Newbie Help - Ncore build

greenkiwi · « **Reply #60 on:** 28 Jul 2014, 04:54 pm »

Looking forward to hearing your results.

Toaster · « **Reply #61 on:** 30 Jul 2014, 04:56 pm »

Got 'em all going. Can't really add much to previous positive reports. Clean, powerful, no noticable character, no spurious noise, switch on and off is perfectly civilised, heat doesn't seem to be an issue. very nice! The nearest I can get to audiophilia is to say that the clarity helps to differentiate tonal colours and stereo placement and there seems to be a greater sense of momentum to music that is supposed to sound propulsive. Musical dynamics also seem more expressive and obvious. This is all just anecdotal though, even though these are my impressions I wouldn't like to try to quantify them! The overall impression is more like music and a bit less like hi-fi, which is a good thing.

Julf · « **Reply #62 on:** 30 Jul 2014, 06:07 pm »

Good to hear!

As to descriptions of sound quality, the only one I want to hear is "it doesn't color or distort the sound in any audible way"

zenpmd · « **Reply #63 on:** 30 Jul 2014, 09:14 pm »

Hi Everyone

I am back, the clueless idiot who started this thread who, after a long period travelling, can finally get these amps up and running! Just some things I wanted to check now I've looked at things again:

1. Twisted speaker cable. I assume you just twist and put a cable tie or similar to hold in place. I assume this doesnt mean you have to strip all the way back and twist and that you just twist in its insulated form?

2. Speaker connections on amp. Am I right in saying it connects to the underside? Between the square nut and the underside of the connection? How do you determine positive or negative? No marks on my speakers to follow it all the way through.

3. J9 on the amp, is the input from the DAC, right? I ignore the thin cable and split the thick one, connecting to two connections in balance output on the case, right? But which two? I still havent worked this out.

4. J1 on the SPMS I dont connect right?

5. J3. Power in. I have a brown and a blue cable. I have L and N, and will ignore G as I am doing class 2 with correct clearances. But which is L and which is N, the brown or the blue?

Thanks everyone, any help much appreciated!

Julf · « **Reply #64 on:** 31 Jul 2014, 05:46 am »

Quote from: zenpmd on 30 Jul 2014, 09:14 pm

1. Twisted speaker cable. I assume you just twist and put a cable tie or similar to hold in place. I assume this doesnt mean you have to strip all the way back and twist and that you just twist in its insulated form?

Twisting the uninsulated part would short the cables! Only strip the minimum amount you need to connect the cable ends, twist the rest.

Quote

2. Speaker connections on amp. Am I right in saying it connects to the underside? Between the square nut and the underside of the connection?

No - between the square nut and the top, so that the screw can apply force to the cable.

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How do you determine positive or negative? No marks on my speakers to follow it all the way through.

On the nc400, positive is closer to the outer edge. As long as you are consistent with both (all) channels, absolute phase doesn't matter.

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3. J9 on the amp, is the input from the DAC, right? I ignore the thin cable and split the thick one, connecting to two connections in balance output on the case, right? But which two? I still havent worked this out.

The thin cable is nAMPON - if you ignore it, the amp will not turn on. You have to connect it to ground. Pin 1 is non-inverting and pin 2 inverting input - again, absolute phase doesn't matter, so yes, connect them to the balanced outputs of your DAC.

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5. J3. Power in. I have a brown and a blue cable. I have L and N, and will ignore G as I am doing class 2 with correct clearances. But which is L and which is N, the brown or the blue?

Brown is L and blue is N.

zenpmd · « **Reply #65 on:** 31 Jul 2014, 02:06 pm »

Thanks Julf. I think this makes sense. I will take another look tonight.

In the mean time, I've lost one of the insulated mounts for the power supply. Any idea what I can use as a substitute to act least get up and running?

Julf · « **Reply #66 on:** 1 Aug 2014, 11:52 am »

Quote from: zenpmd on 31 Jul 2014, 02:06 pm

In the mean time, I've lost one of the insulated mounts for the power supply. Any idea what I can use as a substitute to act least get up and running?

