Hypex NCore NC500 build

[Julf]

Do you have a picture or schematic of how your amps are wired up?

And considering the ncores are DC coupled, could it be that your DAC puts out a DC component that biases the amps to near clipping?

 

[diyaudnut]

Do you have a picture or schematic of how your amps are wired up?

And considering the ncores are DC coupled, could it be that your DAC puts out a DC component that biases the amps to near clipping?

Balanced cable wiring is according to the Hypex datasheet and appnotes.

DC is a possibility, but i notice the issue with ucd400hg as well which is not DC coupled. Also the DC on the DAC output is around 30mv.

couple of observations on the XLR connections.

The DAC has 4 IV boards, each feeding 2 XLR connectors on the DAC chassis. Connection from the boards to the XLRs on the chassis use balanced shielded cable. Shield goes from gnd on the board to pin1, pin1 on the XLR is also shorted to the chassis.

on the amp end, XLR input pin 1 connects the shield to amplifier chassis. The connector to the amp modules is the Hypex provided balanced input cable.

The DAC outputs spans to 4 amplifier chassis each holding 2 amp channels.

Could this be creating GND complications?

 

[diyaudnut]

Do you have a picture or schematic of how your amps are wired up?

And considering the ncores are DC coupled, could it be that your DAC puts out a DC component that biases the amps to near clipping?

I could notice this on a scope. Trying to get hold of one.

 

[Julf]

The DAC has 4 IV boards, each feeding 2 XLR connectors on the DAC chassis.

And the IV boards have balanced outputs?

 

[diyaudnut]

And the IV boards have balanced outputs?

yeah they have balanced outputs.

 

[Julf]

yeah they have balanced outputs.

OK, then your wiring should be OK.

 

[diyaudnut]

The distortion is audible at certain volume level from the DAC. If you had a chance to listen to the sample, does it sound like anything you have experienced before?

 

[Julf]

The links don't work for me.

 

[diyaudnut]

sorry. they probably expired.
Could you try this
https://drive.google.com/open?id=0B7X-dOhSii2xUmtEVXBzOEFnbUE

https://drive.google.com/open?id=0B7X-dOhSii2xRVNXRVZYeDVKV28

 

[TNT]

Why not start a thread "Building NC400 based amp"?

//

 

[bavmike]

If a thread was made dedicated to NC-400, rather than general Ncore amps, chances are it would stay on topic better.

 

[ds23man]

http://www.diyaudio.com/forums/class-d/302602-ncore-diy.html#post4960346

 

[Julf]

sorry. they probably expired.
Could you try this
https://drive.google.com/open?id=0B7X-dOhSii2xUmtEVXBzOEFnbUE

https://drive.google.com/open?id=0B7X-dOhSii2xRVNXRVZYeDVKV28

Will reply in the nc400 diy thread.

 

[IgorZep]

Also the DC on the DAC output is around 30mv.

Is is common mode or differential mode DC? Meaning are you measuring it between two signal wires or on each of them re. chassis/ground? Common mode DC can also cause clipping of input stages if it is too excessive.

 

[diyaudnut]

I checked again.
DC offset on each signal wire of the balanced pair on the DAC output is around 178mv. But common mode DC is almost 0.

 

[diyaudnut]

Igor,

Please continue any post on the diy thread created above

http://www.diyaudio.com/forums/class-d/302602-ncore-diy.html

thanks

 

[berga12]

Hi guys
I've an issue,I'm not able to turn ON the Ready LED,I can't understand what I'm doing wrong!
And suggestion?

 

[bavmike]

Hi guys
I've an issue,I'm not able to turn ON the Ready LED,I can't understand what I'm doing wrong!
And suggestion?

I would talk to Hypex support. Since you must be an OEM client of their's in order to obtain those amps, they will be glad to help.

 

[Antana]

I would talk to Hypex support. Since you must be an OEM client of their's in order to obtain those amps, they will be glad to help.

Or he bought it from an OEM [emoji1]

 

[bavmike]

Or he bought it from an OEM [emoji1]

Most likely. Doesn't look like any of the commercial build I've seen.