoke to Alan March about this measurement and he states that the mains and harmonics pick up were predominantly due to the set up as was later discussed in the p502 test thread. He also believes that the levels are inaudible. He asserts that the problem I had with my previous amp was due to the xlr pin 1 being incorrectly wired.

Despite your claim that my hum/buzz issue is well known across all hypex nxxx modules others members who own various hypex Ncore amps (including members who own the same identical amp that I had issues with and March audio amps) all indicated that their amps are silent and do not present my issue. I will provide an update when I receive the p502 amp.

 

[restorer-john]

Before I made the purchase I spoke to Alan March about this measurement and he states that the mains and harmonics pick up were predominantly due to the set up as was later discussed in the p502 test thread. He also believes that the levels are inaudible. He asserts that the problem I had with my previous amp was due to the xlr pin 1 being incorrectly wired.

Your amplifier may well become extremely well travelled- going from Australia, to Miami US and back to Australia.

 

[abdo123]

Before I made the purchase I spoke to Alan March about this measurement and he states that the mains and harmonics pick up were predominantly due to the set up as was later discussed in the p502 test thread. He also believes that the levels are inaudible. He asserts that the problem I had with my previous amp was due to the xlr pin 1 being incorrectly wired.

Despite your claim that my hum/buzz issue is well known across all hypex nxxx modules others members who own various hypex Ncore amps (including members who own the same identical amp that I had issues with and March audio amps) all indicated that their amps are silent and do not present my issue. I will provide an update when I receive the p502 amp.

If a waiter spit in your soup, would you be okay with it if you couldn't taste the spit?

1. I type it's an integration issue.
2. I show the measurement of an amp with integration issue.
3. Readers purchase the amp with integration issue.

I doubt it's the exact same issue since a 3 dB drop in SINAD will not result in audible hum, do you think that implementation + certain conditions will create the hum?

 

[MoreCowBell]

If a waiter spit in your soup, would you be okay with it if you couldn't taste the spit?

If a bear farts in the woods and no one is there to hear it, does it still smell?

 

[abdo123]

If a bear farts in the woods and no one is there to hear it, does it still smell?

it's your money, there are like 123210252 entities building hypex based amplifiers and you decided to pick the entity that does a subpar job.

it's rude to ask for someone's opinion and then make fun of it.

 

[MoreCowBell]

it's your money, there are like 123210252 entities building hypex based amplifiers and you decided to pick the entity that does a subpar job.

it's rude to ask for someone's opinion and then make fun of it.

Sorry my bear farting in the woods comment was made in jest; I did not intend to offend you.

When I did my research I only found a few companies (outside of the big manufacturers such as NAD) that offered warranties, had decent reviews, at a “reasonable” price for hypex based amps. Which companies do you suggest?

 

[restorer-john]

f a bear farts in the woods and no one is there to hear it, does it still smell?

That's actually rather funny.

I'm visualizing a bear, looking around to make sure nobody is around and then tearing a rotten and gaseous plume, only to see someone watching him and recoiling in horror as the putrid stench wafts over their nostrils as they recoil in olfactory horror.

 

[Matias]

Before I made the purchase I spoke to Alan March about this measurement and he states that the mains and harmonics pick up were predominantly due to the set up as was later discussed in the p502 test thread.

This. Amir had a ground loop in the measurement and Alan proved it in the 3rd page of the thread. It was NOT a bad implementation, but bad measuring in that particular case.

 

[restorer-john]

@MoreCowBell You don't have bears in Miami do you? And do they actually fart?

A bit like drop bears here in Australia...