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NAD C 399 HybridDigital DAC Amplifier

@diddley I dont see the point to soldier it out cuz now the amp works amazing

@Sved P there is no science behind your words, where are your measurements from my amp? this is a site for facts and controlled tests and I respect that

I just posted what I did and I know I am losing the warranty on my 3 years old amp

Only what I want to say is that those fastons I could easily move left/right and thats not good connection
 
Start reading here

 
I am attaching the picture of internal components from C399,

what I did on mine is that I have soldered all (power) wires coming from the plug and coming on to supply board...

on the pic marked with circles

why I did it its because they are not making good connection (its maybe ok for the LED lights but not for the amps) especially the one on the supply board...you can check it by removing that white plastic molex and you`ll see that when you put the wire in to connector on the board, its moving easily which is making additional resistance, resulting with less microdetails and boomy bass

After I did this tweak the sound is now very fast and tight with more soundstage and microdetails, it feels like the speakers got more power and grip

hope this will help who ever will try it
A Molex connector like that is usually rated for about 3 amps. On 230volts that would equal about 700 watts of power before things start to melt. Ive hooked up a power consumption meter on the amp. It rarely consumes over 50watts of power.

The original design is sufficient. The odds of your modification being audible are zero.
 
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Guys, you didnt read what I am pointing on... forget that molex connector and all this links

I am saying that its sad to see a good amplifier with a poor connection on the power supply side...I am not mentioning any poor connector that is not suitable for this amp

As I dont have any spare parts and I am not trying to invest more money into it, I decided to solder those connections and I came with very nice results

I posted this so maybe it will help some other guys here, if this is not the right way please delete all what I wrote here
 
I am saying that its sad to see a good amplifier with a poor connection on the power supply side
That's just nonsense. Here is a 2kW amp with similar connections:


As can be seen here:


There doesn't seem to be any negative impact on performance.
 
thats not NAD C399

Maybe we can just wait for someone with the NAD C399 who can open it and confirm the same

Again I am not talking about the type of connection, I am talking about how poor I found it in my amp NAD C399
 
I am saying that its sad to see a good amplifier with a poor connection on the power supply side...I am not mentioning any poor connector that is not suitable for this amp
So what are you saying? It's not a poor connector, however you removed it anyway to improve the connection?
 
thats not NAD C399
Does it matter? It's a similar Molex connector, that's used in lots of amplifiers. Never has anyone proven that soldering them makes any difference whatsoever.
 
The most powerful amps I have seen (current too) had a 4-point JST connection for mains,with the inner 2 ones unconnected (probably for support) .
You DON'T solder mains if the company hasn't done it already at their own way and responsibility.
 
Read again what I am trying to say,

If fastons are done right probably it will not make any difference soldering them

But in my case fastons are not tight
 
If the connection truly was (too) lose, it would have resulted in the amplifier shutting down randomly or sparks and smoke...

Ive checked the connectors on mine, they're perfectly fine. There's allot of issues with NAD products in their current line up. This is not one of them.
 
ok thanks for checking... to be more precise on mine they were good enough to not cause any issue but I could move them each with the finger

Please check this video, you will get it better
Starting at 0:10 the first black wire on the video was exactly like on my amp blue/brown wires

 
ok thanks for checking... to be more precise on mine they were good enough to not cause any issue but I could move them each with the finger

Please check this video, you will get it better
Starting at 0:10 the first black wire on the video was exactly like on my amp blue/brown wires


Those are 12V batteries, lower voltage thus high current. Hence why car jumper cables are so thick.
 
Nope, I agree, but I did it because I dont want to think about it anymore

Probably there is many more out there with the same issue which can be fixed easily
 
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Never mind that the solution isn't soldering ;)
Yep.
There are really nice locking crimps out there,with such a strong grip enough to take a blast with the only caveat the difficulty to unconnected them sometimes.
 
It could be defined as poor quality control...

Nowadays almost everyone uses faston connections (also found on washing machines etc.) the problem that the user says is that they were simply very loose, if they had been well fixed they would not have given any problem (not even psychological) some have the locking tab and are more stable, but seeing them so slow is not a good thing even if it has no influence on the performance.

Consider that class "D" amplifiers do not have the same high absorption as class "A-B" ones

I happened to see the same thing on 2-3000 euro speakers! the slow and weak contact, I simply tightened them with pliers.

Among other things, putting "faston" is a more expensive solution than the simple soldered wire... go figure.
 
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