Help Hypex Ncore Nc400 build

[Mr. Green]

Hi,

I have just completed a build of two stero amps based on 4xncore NC400 modules, and 4x smps600. However, there is sligt issues in paradise

When I power them up 3 of the modules light up all leds, which i pressume is and fault indication.

I have looked through the thread on this forum, and picked out a few potential issues and tired to test if they where the reason.

I have investigated if i have shorted the inputs. The input are connnect as follwows: Blue (+) to 2, White to 3, and shield to 1. A wire is then connected form shield 3 to 4 (case) on XLR, and that is then in turn connected to amp module earth.

I have tried to take a crocodile clip from 4 to confimed earth in socket, to see if that woudl turn on the modules. No such luck. I have tried to connect the 4&3 to earth leg on smps600. No luck. I have tried to connect the 3/4 on the one working to the one not working. No luck.


I am running a little out of options, and hope to get some input to what to try next, and what might cause this.

I have attached a few picks for a little clarigy on what goes on in there, on the one where one module i working.

Best
Mik

 

[e_fortier]

Hi

I’m attaching a pic of the XLR connections with a view from the solder side. Upper left is pin 2 (In+), upper right is pin 1 (Shield) and lower pin is 3 (In-)

On the XLR, do not connect together pin 1 and 3.

Also, the wire from J9.3 must be connected to Gnd.

Hope it helps
Eric

 

[Mr. Green]

Hi Erik,

Thanks for the reply.

I have checke the 1 and 3 are not connected on any of the xlrs. By measuring resistance between 1 and 3. No contact. It is 3 and case (4) that is connected.

Measuing from earth pin in IEC to 3 on xlr i measured below o. 7ohm on All xlrs, The same from case (4) as they are connecte that laves me to believe that nAMPON can feel earth then, and that the amp should enable amplifier. But I suppose this means that the amp (that lights up) detects an error condition.

Hmmmm. Not easy this one.

Best mik

 

[russc]

A process of elimination:
As you have one module working, you can try a non-working module in that same location.
This would prove the module to be working or faulty.
I doubt that incorrect wiring of XLR would cause a fault condition, shorting inputs is a standard test when listening for noise, but you can unplug the XLR from the board and see if that clears the fault.
Likewise, when you have proven from the first step which modules are working, you can test the power supplies by plugging each into a working module.
It may be best to test operation not on your best speakers in case of fault.

 

[spikestabber]

The one that isn't lighting up is your problem, nc400 use the LED's as zener diodes as voltage references, abiet drifty ones with temperature... the nc400's that are lit up are working.

 

[russc]

1 out of 3 not working is 3 times better than 3 out of 4.
Same principle of testing.
Narrow fault to module, power supply or wiring.

 

[spikestabber]

Either PSU is not supplying power or nAMPon is not connected to ground properly.

 

[Mr. Green]

Hi again,

@spikestabber: Thank for clarifying the diode light. That means i have working amp. Which is fantastic. And I agree to you analysis of nAMPON and PSU.

@russc i definatly agree. 3 is better than one i will definatly do some position switching between the to single out possible sources of error. Supply of power, nAMPON, and fault module.

Thank you both for input. Really appriciated.

I will try ang hook the working one up to a set of speakers and see what the fuzz is All about

Best mik

 

[Mr. Green]

Hi found out one of the modules where somehow not working. Have returned it to Hypex which have repaired it with no Reservations, and has been very civil about it and very help full in providing help.

But the modules provide a little to much power for my 110db speakers. Any suggestions for how to best attenuate these modules?

 

[HelmutHolz]

My experience: very nice amps, especially for my Dynaudio Confidence 5. But using them for high efficient fullrange is not usefull, bad sound. Remember, the first watt counts.

 

[spikestabber]

Wasn't that the big thing about certain tripath amps (the TA2024 for example) that made them so popular back in the day? If I remember they had incredible first watt perf for its time, for a D ("T") class it was unheard of. I do recall a lot of people driving very high efficiency full rangers with good success. Though I'd imagine anyone with speakers in that range of efficiency would have a full suite of pure homegrown A class somewheres.