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Apollon NCx500ST Stereo Amplifier Review

Rate this amplifier:

  • 1. Poor (headless panther)

    Votes: 3 0.7%
  • 2. Not terrible (postman panther)

    Votes: 4 1.0%
  • 3. Fine (happy panther)

    Votes: 30 7.3%
  • 4. Great (golfing panther)

    Votes: 375 91.0%

  • Total voters
    412

formdissolve

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Funny, my old NAD 2200's consume very little power, they 3 & 2 APT/Holman Preamps have been left on for years at a time.
Going on 7 months of work away from the home (shutting the stereo down & disconnecting it all from the mains shows very little effect on the power bill (if any).
The water bill sees a substantial drop, though. Are the amps drinking water when I'm home but not looking at them?
Energy costs in Europe are much higher than most of the USA, so people over there care more about idle watts.
 

EJ3

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Energy costs in Europe are much higher than most of the USA, so people over there care more about idle watts.
I am including my time (17 years) in Saipan where energy costs are even much higher than Europe. (Also, I was born in Salzburg, Austria & have a condo there).
As an example, in 2003, my 2 bedroom, 1 bathroom apartment rent was $550 USD a month & my electric bill was $650-660 USD a month (there was no water bill at the time, there was enough salt in the city water to make most shampoo's non-functional [and you made sure not to swallow any when you brushed your teeth]).
The electric bill did not seem to fluctuate much (even though [in my village] the power company stupidly instituted a blackout from noon to 1400 every day, which just made the air conditioners run harder and use more power to try to cool the apartment down after the blackout).
The temps:
Coldest MonthFebruary (26.22ºC / 79.2ºF)
Warmest monthSeptember (29.34ºC / 84.81ºF)
Humidity77.34%
So, basically hot & humid all the time. Being on the top floor of a 3 story concrete building with a roof painted black, did not help.
But my power bill was helped for 2 hours every day because the 1st floor was a bank. The Bank had an uninterruptable power supply for the whole building, which would come on as soon as the power company blacked out, you could hear a slight tone change in the AC system. And, by the magic of a building wide uninterruptable power supply, our power was free for 2 hours a day.
The best thing is that you only need one wardrobe there, the next is that you never have to worry about snow or freezing to death.
 

Ajax

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I am including my time (17 years) in Saipan where energy costs are even much higher than Europe. (Also, I was born in Salzburg, Austria & have a condo there).
As an example, in 2003, my 2 bedroom, 1 bathroom apartment rent was $550 USD a month & my electric bill was $650-660 USD a month (there was no water bill at the time, there was enough salt in the city water to make most shampoo's non-functional [and you made sure not to swallow any when you brushed your teeth]).
The electric bill did not seem to fluctuate much (even though [in my village] the power company stupidly instituted a blackout from noon to 1400 every day, which just made the air conditioners run harder and use more power to try to cool the apartment down after the blackout).
The temps:
Coldest MonthFebruary (26.22ºC / 79.2ºF)
Warmest monthSeptember (29.34ºC / 84.81ºF)
Humidity77.34%
So, basically hot & humid all the time. Being on the top floor of a 3 story concrete building with a roof painted black, did not help.
But my power bill was helped for 2 hours every day because the 1st floor was a bank. The Bank had an uninterruptable power supply for the whole building, which would come on as soon as the power company blacked out, you could hear a slight tone change in the AC system. And, by the magic of a building wide uninterruptable power supply, our power was free for 2 hours a day.
The best thing is that you only need one wardrobe there, the next is that you never have to worry about snow or freezing to death.
That's an "out there" place you call home. Why is the electricity cost so high, how is it generated.

In Australia today an electrical bill for a 2 bedroom apartment is around $US100 per month against a rental of around 20 times that = US$2,000 per month.

This is very rough and will vary a lot between cities and suburbs and will change drastically upwards as renewables replace coal.
 

