BUCKEYEAMPS Hypex NCx500 Amplifier 2channel Review

[Rick Sykora]

The minimal difference for different line voltages was already discussed earlier in this thread and the Hypex data shared in this post:

BUCKEYEAMPS Hypex NCx500 Amplifier 2channel Review

OK. It's really simple. Continuous power is just that. No pissing around. How much continuous power can your amplifier deliver at its rated distortion, bandwidth and at what load impedance? Not for 10 seconds. Not for 30 seconds. Not for for 1 minute before exploding. 5 minutes is the latest...

www.audiosciencereview.com

For more than 2 channels, there might be a case for higher line voltage. For this amp, it is 10-20 watts. Hardly a huge boost that would justify the added house wiring. Also, the Hypex supply is not auto-switching and needs jumper changed to switch line voltages.

 

[Sal1950]

I don't understand the big bru-ha-ha going on here.
John Atkinson at Stereophile also tests components designed for US 115v mains, that's the SOP.
He also routinely discusses the issues he runs into when power testing and that many (most?) high power amps are not
making spec into very low impedance's due to the mains voltage starting to droop from the large current draw.
That's just life in the big city.
I'm sure most Pro High End audio and HT installers take these things into account and make the necessary adjustments
for AC power needs.
Personally I have 2 separate dedicated 115v 20a lines feeding my 5.2.4 music system.

 

[Buckeye Amps]

Look at Buckeye's 8 channel NC502MP. Uses 2 inlets for double amps still in 110V, no 240V option.

The NCxxxMP are 120/240V compatible. No option/jumper needed.

 

[ClaudeJ1]

I have only rarely seen dBW (note "B" and "W" are capitalized since they stand for individuals' names) spec'd for audio amplifiers, and those were pro amps (like PA amps for 80 V systems) years ago. A simple linear number is easier for people to understand since IME most folk have forgotten the few times they were exposed to logarithms in school. And as @restorer-john noted dBW is meaningless without specifying the load (speaker) impedance since most audio amps look like voltage sources and not power sources. IME dBW as a unit is used more, and makes more sense, for controlled-impedance environments like RF systems.

Watts are always specified at 8, 4, and 2 ohms. dBWatts make more sense than watts but marketing types won't allow it because the numeric RANGE that results in just Watts per channel, etc. Example: 10,000 watt pro amps at 4 ohms are only 40 db watts. Not a very impressive number, that second one specifying the same amplifier is it?
Fact is, it makes more sense regardless of contrary "opinions" from certain individuals. Especially those who have opinions with no data to back it up. This my only point because of all the people slamming a great amp at a low price just because if was a few watts short of it's spec and had a power supply issure which they are fixing. I just think some people are not realistic with their opinions and comments, and mostly don't appreciate a great product that costs so little vs. the ones that are priced like sports cars in the audio world. That's all. Sorry about the missed spelling of db Watts, DBwatts, or whatever the correct one is.

 

[restorer-john]

Watts are always specified at 8, 4, and 2 ohms. dBWatts make more sense than watts but marketing types won't allow it because the numeric RANGE that results in just Watts per channel, etc. Example: 10,000 watt pro amps at 4 ohms are only 40 db watts. Not a very impressive number, that second one specifying the same amplifier is it?
Fact is, it makes more sense regardless of contrary "opinions" from certain individuals. Especially those who have opinions with no data to back it up. This my only point because of all the people slamming a great amp at a low price just because if was a few watts short of it's spec and had a power supply issure which they are fixing. I just think some people are not realistic with their opinions and comments, and mostly don't appreciate a great product that costs so little vs. the ones that are priced like sports cars in the audio world. That's all. Sorry about the missed spelling of db Watts, DBwatts, or whatever the correct one is.

 

[DonH56]

You don't want to try again? I picked up a stomach bug and this is just making it worse...

Watts are always specified at 8, 4, and 2 ohms. dBWatts make more sense than watts but marketing types won't allow it because the numeric RANGE that results in just Watts per channel, etc. Example: 10,000 watt pro amps at 4 ohms are only 40 db watts. Not a very impressive number, that second one specifying the same amplifier is it?
Fact is, it makes more sense regardless of contrary "opinions" from certain individuals. Especially those who have opinions with no data to back it up. This my only point because of all the people slamming a great amp at a low price just because if was a few watts short of it's spec and had a power supply issure which they are fixing. I just think some people are not realistic with their opinions and comments, and mostly don't appreciate a great product that costs so little vs. the ones that are priced like sports cars in the audio world. That's all. Sorry about the missed spelling of db Watts, DBwatts, or whatever the correct one is.

10 kW is 40 dBW no matter the load impedance. That is one problem with using dBW instead of just W; impedance is masked. If the amp "doubled down" then you would have 40 dBW at 4 ohms and 37 dBW (5 kW) at 8 ohms, showing the 3 dB difference, which is what I think you are arguing for? If people were properly educated about W, dBW, impedance, Ohm's Law, and such then they would know that 10,000 W and 40 dBW represent the same power and understand why a voltage-limited amp would reduce power by 3 dBW when impedance is doubled. But then they'd all be engineers.

