One power supply upgrade - source or pre?

Source first. So it has to be the NDX.  Can your HC be DR'd ?

Thanks. I should have mentioned that the HC is DR already. 

Even more reason to get that lovely 555 then ????

I know it makes sense! 

NDX2?

I would improve the source, I think my 282 is well matched with a HCDR. 

That is perhaps my next cunning plan. At the moment I am still really happy with my NDX and I can imagine an NDX 2 on the horizon in which case the PS certainly won’t go to waste. NDX 2 first would be a cheaper route of course which has its own temptations. 

555. It will future proof your move up to NDX2 / NDS or beyond if you decide to later.

Thanks all. That helps in sorting out my thinking. Much appreciated. 

The NDX responds well to both the XPS and 555 I tried both in my system. A lot depends on future upgrades the 555 is more future proof as previously stated.

555PS for your NDX. Should be more fun than putting a SuperCap on 282 

Can you compare your NDX with a 555PS with an NDX2 and make your decision from there ?

Hicap DR on a stageline is a very significant upgrade which you wouldn’t get with the 555 route. I would (and probably will given I have a similar system) swap ndx to ndx2 and supercap on 282

I would consider consider nDAC or Hugo on NDX if not NDS/555DR. 

Chag - 

Having had the same system, I can confirm a PS on the NDX is the way to go. Even with an XPS, it becomes another source entirely.

If the NDX has the functionality you already want, I'd suggest hanging onto it and do an NDS when one shows up at the right price; an ND555 in the much later future, or skip a generation entirely and do an NDX3 in 6 or so years. As far superior as the NDX2 is, I'd not replace a component with simply the current version at the same level. It's a bit like successively buy the current Ford Focus and calling each one an upgrade. It is better but also in another aspect, sideways. Always go up the ladder.

And take several rungs at once, 555ps next.

Thanks for the advice everyone. That really helps. My conclusion is to keep open the upgrade route as I usually prefer a significant upgrade and so the 555ps does indeed seem the way to go for that reason. That will be ordered and with me soon.