NCORE MP Build using Ghentaudio Kit.

[john61ct]

you seem to be at the very beginning of your travel in understanding all this stuff.

Well I sure am and no shame.

> So my advise would be to buy one FAxx2 plate amp, put all the boards in an aluminum box, and you will have a nice stereo amplifier with DSP in order to do some room eq

My understanding is none of these plate amps are stereo, only one channel input?

So could someone ELI5 how to avoid having to buy two of them?

I am driving a pair of LS50s, not building any speakers. Need to accommodate both analog and digital sources.

Would like to add a sub one day, but budget is very limited.

TIA

 

[ChrisB1224]

Removing pops/clicks at power on/off

I ran some tests today to verify the theory that asserting Mute (J4.13 or J4.4) on power up and power off will solve the problem.

It does work to completely remove the power on/off pops and clicks.

This requires keeping the +5V standby power always on for control to make this will work. With this method, the AC mains will remain on and the +5V standby supply will be used to manage the main power on and off behavior. I suspect that some commercial builds use this method with front panel switches. A prior post of mine estimated the quite small cost of leaving this on 24/7.

The next step is to build a prototype with an external +12V trigger input and an optical isolator and a Schmitt trigger inverter IC. Timing information from Hypex data sheets indicate that simple logic with no delays will be fine since Mute is faster acting than turn on/off.



View attachment 56090

I need to do this. The power up and power down pops/transient energy is really bothering me in an otherwise solid build. I have a 3 channel nc502mp+nc500mp build. I have a 12 volt trigger
I did not build the amp. I have basic knowledge, can solder, but I was wondering if you could help break this down to the point where its idiot-proof! I could wire one of these devices together but once you step outside of the main build that I've seen a thousand times, I need some help.
Would you consider this? Thanks.

For reference, I have a ghent 3 channel case with triggers in and out that we're drilled out. I have tried every combination of startup and shutdown and it just doesn't matter, I get pops every time. When I use the trigger, I get a weird buzz on shutdown, but it isn't as loud as the pops. Most of the startup and shutdown noise comes from my center channel(center is on the 500mp. Also, it's possible my preouts help with this. My avr let's me turn off the internal amps, but just for the mains or all 11 channels).
I've got a power conditioner that I got on ebay because it's triggered and powers everything on. High current switched startup delay x2, and regular switched shutdown delay x4. Pops with either of these options on startup and shutdown. Also pops with 12v trigger input, and when just turned on normally. Order of components doesn't matter.
Sorry for the length. Thank you everyone

 

[Julf]

I need to do this. The power up and power down pops/transient energy is really bothering me in an otherwise solid build.

Does it also pop with no preamp connected (so nothing connected to inputs)?

 

[ChrisB1224]

Does it also pop with no preamp connected (so nothing connected to inputs)?

Yes, which is the weirdest thing. Also, the 12v trigger in...according to the amp-builder...the trigger is suppose to activate the 5w standby, but I get some static in the tweeter when the 12v goes from avr to amp.
At this point, I'm just going to leave it on 24/7. Do you think it will overheat if I do this? The pops are fairly loud

Edit: I have had it in for about 30 minutes without using it. Preamp is also on, and the amp is cool to the touch, which seems like a good sign if I want to leave it on all the time, but ill have to stress-test it a bit and see if it cools back down after getting hot, which it should. I could also look into a cooling solution if I need to. I'm fine with that.

I don't like that static I got with the 12v trigger though. Seems like figuring that out could also be a solution, as the pops are much lower with the trigger

 

[thepiecesfit]

I also get thumps and pops with my NC502MP. The initial speaker thump is when the inrush of power comes into the amp. My AVR takes about 10 seconds to fully come online then there is a second pop from the tweeters. I was thinking at least if swapping out the relay in the amp with a 10 second delay it would take care of that final pop. Hoping for a more elegant solution. Nord appears to have a micro controller linked to the power button that mutes and slows down the amps from turning on, I'm sure someone more knowledgeable can reverse engineer this and provide a solution. I'd like to get this amp silent if possible, do have some longer term concerns about damage to the speakers.

 

[Julf]

I assume the buffer is still DC coupled?

 

[ChrisB1224]

I also get thumps and pops with my NC502MP. The initial speaker thump is when the inrush of power comes into the amp. My AVR takes about 10 seconds to fully come online then there is a second pop from the tweeters. I was thinking at least if swapping out the relay in the amp with a 10 second delay it would take care of that final pop. Hoping for a more elegant solution. Nord appears to have a micro controller linked to the power button that mutes and slows down the amps from turning on, I'm sure someone more knowledgeable can reverse engineer this and provide a solution. I'd like to get this amp silent if possible, do have some longer term concerns about damage to the speakers.

That would be ideal. Hypex themselves claim there is no need for extra protection...of course.
The first few days I had the amp, the pops were a bit annoying.
I do not use the 12v trigger on my amp, as it increases the noise floor on my center. There must be some sort of crosstalk, because it only happens with speakers that don't yet have the avr internal amps shut off. Very weird, maybe a better shielded mini mono would work. I would also get this unpleasant buzz when turning it off via trigger.

What I do now is use the Panamax mp5100. I got it on ebay and has a delayed turn on for its high current slots, and immediate turn off. Triggered by the avr. The transient energy doesn't seem to be much, as it is less of a pop, and more of a "hello sir, I'm awake now". And upon shutdown, it's not like the weird noise i get from the trigger. So, the force of the pops are nowhere near what I was once getting.
Startup is clean with this timer. Shutdown is a bit less so, but it doesn't alarm me like the pops I was getting with the trigger when I first plugged it in.

 

[Jungstar]

Or to a FA122 fusion plateamp: https://www.diyclassd.com/product/fusionamp-fa122/92
275€ tax excluded

Why is the plateamp better value. It also includes DSP , right?