Where are you based? Anywhere that is served by any of the overnight-delivery electronics supply companies (RS, Farnell/element14, Conrad, ...)?

As a temporary measure, anything that isolates will do (plastic, wood etc).

jtwrace · « **Reply #67 on:** 1 Aug 2014, 11:55 am »

Please remember to post pictures for all to see. Peeps love pics!

zenpmd · « **Reply #68 on:** 3 Aug 2014, 03:08 pm »

So to confirm (I am just about to solder):

On the XLR connection, white is positive, and that goes in no2. on the XLR and blue is negative and that goes in no3. right?!

zenpmd · « **Reply #69 on:** 3 Aug 2014, 03:39 pm »

I am getting really pssed off and wish I never started this project to be honest. Hypex instructions are as clear as mud, and I dont understand why nowhere will even tell me how to wire the XLR.!!!

Pulling my damn hair out and not enjoying myself

zenpmd · « **Reply #70 on:** 3 Aug 2014, 04:05 pm »

OK I have finished wiring I think. Can someone take a look and tell me whether I can now connect up and switch on?

zenpmd · « **Reply #71 on:** 3 Aug 2014, 06:49 pm »

I switched it on, but nothing. Checked signal to DAC and its fine as headphones work. Speaker just gives out a hum. Any ideas? Thanks

jtwrace · « **Reply #72 on:** 3 Aug 2014, 06:51 pm »

Quote from: zenpmd on 3 Aug 2014, 06:49 pm

I switched it on, but nothing. Checked signal to DAC and its fine as headphones work. Speaker just gives out a hum. Any ideas? Thanks

Do the lights come on the NC400?

zenpmd · « **Reply #73 on:** 3 Aug 2014, 07:08 pm »

There is one red light?

jtwrace · « **Reply #74 on:** 3 Aug 2014, 07:13 pm »

Quote from: zenpmd on 3 Aug 2014, 07:08 pm

There is one red light?

It's been a very long time since I've had NC400's but there are lights so that's a good sign.

Pin 2 is hot on the XLR. You need to make sure that you have that correct. Also, the black wire that's on the input loom goes to chassis ground. Make sure that's connected as is the XLR ground to chassis.
Also, make sure the ribbon cable and other loom with the large molex connectors is really seated into each module (NC400 & SMPS).

MAKE SURE UNIT IS UNPLUGGED!

jtwrace · « **Reply #75 on:** 3 Aug 2014, 07:20 pm »

All the info is in the datasheet.

If you have a DMM and check continuity it's really simple.

Lets get it working first and then we can tidy up the build a little. You want the speaker wires on the NC400 to enter the posts from the same side.

srb · « **Reply #76 on:** 3 Aug 2014, 07:27 pm »

I would also check that your speaker output binding post insulators are correctly installed and working so that there is no short to ground through the chassis.

Steve

zenpmd · « **Reply #77 on:** 3 Aug 2014, 07:28 pm »

that diagram is meaningless, as there is no way of telling which cable comes from each pin!?

What is pin 4? There are only three cables coming from that connection: positive, negative and Nampon. And hypex does not even seem to say which out of the blue and white is positive (hot) or negative (cold).

What I have done is as per the photo, I cant really explain it because I have no idea what I am plugging where, as Im doing everything by rote.

zenpmd · « **Reply #78 on:** 3 Aug 2014, 07:28 pm »

Quote from: srb on 3 Aug 2014, 07:27 pm

I would also check that your speaker output binding post insulators are correctly installed and working so that there is no short to ground through the chassis.

Steve

Thanks Steve but I have no idea what this means?

jtwrace · « **Reply #79 on:** 3 Aug 2014, 07:43 pm »

That diagram is all you need! Did you use a DMM as I suggested? That will help you a bunch.

Also, there are four wires in that loom. Blue, white, black Nampon and the shield. You need them all.