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squeedle

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I've become intrigued by the Hypex NCore amplifiers (particularly NC502MP) and this site is one of the few I've found with meaningful discussion and commentary about the various options available on the market. But it's also left me feeling a bit baffled and concerned about whether the whole thing is a bit of a crapshoot or not. I'll try to itemize and distill what I've gleaned from reading the threads so far, and I'm hoping you guys can help to correct/clarify/confirm/etc. where possible. It's entirely possible I've mis-remembered or misinterpreted some things. Hopefully this can offer some finality and clarity on some of these issues. I've numbered the issues below for quick reference in replies.

1) All NCore Modules MAY Have Audible Hum?
In one thread, a user returned an NCore amp to Audiophonics, who then supposedly confirmed that they tested all their NCore products and they all produced the same audible hum, so it was "totally normal", and "you wouldn't hear it more than 2 feet from the speaker". Meanwhile, other users chimed in that their NCore amps were "dead silent". What is the final verdict on this? Audiophonics doing something wrong (and therefore a vendor to avoid?), or what?

2) OEM NCore > End-User NCore?
Only manufacturers (including all those listed on this page) have access to the super-duper whiz-bang elite-level NCore boards that are desirable. End-users can only buy poopified lesser versions.

3) The Cheapest Pre-Assembled Amps Are Sketchy?
The 3 cheapest common options I could find for pre-assembled amps were from VTV, Buckeye, and Audiophonics.
a) VTV was said to have very sketchy build quality, with improperly-fitting connectors + duct tape, sloppy soldering, and potentially dangerous wiring mistakes. They claim to have addressed the "pin 1 problem", have they addressed the other issues?
b) Deleted.
c)
Audiophonics may have improper wiring and audible hum. They are based in France so return shipping and/or warranty claims would be extra annoying.

4) Proper RCA-to-XLR Cables Are Elusive?
I'm still unclear if the affordable Monoprice RCA-to-XLR cable (p/n 4777) is "good" or "bad" for this purpose. Some threads seem to allege that all commercially available options don't have the right wire-mapping and you have to make your own, which seems ridiculous if true.

5) RCA-to-XLR Cables Preferable to RCA Only?
Some amps have RCA and XLR inputs. Others have only one or the other. Some threads seem to allege that using RCA-to-XLR cables offers better sound quality compared to just using RCA cables and RCA inputs.
a) First of all, is this actually true, and if so why? Presumably an amp with RCA inputs has those inputs properly grounded, same as an RCA-to-XLR would be?
b) Secondly, does this mean that the very presence of RCA jacks on an amp means the sound quality will be degraded, even if only using the XLR inputs? For example, Audiophonics amps include both RCA and XLR inputs. Is that going to be worse than a similar amp with only XLR inputs?

6) Trigger Or No Trigger?
Some amps offer a 12V trigger. This seems like a good option but raises several potential issues:
a) Does the trigger add any noise or potential issues? I seem to recall some posts about users having to disable that feature as it was causing problems. These amps should have minimal power draw when not being used, yes? How important is the trigger?
b) Which manufacturers have soft-on/soft-off to avoid popping when powering their amps on or off? Is this a feature built-in to NCore boards or is it something manufacturers add?

7) March Audio FTW?
The March Audio offerings don't seem to offer RCA inputs or 12V triggers as options. And based on their sales rep's knowledgeable, coherent, and articulate responses in several posts, they seem to know what they are doing compared to other manufacturers (including some that are outside my price range like Nord--who also seems to have the "pin 1 problem"--and Apollon). Is March Audio basically the safest bet here all around? Their price is higher than Audiophonics but below Nord and Apollon; and they are in Australia which = expensive shipping to USA and also potentially annoying warranty scenarios. But they seem to be the only (?) truly safe option right now. Is this correct, or have there been any issues with their NCore amps reported?

Is there anything else I missed? I would love to identify a top pick or two among these offerings for myself and perhaps that will be helpful to others in the same situation as well. Thanks for your contributions!
 
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Chromatischism

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I'll take a stab at a couple of these...

2) OEM NCore > End-User NCore?
Only manufacturers (including all those listed on this page) have access to the super-duper whiz-bang elite-level NCore boards that are desirable. End-users can only buy poopified lesser versions.
Sounds like bollocks to me.

c) Audiophonics may have improper wiring and audible hum. They are based in France so return shipping and/or warranty claims would be extra annoying.
Definitely not the case with mine. I have also not seen such complaints from others here.

6) Trigger Or No Trigger?
Some amps offer a 12V trigger. This seems like a good option but raises several potential issues:
a) Does the trigger add any noise or potential issues? I seem to recall some posts about users having to disable that feature as it was causing problems. These amps should have minimal power draw when not being used, yes? How important is the trigger?
b) Which manufacturers have soft-on/soft-off to avoid popping when powering their amps on or off? Is this a feature built-in to NCore boards or is it something manufacturers add?
Trigger works like a treat and is an important feature for me. Clicks on and off with the AVR. You don't want to have to walk up to power on gear that didn't turn on with your remote. No popping – the Audiophonics amp has a board that helps with soft on/off. You can see it if you look at the pictures.
 

Koeitje

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2) OEM NCore > End-User NCore?
Only manufacturers (including all those listed on this page) have access to the super-duper whiz-bang elite-level NCore boards that are desirable. End-users can only buy poopified lesser versions.
The NC400 DIY option is technically the best performing one. Its easy to make, because its pretty much plug and play.
 

