Very enjoyable and informative read with top notch pics. Great stuff! Do bearings collect much gunk over the years and if so, is there a viable method of flushing them without disassembly?
That's an interesting question..
I have read through the assembly section and noted this hole through which the vaseline used for aiding with bearing-assembly can be
flooded out by means of spraying some different liquid through the hole.
I did not get whether this opportunity of flooding the bearings with any liquid is only during this stage of montage,
or in ready-built state as well, Jamie..?
Second thing that cought my attention was the WD40, the original receipe of which at least seemed to base onto some kind of fish oil.
So, first off, I'm not entirely sure of an oily substance is as capable of solving out a substance like vaseline in the complete way I would wish to have it in this situation,
and third, the WD40 itself, even given it would remove the vaseline entirely, is an oily substance.
I'm no expert in arm-bearings for sure, but I tend to think an entirely clean and dry bearing would float even a tiny bit better than an oily one.
And last, an oily bearing will attract any dust to really stick there.
A situation reminding me of steering cardans without rubber-hose.
Well meaning hobbyist mechanics pack those in fat...sand and all kinds of dirt binds to the fat & those steering cardans usually get destroyed quite quickly, while those left well alone don't have sand 'stuck' to them survive comfortably for a very long time.
..well your arm bearing won't be destroyed or harmed for sure by adding any WD40 even shoud it gather a bit of dust over the coming years..
Still, I would check the specs of the bearing balls in the arm and if they take any harm chemically by brake cleaner.
If no...and my guess is, they won't..I would really flush the bearings with brake cleaner.
(Are they metal balls or ceramics,,,I don't remember..)
Alternatively I'd try or check for Isoprop or similar..
It will remove any remains of vaseline much more efficiently than an oily WD40 will be able to,
and there will be no remains of any chemical substance in the bearings left after that.
I'd try the paper test again then,,,wouldn't be surprised if the reaction was a little better even, then.
Nothing lost as obviously you can add back WD40 any time,
but this time you'd be sure the vaseline is really gone.
I'm not 100% sure if arm bearings are meant to have a little oily film on them or not,
but kindly asking J7 of Audio Origami, I am sure he'd be happy to help out in this question.
I'd be curious for the answer, too btw..
I like the pictures a lot & the thread is a very refreshing breath of vintage air to the 'is DAC X better than DAC Y' topics..
P.S. Me, I'd risk a short shot of Isoprop and immediately after a good blow from a 300ml bottle of compressed air you can get in any electronics shop for a few bucks...that should do with a sure and proper cleaning.
If my memory serves me correctly, my Ekos I reacted to a square cut-out of paper the size of a typical math notebook (5mmx5mm)
after it returned from Audio Origami for a bearing check, fine-justage and new inner wire,
in vertical movement w/o any tracking force and skate applied.
And I have little doubt the Zeta doesn't have to worry about an Ekos I too much..
edit: I just consulted the Wikipedia about WD40, and it says that WD40 contains...Vaseline, so flushing out vaseline with a product that contains vaseline itself will probably no leave you with a vaseline-free bearing.
I tend to think there is a little potential of progress in the bearing area still, perhaps.