hypex ncore

[mr_push_pull]

isn't the NCORE low-pass filtered already? actively, indeed.

[3lviz]

I guess then the hf garbage is attenuated twice.

[mr_push_pull]

depends if the active stage can handle it.

[3lviz]

How come?

If i have understood right and the frequency response on the datasheet is from the nc400 input filter (not output filter or the source device's output filter) and the response (or rather the filtering) continues with similar Q after 100 khz too, it attenuates the input around 20 dB near the switching frequency (480khz). The added RC-filter does preliminary 24 dB attenuation near the switching frequency.

[3lviz]

To my knowledge, at worst, no harm done. At best, an improvement.

[robbbby]

My one amp channel is still giving me problems. Sometimes it cuts in and out, other times there is no music at all. However I realized today, when it cuts in and out, or goes completely silent, I can still put my ear up to the tweeter and hear the music, it sounds like it is playing an un-amplified signal.

My tweeter is dead silent when my good amp is on but without music playing. My other speaker that is hooked up to the problematic amp has white noise on the tweeter, and that is with the input cable both plugged in or disconnected. Also with the input cable both connected or disconnected the speakers will make occasional random "blip" types noises.

I've already talked to hypex support and I don't want to pay $120+ to ship the module back, so I was hoping somebody here may have some suggestions. From what I understand it is not OVP. The OVP will usually generate an audible clicking noise at the amplifier, I am not getting anything like that.

[ua100k]

Originally Posted by robbbby

My one amp channel is still giving me problems. Sometimes it cuts in and out, other times there is no music at all. However I realized today, when it cuts in and out, or goes completely silent, I can still put my ear up to the tweeter and hear the muserzic, it sounds like it is playing an un-amplified signal.

This means NAMPON is being triggered. There is high frequency signal flow though as the NAMPON only turn the stage off and it is not a complete signal cut off.

NAMPON has to be zero for your amp to be on. Any "perceived" voltaged and the unit goes off. Would suggest clean up wiring before you send it back to see if the problem goes away. Or remove any wire connections to NAMPON on the NC400

[Julf]

Originally Posted by ua100k

NAMPON has to be zero for your amp to be on. Any "perceived" voltaged and the unit goes off. Would suggest clean up wiring before you send it back to see if the problem goes away. Or remove any wire connections to NAMPON on the NC400

Good suggestions. Robbbby, how is your NAMPON (pin3 of the audio input connector, J9) connected?

[Larsas]

Originally Posted by Julf

Good suggestions. Robbbby, how is your NAMPON (pin3 of the audio input connector, J9) connected?

Had exactly this problem with one of my nCore monoblocks, discovered I had made a mistake soldering the XLR connections (mixed up pins). Resoldered and problem gone, no harm done.

[robbbby]

Originally Posted by ua100k

This means NAMPON is being triggered. There is high frequency signal flow though as the NAMPON only turn the stage off and it is not a complete signal cut off.

NAMPON has to be zero for your amp to be on. Any "perceived" voltaged and the unit goes off. Would suggest clean up wiring before you send it back to see if the problem goes away. Or remove any wire connections to NAMPON on the NC400

The wiring that I had shown you when you were trying to help me troubleshoot via email has been removed. The only thing I have left now is nc400 input cable, jumper cable between nc400/smps and AC supplying smps, it's just the basics with a 120V switch on the back to turn it on. Still the same problem.

Originally Posted by Julf

Good suggestions. Robbbby, how is your NAMPON (pin3 of the audio input connector, J9) connected?

It is connected to the shield of the input cable, which is connected to pin1, which jumps to the outer metal tab of the xlr connector and jumps to my chassis which is also connected to earth. So pin1 shield is common to nampon and the entire chassis.