[farquad]

That's what I was wondering when I posted

Not everyone can afford a nice Fluke meter, but with all due respect I can't really imagine attempting even a basic modular DIY build without some sort of meter to test for voltages and continuity/shorts which can be readily be measured with a very basic $10 - $20 multimeter.

Steve

Exactly as Steve says. A multimeter is a must have.

[Julf]

its not money, its that I wouldn know what to do with it.

The problem is that the nc400 is meant for DIY people - and that assumes a basic understanding of electronics and the standard tools of the trade (solder iron, multimeter etc,).

I started this project thinking it would all be plug and play like a pc build!

And it is - on the Hypex end of things. If you get and use solder connectors, they will have to be soldered. Everything on the Hypex modules is plug and play.

What is the loudspeaker connection issue and how do I resolve it?

Have a look at figure 2 on page 13 of the nc400 data sheet, and make sure your wiring is the same. Then make sure that nAMPON is connected to ground (the shielding of the shielded cable), and that the speaker outputs are isolated from your enclosure.

[Speedskater]

To much cutting and pasting try:

NC400 datasheet

http://www.hypex.nl/component/weblinks/weblink/24-datasheets/28-nc400-datasheet.html

[zenpmd]

We have sound! It sounds so good I could cry.

My setup is with the Benchmark HGC2 DAC, and Anthony Gallo Strada 2 Speakers plus sub.

[Julf]

We have sound!

Great!

[jtwrace]

We have sound! It sounds so good I could cry.

My setup is with the Benchmark HGC2 DAC, and Anthony Gallo Strada 2 Speakers plus sub.

Excellent!  Lets see some pics of the finished amps.   

[zenpmd]

Hi guys. So I remain a bit confused, despite having a working amplifier. Can you help?

I see people attaching either or both the IEC inlet and the XLR connection to the chassis. Why is this?

I also see people connecting the screw in the very corner of the power supply to the chassis, why is this?

What is the purpose of the inlet next to pin 1 on the XLR?

I want class 2, and I figure a lot of this relates to non-class 2 set ups but I want to make sure I am doing it right.

Thanks

[Julf]

I see people attaching either or both the IEC inlet and the XLR connection to the chassis. Why is this?

IEC inlet to chassis is safety earth - absolutely needed unless you are sure your installation conforms to Class II requirements, and a good idea even then (for safety reasons). XLR connector to chassis it to ground both the chassis and the cable shield to signal ground.

I also see people connecting the screw in the very corner of the power supply to the chassis, why is this?

Grounding/earthing the power supply to the same signal ground as the chassis.

What is the purpose of the inlet next to pin 1 on the XLR?

Not sure which inlet that would be. Pin 1 should be connected to chassis using the shortest possible lead, and often the chassis of the XLR connector has a connection pin too - that should also be connected to pin 1.

I want class 2

Why? And do you know what that requires?

Don't take it the wrong way, but if you are asking questions like this, you might not be familiar enough with ground/earth practices, isolation distances etc. to make sure your installation fulfills all  class 2 requirements - with, in worst case, lethal effects.
 
Class 2 is all about electrical safety, not sound quality.

[Speedskater]

'Juff's' post is exactly correct!
But we should not:
IEC inlet to chassis is safety earth - absolutely needed unless you are sure your installation conforms to Class II requirements, and a good idea even then (for safety reasons).
An installation is not Class II unless a safety agency certifies that it is!
Many finished Class II components should not be modified to connect their chassis to Safety Ground/Protective Earth.

[Julf]

An installation is not Class II unless a safety agency certifies that it is!

Absolutely - and I don't think any of us bother to get any sort of formal approval. It still makes sense to try to follow the safety guidelines, and grounding the chassis is usually a good precaution, unless you really, really know what you are doing.

[zenpmd]

To be clear, I have attached to this message the wiring I have done.  I have omitted the speaker cable as that is simple, but other than that there is NO OTHER wiring anywhere.

If I am not opting for class 2, what should I do to make safe?

Second photo is of XLR connector. You can clearly see the 3 pins. But what is that inlet and do you do anything with it in the bottom right corner?

Thanks!

http://postimg.org/image/mawxgyzsb/

http://postimg.org/image/lizv3a0wl/

[Julf]

To be clear, I have attached to this message the wiring I have done.  I have omitted the speaker cable as that is simple, but other than that there is NO OTHER wiring anywhere.

So you are connecting mains earth only to nAMPON? Yikes!

If I am not opting for class 2, what should I do to make safe?

Follow figure 2 in the paragraph 12.3.1, "Vastly preferred setup: XLR input" on page 12 of the NC400 data sheet, but connect the mains earth (the 3rd pin of the IEC connector) to the chassis.

Second photo is of XLR connector. You can clearly see the 3 pins. But what is that inlet and do you do anything with it in the bottom right corner?