I have not been following the debate; I am guessing you feel using dBW would better represent the (small) difference between say a 105 W/ch and 125 W/ch amplifier? True enough, but we'd have to do a lot of educating. Most folk follow linear math like W, less so logarithms for dBW. Here we'd note 3 dB is a very minor increase in loudness for double the power and going from 105 W to 125 W is only 0.76 dB, barely noticeable. Ultimately you have to relate to something like loudness (phons) or SPL that people understand (sort-of).

Missing spec is, well, missing spec. I thought Dylan had already corrected that in his literature/website but haven't looked. I know he is working with another power supply manufacturer to achieve full performance from the modules.

Not sure why you think I have no data to back my opinions but do not really care at this point. If you want references, check out the IEEE, IEE, or other Standards for the definition and usage of the dBW unit.

 

[Mario Soldier]

That is fine for someone who really needs to squeeze that last 10% (or less?) more out of those amps.

For a lot of people, if they want that little bit more, they might just buy a bigger amp. I am one of those people, so I would get a 500 W amp if I think I need 100 W or less. I really don't care if using 120 V means my 500 W amp plugged into to a 230 V outlet means the amp is only rated 400 W. So the NCx500 measured using the 120 V US standard is great. Those intend to plug the amp into 230 V already know they will get more than the measurements may indicate.

With the Jeff Rowland 535 1050 Watt(230 Volt) bridged vs 700 Watt (120 Volt) this is more than 10% it is a lot(more than 30%) .... and a lot more if you have problems with clipping.But thats just off topic in this thread.And i dont know how much is the expense to run amps in north america with 240 Volt.I thought there are no costs.

And there is a point there are no more powerful amps (you need possible for big subs)

For the Hypex 1200 SMPS you are right it does not really matter running it with 120 or 240 Volt i think but at the begining i was not sure.
But now i read the data sheed of the 1200 SMPS......

 

[Mario Soldier]

Not everyone needs the extra power. And it's not always cost-effective to get a new 240V circuit wired into one's listening room compared to just spending a bit more on an amp with more power.

Sorry i thought , switching some cables is a lot less expensive than buying a new amp.
I dont know the expense to go with 240 Volt in NA.

 

[Mario Soldier]

I don't understand the big bru-ha-ha going on here.
John Atkinson at Stereophile also tests components designed for US 115v mains, that's the SOP.
He also routinely discusses the issues he runs into when power testing and that many (most?) high power amps are not
making spec into very low impedance's due to the mains voltage starting to droop from the large current draw.
That's just life in the big city.
I'm sure most Pro High End audio and HT installers take these things into account and make the necessary adjustments
for AC power needs.
Personally I have 2 separate dedicated 115v 20a lines feeding my 5.2.4 music system.

Problem is dedicated lines can make hum with hifi equipment (i had problems with the old preamp with only rca) and solved them using only one line for preamp and all poweramps.

 

[Chrispy]

Sorry i thought , switching some cables is a lot less expensive than buying a new amp.
I dont know the expense to go with 240 Volt in NA.

No, it's the in-wall wiring that needs to be addressed in most cases, so installing more sufficient wiring to the appropriate panel entails generally tearing up/patching/re-painting....for a slight advantage.

 

[Sal1950]

Problem is dedicated lines can make hum with hifi equipment (i had problems with the old preamp with only rca) and solved them using only one line for preamp and all poweramps.

There are always ways to solve ground loops.

 

[Chrispy]

There are always ways to solve ground loops.

And sometimes takes a bit of effort to determine what they are before you can solve them?

 

[Mario Soldier]

There are always ways to solve ground loops.

The best way was using XLR . Or building real class2 devices without earth....

The easiest way for me was using only one power socket.....


But everyone who has problems with hum solved it on its own way.

 

[Rick Sykora]

You don't want to try again? I picked up a stomach bug and this is just making it worse...

Hope you feel better soon!

Am still baffled how the recent posts to this thread seem worried that our measly 120V service (1800 watts on 15A circuit) does not have enough power for an amp that (at worst very momentarily) pulls 1200 watts. Am very confident my wife’s hair dryer is more likely to draw more power than this amp.

 

[peng]

This is not "additional" it is necessary. The amplifier modules should not be allowed to overload the PSU. The protection should kick in after 9s and reset after a sufficient time.

I understand your point, but unfortunately, that depends, protective schemes are in general, not fool proof. For example:
a) For short cct protection, a protective scheme may trip very quickly, almost instantaneously.
b) For overcurrent (major overload but not short cct conditions), the scheme may trip on time, that follows an inverse time/current characteristics.

Regardless, in either case it is not a guarantee that the protective scheme can prevent failures 100% of the time. For example, argument sake, if a) is a dead shot and the input power supply source has very high fault level, even if the protection scheme so very fast, close to truly instantaneous, damage could still occur before the circuit trips. Similarly, if b) is an overcurrent event that don't quite follow the designed time/overcurrent characteristics, damage could also occur prior to the circuit interrupt (trip).