YSDR

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There's so much misinformation regarding the "efficiency" of these things.
The correct information is available to everyone, although the NCx500 datasheet don't contain the efficiency chart, the closest thing to it is the NC500, here it is:
NC500_heat_dissipation.jpg

If also we want to consider in with the power supply (because the Appollon NCx500ST have one), then here is the NC502MP as a reference:
NC502MP_heat_dissipation.jpg
 
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Haskil

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I am including my time (17 years) in Saipan where energy costs are even much higher than Europe. (Also, I was born in Salzburg, Austria & have a condo there).
As an example, in 2003, my 2 bedroom, 1 bathroom apartment rent was $550 USD a month & my electric bill was $650-660 USD a month (there was no water bill at the time, there was enough salt in the city water to make most shampoo's non-functional [and you made sure not to swallow any when you brushed your teeth]).
The electric bill did not seem to fluctuate much (even though [in my village] the power company stupidly instituted a blackout from noon to 1400 every day, which just made the air conditioners run harder and use more power to try to cool the apartment down after the blackout).
The temps:
Coldest MonthFebruary (26.22ºC / 79.2ºF)
Warmest monthSeptember (29.34ºC / 84.81ºF)
Humidity77.34%
So, basically hot & humid all the time. Being on the top floor of a 3 story concrete building with a roof painted black, did not help.
But my power bill was helped for 2 hours every day because the 1st floor was a bank. The Bank had an uninterruptable power supply for the whole building, which would come on as soon as the power company blacked out, you could hear a slight tone change in the AC system. And, by the magic of a building wide uninterruptable power supply, our power was free for 2 hours a day.
The best thing is that you only need one wardrobe there, the next is that you never have to worry about snow or freezing to death.
My house, 155 m2, 3 m ceiling, three floors, heated in winter to 19 degrees Celsius, except the bedrooms at 16 degrees Celsius, everything is electric: 320 euros per month, or roughly the same thing in USD.. But I live in France where gasoline is very expensive, but where electric current, although expensive, is much, much cheaper than in Great Britain or Germany...
 

Ajax

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My house, 155 m2, 3 m ceiling, three floors, heated in winter to 19 degrees Celsius, except the bedrooms at 16 degrees Celsius, everything is electric: 320 euros per month, or roughly the same thing in USD.. But I live in France where gasoline is very expensive, but where electric current, although expensive, is much, much cheaper than in Great Britain or Germany...
I assume the less expensive electricity is because France's supply is 70% nuclear .... a lesson for those countries help bent on replacomg coal wth renewables.
 

Julf

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I assume the less expensive electricity is because France's supply is 70% nuclear .... a lesson for those countries help bent on replacomg coal wth renewables.
Indeed. OK, countries with lots of wind, hydroelectric power or sun aren't doing too badly, but the ones who wound down their nuclear plants can only blame themselves.
 

Ecaroh

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I bought one of these amps after reading this review. Have been using it to drive a pair of 4 ohm speakers lately. The gain is on the highest setting, no specific reason for that. It runs pretty hot, like a class A amp, even at listening levels in the 70-80 dB range. Twice lately I've switched it off to roll a different tube into the Musical Paradise MP-701 MK3 preamp. Both times heard a pretty loud pop from the speakers when turning off the Apollon amp. Both times it didn't come back on after the preamp tube change. Seems to be a thermal protection circuit because after it cools down the amp will power back on.
Please post if you hear something from Apollon about these issues, particularly the heat; maybe that’s to do with your gain setting?
 

EJ3

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That's an "out there" place you call home. Why is the electricity cost so high, how is it generated.

In Australia today an electrical bill for a 2 bedroom apartment is around $US100 per month against a rental of around 20 times that = US$2,000 per month.

This is very rough and will vary a lot between cities and suburbs and will change drastically upwards as renewables replace coal.
The island runs on diesel generators.
The few wind mill machines that have been put up did not seem to like the 180 MPH sustained & 223 MPH gusts that we had during

Typhoon Yutu.​

Lazy loaded image

An aerial photo showing the southern end of Saipan almost completely destroyed by Super Typhoon Yutu November 4, 2018 in Saipan, Commonwealth of the Northern Mariana Islands. Photo credit: © James May/ZUMA Press ZUMAPRESS.COM

I do not currently live there (I live on the Island that I grew up on, James Island, a barrier island just off of the coast of Charleston, SC USA).
Here, my wife & I are helping my quite active 90 year old mother for however many years that we have left with her around.
Then we will move back to some island in the Western Pacific, if mot Saipan, one close to it.
 

EJ3

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That's an "out there" place you call home. Why is the electricity cost so high, how is it generated.

In Australia today an electrical bill for a 2 bedroom apartment is around $US100 per month against a rental of around 20 times that = US$2,000 per month.

This is very rough and will vary a lot between cities and suburbs and will change drastically upwards as renewables replace coal.
I rented in Freemantle a car & an apartment for a month (Dec, 2004, I think). It was rather nice there. I found driving on the opposite side of the rode than we do a bit trying initially but was fine with it after a day or 2.
 