It is the connector chassis. If the connector chassis is metal, and already touches your metal enclosure, you don't need to do anything with it, otherwise you want to connect it to signal ground or the chassis with a (short) lead.

[zenpmd]

What is wrong with connecting Nampon to mains earth? Where should it go?

That paragraph you mention suggests that pin goes to chassis and shield of the input cable to chassis? Why?

Why should I connect the XLR inlet to the chassis as well?

This is what I don't understand no one gives a reason for anything and it profoundly confuses me!

[Julf]

What is wrong with connecting Nampon to mains earth? Where should it go?

Your power supply ground. Mains earth might not have any real relation to that, and in worst case might have transients (from electric motors, dimmers, fans etc) that fries your nAMPON input.
 

That paragraph you mention suggests that pin goes to chassis and shield of the input cable to chassis? Why?

Bot chassis and input cable sheath go to signal ground to shield the signals from external noise and to conduct any ground/earth currents. Mains earth is connected to chassis so that if you have a short circuit somewhere, you blow a fuse instead of making the chassis carry a high voltage that might kill you.

Why should I connect the XLR inlet to the chassis as well?

Because it is a protective enclosure (from an EMF point of view) for the signals, just like your amp enclosure and the cable sheath.

This is what I don't understand no one gives a reason for anything and it profoundly confuses me!

I am sure we are all more than happy to answer questions and explain. The Hypex datasheets understandably explain the specifics of the modules, but assume general knowledge of electrical circuits, grounding practices and induced noise.

[zenpmd]

Julf

I know its a big ask, but can you do a diagram like I did both

1. a class 2 set up (ignoring all the insulation and other safety requirements - just the wiring)

2. and a traditional wiring?

I just find it very hard to follow the words as we all use slightly different ones for the same thing, etc

[Julf]

Julf

I know its a big ask, but can you do a diagram like I did both

1. a class 2 set up (ignoring all the insulation and other safety requirements - just the wiring)

Sure, but there really is no need, as Hypex has done it for you. It is figure 2 in the paragraph 12.3.1, "Vastly preferred setup: XLR input" on page 12 of the NC400 data sheet:



(I hope Hypex doesn't mind the snapshot from their manual)

2. and a traditional wiring?

The only difference is a connection from mains earth (the 3rd pin of the IEC connector) to the chassis.

[zenpmd]

Thanks Julf.

Where is Nampon in that diagram?

So the difference between that and mine is that their audio input shield goes onto the case, whereas mine is going into pin 1. And I have not made pin 1 go to chassis.

The inlet thing I mentioned above is not on their diagram?

What is the purpose of pin 1 to chassis?

[Julf]

Where is Nampon in that diagram?

Connect it to the shield of the input wire.

So the difference between that and mine is that their audio input shield goes onto the case, whereas mine is going into pin 1. And I have not made pin 1 go to chassis.

Right. Just like you want the shield of the input cable connected to signal ground, you also want the chassis connected to signal ground.

The inlet thing I mentioned above is not on their diagram?

No. Because some connectors have it, some not. It should connect to the chassis and (either via the chassis or directly) to signal ground.

What is the purpose of pin 1 to chassis?

To shield the signals from external noise and to conduct any ground/earth currents.

[zenpmd]

OK, thanks Julf. I think I am slowly understanding now.

My plan is therefore to:

1. Solder together Nampon, Audio Input, and Sheild together, and then thread that wire through the xlr connector chasis and then solder to pin 1.

That way, nampon, audio input, sheild and connector chassis in xlr are connected to pin 1.

My xlr connector is metal, the neutrik one from the hypex website, so I dont need to connect it to chassis, right?

And then I am done.

I then have the option for traditional wiring or to meet class 2.

I am using the silicon ray case, so the air of at least 6mm inside the case works from that pespective. What else is needed for class - heat shrink mains cables, etc?

[Julf]

1. Solder together Nampon, Audio Input, and Sheild together, and then thread that wire through the xlr connector chasis and then solder to pin 1.

That way, nampon, audio input, sheild and connector chassis in xlr are connected to pin 1.

I assume you meant "audio input shield" and not soldering the audio input to ground

My xlr connector is metal, the neutrik one from the hypex website, so I dont need to connect it to chassis, right?

I would still make the connection, just in case - even if the connector-to-chassis connection is made through the metal chassis of the connector to the chassis, different metals and different surface treatments sometimes make the connection less than perfect.

I then have the option for traditional wiring or to meet class 2.

I am using the silicon ray case, so the air of at least 6mm inside the case works from that pespective. What else is needed for class - heat shrink mains cables, etc?

I am not sure I am comfortable giving instructions for achieving class 2 electrical safety on a public website. Too many ambulance chaser lawyers out there. Is there a reason you don't want to use safety ground?