In power system protection, protection engineers have to carefully analyze all sorts of fault conditions, calculate the fault levels at each points carefully and then design the schemes that have the best chance to minimize interruptions to customers while still protecting the equipment such as generators, transformers, capacitors, inductors, overheat lines, cables etc., but despite their best effort, customers would still get their shares of power interruptions and sometimes even prolonged interruptions because some equipment would still get damaged.

 

[peng]

There are 28 pages of discussion so far, may be a little recap is necessary before then @thin bLue retest the unit with the replacement power supply.

I would like to remind him of the following, since I must have missed a few important points so hopefully others would help:

As @restorer-john mentioned, if tested the same way, damage may occur again, so it would be better for thin Blue himself to read the Hypex data sheets for the power amplifier module as well as the SMPS.

https://www.hypex.nl/media/8c/22/86/1646037796/SMPS1200Axx0_10xx.pdf

https://www.hypex.nl/media/74/2a/5b/1678365773/NCx500%20-%20Datasheet%20R0.pdf

The relevant part of the data sheets have been posted by members many times, but to summarize:

a) The data sheet for the SMPS stated: Power output 1200 W, 4 ohms, 230 V 50 Hz, duration: 10 seconds, heat sink temperature 95 C.
b) It also stated Continuous output power: 325 W under the same conditions, but did not say continuous indefinitely
c) The data sheet for the NCx500 module stated: Peak power output 700 W, 1 kHz, 1% THD, Continuous output not specified but it has:

- thin Blue mentioned his sweep covers 150 points, I am not sure how it would relate to the 10 s, 95 C heat sink temperature, but it does seem based on the data sheet information, he could take some precautions to avoid damage.

- It seems the SMPS data sheet has more details on its limits than the amp module, but the fact that it is only 1200 W, ie 600 W per channel if both driven simultaneously rated for 10s, it is the part that is more prone to damage in the kind of tests thin Blue did the first time.

- Although the data sheet mentioned 325 W continuous, it may be reasonable to assume it means continuous indefinitely but it is still just a reasonable assumption, but it would mean for test duration, thin Blue would have no need to subject the dut to 325 W (both channel driven) for longer than a few minutes anyway. As I assume he is not planning on conducting a real continuous indefinitely power output test.

The datasheet for the SMPS does not say much about protection, other than it does say:

The fact is, it does suggest adequate cooling measures, and without more detailed description of the protection scheme, I don't think thin Blue should rely on "protection" to save the day on the upcoming retest. The protection scheme may be okay for real world use for music and movies contents, but for testing with continuous sinewave (here "continuous" simply means a continuous wave, as opposed to test pulses), I highly doubt it is anywhere near to being fool proof against potential damage.

The datasheet for the NCx500 amp modules has more to say about "protection":

If reasonable precautions are taken, and it doesn't get "fried" this time, we still cannot conclude if the first SMPS had a defect in it; and may have to wait for Hypex to do their own autopsy, if they would bother at all, but hopefully buckeye amp can convince them to do it for ASR members, and potential customers sake.

 

[DS23MAN]

Hope you feel better soon!

Am still baffled how the recent posts to this thread seem worried that our measly 120V (1800 watts on 15A circuit) does not have enough power for an amp that (at worst very momentarily) pulls 1200 watts. Am very confident my wife’s hair dryer is more likely to pull more power than this amp.

This beast can run on 120V, but even on 240 your outlet will be struggling:

Hypex SMPS3kA400 Switch Mode Power Supply

The SMPS3kA400 is a 3000W high efficiency switch mode power supply designed to be used in combination with our range of UcD and NCORE® amplifier modules

www.hypex.nl

 

[Rottmannash]

Sorry i thought , switching some cables is a lot less expensive than buying a new amp.
I dont know the expense to go with 240 Volt in NA.

Let's just say licensed electricians in the US are almost on par with doctors in pay rate/hour.

 

[thin bLue]

I'm in progress with Multimeter, Ch1 was nothing different with all gain as before, Ch2 Med shows increasing DC offset. test time starts to go loooooong.
I need to see stabilising after turn off too, so at least +20min will be spent after dc offset stops increasing. So please wait a bit(?) more for the full test to be uploaded.


Under 40 mV offset under 4 Ohms would be fine for most of speakers, so 4 - 6 mV does not even matters at all. But we wanna know where does it go.

Ignorance is Bliss. But It's very difficult to try to ignore what you already be aware of. And to stop ignoring takes massive amount of time and money, but once you step in, you can never stop on your own. Further more noticing that you don't know can add a lot of psychological pain. But that is equally unstoppable too. Because that is the self-destructive instinct of human beings who are designed to know. And everyone's comments also teach me a lot that I don't know yet.

I am sorry for not being able to reply to each one individually. Thank you vary much!

 

[DS23MAN]

It will stabilise at just above 5 mV.....