Haskil

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I assume the less expensive electricity is because France's supply is 70% nuclear .... a lesson for those countries help bent on replacomg coal wth renewables.
Yes ! Vive De Gaulle ! For two historical reasons: in the past, it was simple: the State had a monopoly on production and distribution to electricity customers: the State imposed prices. And they were very content. Europe which has become liberal has imposed on the French State competition between electricity suppliers which has obviously in no way lowered prices for consumers, but has impoverished the public electricity producer forced to sell electricity cheaper. that it produces to these resale companies... And under pressure from Germany the price of electricity was indexed to that of gas... The State in France decided to create a tariff shield which protected the French from colossal increases in electricity when Russian gas became rare... But that will only last for a while...
As a result, electricity will increase in France because it is necessary to finance the nuclear program fortunately relaunched by the State but the historic electricity producer has seen its margins decrease greatly due to the obligation imposed on it to sell electricity to companies which resell it to people... the same price very often as that which we pay to the historical distributor... Europe is excellent in many areas but not in that of energy ....
 

gwing

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Indeed. OK, countries with lots of wind, hydroelectric power or sun aren't doing too badly, but the ones who wound down their nuclear plants can only blame themselves.
and
Ajax said:
I assume the less expensive electricity is because France's supply is 70% nuclear .... a lesson for those countries help bent on replacomg coal wth renewables.

Sort of the opposite way around on costs though . Here in the UK we did wind down our nuclear program, we aren't as a country against nuclear and have been trying to replace our old nuclear reactors but (unfortunately or fortunately depending on your point of view) nuclear is actually *a lot* more expensive than returnables these days. It is a misconception that nuclear is cheap, it's actually the most expensive form of energy available to us but we'll still need some because of the stability advantages it brings.
 

JeremyFife

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Loving the new AaEER forum (Audio and Energy Economics Review) ;)

I do agree that using our Planet's resources sensibly is something we should strive for, and that wasting energy is a real problem. I also think we should celebrate and support equipment that is efficient as well as being good for audio - we should recognise that as good design.

Perhaps it's also time to get back on thread?

Peace and music :)
 

bmwr75

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Please post if you hear something from Apollon about these issues, particularly the heat; maybe that’s to do with your gain setting?
I did email Tibor at Apollon. However a Google search reveals these Hypex amp modules run very warm.
 

NTK

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Quick calculations:

The idle heat loss for a SMPS1200A700 is 9 W.
The idle heat loss per NCx500 is 5.3 W (typical).
Total idle loss = 19.6 W.

Apollon amplifier case dimensions are: 0.3 m (d) × 0.25 m (w) × 0.069 m (h)
Excluding the bottom, total surface area for heat loss ≈ 0.3×0.25 + 2×0.3×0.069 + 2×0.25×0.069 = 0.1509 m²

From the Simon Fraser University natural convection heat transfer lecture notes:
Natural convection.png


The values of the Prandtl number and physical properties of air are obtained from below:

Calculations:
Natural convection calculations.png


The calculated case temperature is about 50 deg C, which, IMHO, is excessive. There is little reason for it not to be substantially lower than the permitted limit.
Reference ASTM C1055 "Standard Guide for Heated System Surface Conditions that Produce Contact Burn Injuries".

blog5-table2.png
 

Sokel

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NCx500's datasheet is one of the few that doesn't include a power efficiency vs output power and dissipated power vs output power charts.
That's odd.

The only thing it says is 93% efficiency at full power which is meaningless.
 

wizardofoz

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My Apollon 8350 runs hot too even at minimal volumes so I ripen some 12mm x 120mm 12v fans at around 8v to keep some air being pulled through the case
 

Sokel

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My Apollon 8350 runs hot too even at minimal volumes so I ripen some 12mm x 120mm 12v fans at around 8v to keep some air being pulled through the case
You have around 68 W* total idle loss according to the specs,that's on the hot side.
It's not the worst idea to use active cooling but you have to take care of the fine dust from time to time.

* that's not definitive as the NC502MP datasheet reports separate idle losses for the PSU and amp sections,so take that as the minimum.

idle.PNG amp.PNG

Edit:Also the mains IEC socket in the photos looks like a 10A one,for an amp with such spec'd power (500 W x 8 channels) it would need either 2 separate 10A ones or a 16A (barely adequate) for 240V mains in the very extreme case one would drive it to it's limits.
 
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