Chromatischism

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You sure?
At least I assumed that's what it was. It differs from the reference design. All I know is mine never pops, so it's not a problem!

Hypex NC252MP:

NC252MP.png


Audiophonics:

audiophonics-mpa-s250nc-rca-class-d-stereo-amplifier-ncore-2x250w-4-ohm.jpg


Looks like it's connected to the RCA inputs and the 12v trigger
 

abdo123

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b) Buckeye was said to be made by a college student in his spare time and potentially also have dangerous wiring and other quality control issues.


what's up with people thinking assembling a hypex amp requires a PhD or something? someone doing an engineering bachelor with anything remotely close to electric engineering, or even signal processing would be able to do it with their eyes closed.

these people learn how to design the amplifier they're assembling, not just assemble it.
 

simbloke

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You don't say where you are, which can be important as some products are easier to obtain in some areas.

I have the Audiophonics 250w monos, that I always forget the model number of! I don't hear any noise from their cases or at the tweeter. Nor any clicks when I turn them on and off. However I don't think they have an extra circuit for this.

As far as I know the triggers are connected to one side of an opto-isolator.

You should also look at the @boXem | audio stuff, I would if I were buying now.
 

boXem | audio

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It may be the relay that achieves that. There are 2 clicks over a couple of seconds before the amp is fully functional.
That is strange, the only visible relay is the one from the power supply that cannot be driven from outside.
Soft start is ensured by the module, not with relays but simply with proper output FETs energizing sequence.
 

oupee

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@squeedle
I recently bought an Audiophonics nc250 monoblock. No crackling or humming. From what I've read here, one channel in the stereo version hums. If you buy monoblocks, it does not apply to you. The rear panel has a cinch / xlr switch. Switching to cinch combines negative and ground. It works without problems.
I don't like heights. For example, Daft Punk - Within 0: 40-1: 40 lacks "glitter, shine, ringing", I don't know how to describe it in English. In addition, the heights sound the same everywhere. As if there was one musical instrument for treble in the world. But I don't want to deal with that here, because it would start a war here. Try to arrange a loan somewhere.
 
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oupee

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At least I assumed that's what it was. It differs from the reference design. All I know is mine never pops, so it's not a problem!

Hypex NC252MP:

View attachment 150357

Audiophonics:

View attachment 150359

Looks like it's connected to the RCA inputs and the 12v trigger
If you mean the board to which the inputs, the trigger are connected ... then it's just a reduction. It is thus easier and more practical to connect the inputs, trigger, button and led there than to plug it all into one long connector.
 

Qbd

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There are a lot of OEM’s, but I’d also add @KJF audio to the list. Really no-nonsense operation (e.g. no waxing philosophical about custom input buffers/op-amps etc.), and seems to use all the features of the hypex boards like clipping indicator, temperature control etc., though I assume some of the others do this as well?

From what I recall the only critical commentary about the KJF MA-01 reviewed here was purely theoretical or irrelevant for consumers. It has also passed a bunch of third-party compliance testing according to the manufacturer.
 

Chromatischism

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That is strange, the only visible relay is the one from the power supply that cannot be driven from outside.
Soft start is ensured by the module, not with relays but simply with proper output FETs energizing sequence.
I need to retract that statement. It is in fact the Denon doing the other click. Waay past my bedtime :rolleyes:

At any rate, the OP should be reassured it is smooth, but I can't guarantee what happens with high efficiency speakers.
 

oupee

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Make sure your DAC/Pre or AVR can drive it:

View attachment 150366
Exactly. On my B class amplifier which has "only" 100W / 4ohm I have to remove 4db on the preamplifier to have the same volume as nCore. nCore has low input sensitivity. For laymen, it can seem less louder than a weaker amplifier with better input sensitivity.
 

McFly

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1) All NCore Modules MAY Have Audible Hum?
Would depend on your woofer/system sensitivity. A big pro/diy 95-100db 12-15" woofer, you may get some hum. Most consumer grade hifi stuff bandied about here? I really doubt it.

(Context: I currently use a 6 channel active system, so no passive crossover parts, with a NC502 running lows, NC252 running mids and NC122 running highs. All drivers connected directly to purifi module outputs)

For example, with my purifi woofers, I get no hum, even with my ear up to the woofer. With the satori MW19TX-4, which is about 6db more sensitive, I get a faint hum with my ear up to the woofer. Nothing audible in room though.

My biggest problem by far as the turn off pop I get on the tweeters connected to the NC122MP. Protection capacitors helped a little.

2) OEM NCore > End-User NCore?

Forget it. No-one would bother with this.

3) The Cheapest Pre-Assembled Amps Are Sketchy?

You get what you pay for. If your clued up enough, and you should be after reading this site some, you can buy the cheapest and check it over yourself, make necessary tweaks and live happy ever after. Problem these days seems to be everyone just buys stuff and returns it within a week because it didnt give them the audiophile high they thought they were gonna get. Man I feel for some manufacturers.

4) Proper RCA-to-XLR Cables Are Elusive?

Probably going to be cheaper to buy a dac or pre with xlr out.

5) RCA-to-XLR Cables Preferable to RCA Only?

As above..

6) Trigger Or No Trigger?

Triggers a nice thing to have if you have the means to trigger it.

7) March Audio FTW?

Ive got both march and buckeye. If you're not looking at the casework, go buckeye.
 

deafenears

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The March Audio offerings don't seem to offer RCA inputs or 12V triggers as options.
I thought their latest offerings included 12V triggers?

Also, it's easy enough to have and RCA to XLR adapter or cables for inputs into the amp itself.
 
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