12-volt-only motherboard and linear power supply?

[Superdad]

Most all of the current Intel NUC motherboards will run from just a 12V supply.

 

You are much better off putting the supply external to the case.  But then I am biased as I build and sell a popular choke-filtered, dual-output, 5-7 amp LPS.  

 

Also, having the DC-DC switching converters on the motherboard does not offer much advantage over choosing the ATX mobo you want and plugging in a picoPSU to drop the 12V to 5V and 3.3.  Comes complete with the harness and everything.

 

 

[Superdad]

12 hours ago, Bullwinkle said:

This is actually the route I've taken over the past couple of weeks (a good quality LPS outside the case, feeding a small dc to atx ps inside the case, which in turn feeds the atx mobo I want).

 

That's great.  Gives you more flexibility in the long run. 

[Superdad]

2 hours ago, simonklp said:

 

I am thinking of building a Audio PC. Could anybody be so kind to give me some advice on which of the following is a better option in terms of SQ: -

1) To use a ATX Linear Power Supply with ATX motherboard.

2) To use a 12V DC LPS with motherboard capable of accepting 12V input.

 

The dilemma here is that, while on one hand, there are some very good 12V DC LPS available in the market, there is only very limited choice for ATX LPS. Furthermore, in terms of specifications and reputation, it appears that some 12V DC LPS are much better than the ATX LPS.

 

But, on the other hand, as mentioned above by @Superdad, having the DC-DC switching converters on the motherboard may have adverse effect on SQ when compared with the ATX mobo together with a dedicated DC-ATX converter for Hi-Fi (e.g. HDPLEX).

 

Could anyone kindly give some advice on the above?

 

Thanks! 

 

 

A couple of things to keep in mind (and I promise I am not saying this to sell more of our choke-filtered, dual-output, 5-7 amp JS-2 LPS units--we already sell all we can build);

 

a) The "ATX" linear supplies, just like standard SMPS ATX supplies are still feeding 12V (and 5V) into both the 20/24-pin power socket and the 4-pin higher-current 12V socket of the motherboard.  So the DC-DC switching converters of the motherboard are used regardless of if you power the mobo thru a back-panel facing 12V/19V DC jack or the main board connection.  

 

b) The various picoPSU-type adapters (and I see now that HDPlex has expanded into that space with adapters smaller than their big version) are all still DC-DC switching regulators.  I know that the wiring harness of the 12V picoPSU units splits out the 12V to the square 4-pin socket for main CPU supply (which still goes through a bunch of DC-DC regs as no chips actually run from 12V).  So I never really followed the point of using a 19V input adapter other than perhaps to reduce the current requirement to provide the critical 12V going to the mobo.

 

c) As for the other voltages: If one is building a system, then you ought to consider supplying 5V--to things like SATA drives and USB cards--directly from an LPS.  That is better than going through the DC-DC switching regs of the adapter boards.  The wiring for such is not difficult, and these days most modern motherboards are not fussy about power-on sequencing.

 

So it seems to me that one can either keep things simple with a 12V input NUC-type board, or with a simple 12V picoPSU  wth the harness it comes with: