Thanks VB, as always! 
I don’t know whats changed, as before when I tried the MiniDSP into the CA A5 amp, it had the same problems although today, no issues at all.
For the moment, everything else seems to be working so I’ll not touch anything… 
As the old Hi-Fi Bluffer’s Guide said - “Trying to remove hum is guaranteed to drive you to the edge of insanity”
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I had hum in the bass,it’s now moved to more of a whine in the mid on one channel
Dont know if a valve is on its way out,or something else
I deleted the post as I thought I solved it but being a bit of an idiot and unplugged the wrong component and skewed the results.
Basically still having a pink noise hum issue when using high efficiency tweeters with and without a MiniDSP 2x4 HD. Long story short, appears to be coming outside of the hifi causing it so need to investigate further. And I’ve moved house since the OP.
Suspect it’s the fridge or one of the many SMPS devices around the house.
Can you borrow a mains filter to see if it’s coming along the wiring or if it’s radiated through the air ? Otherwise it’s just a matter of turning stuff off and on, obviously. I once sat with a system (not mine) that was clicking every time the owner’s neighbour’s central heating 'stat went on and off.
That really does sound like a dying valve. Had the same a couple of days ago with a valve in the pre. Annoying as it happens WAY too often for my wallet’s liking…
I lost interest after the first graph from 2019, but that showed both a 50Hz spike (obviously mains related), and a whole chunk of noise peaking at 5K, which could have been switchmode noise, or pickup from a digital source of some kind.
Your problem is figuring where the noise is originating, then whether it’s actually being radiated or conducted (or both…).
The mains noise doesn’t suggest an intrinsic problem with mains quality, rather that 50Hz power either is being radiated from one source to a gain stage somewhere or isn’t being filtered properly (or both…). You may (e.g.) have a saturating transformer in a linear PSU (could be overvoltage, or ‘DC’ offset, (or both…)), or you may have a bad linear PSU that’s not filtering ripple noise - that could be bad design or smoothing caps needing replacement (or both…)…
The 5K crap could be breakthrough in one or more component’s poorly-regulated switchmode PSU simply adding noise to signal somewhere, or it could be external in origin and not being filtered by one or more PSU elsewhere, or-or it could be radiated from a source near (but not attached to) one or more hifi component, including cabling…
And those are just the obvious ones. Fun, isn’t it…?
If you have scope to move assorted boxes further apart, plus ensure cables are also as spaced as possible and only crossing at near-enough right-angles, plus make cable runs as short and well-screened as possible, then that might improve things significantly without expenditure.
If you need to look at mains filters, try and borrow/home-dem something to try, as different approaches vary in effectiveness depending on the nature of the issues - best results are had with devices that filter each output separately. That’s expensive, but is a rest-of-your life purchase - Puritan ‘Master’ level stuff is excellent and includes a capable DC-blocker. Cheap filters that put your whole system downstream of a single filter can sometimes increase noise coupling from one component to another, so cheaping-out can be ineffective or counter-productive.
If none of the above works-out then try borrowing alternative kit to swap around, see if the noise follows any one particular box…
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Haven’t followed the whole thread but I use a Crown amp on mid bass duty that has 50Hz hum.
Temporarily lifting the mains earth under test conditions would stop it but that is no solution for me - it was not that intrusive enou even though 110dB / W efficient horns.
Getting it much further away from Najda DSP unit solved the issue completely.
None of my other amps had this problem.
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In hindsight I should not have replied to my old thread to confuse matters 