Is usb reclocking necessary?

You all have obviously been at this for awhile. I’ve been out of it for 40 years and just getting back into it. I don’t know what a 10 MHz hookup is! I did add a Furman power conditioner/surge protector and it made a slight sonic improvement. I have a carpeted floor and putting the floor standing speakers (Volti Razz) on thick pavers improved the bass too. A good step might be to add a good turntable to audibly judge the digital reproduction against. That may tell me where to stop tweaking. Thank you all for your input!!

You know, looking at your question again. The answer is clearly no, the Ayre is an excellent DAC so it is not necessary. You will likely enjoy a good turntable. While my Ayre is a good DAC, it does not approach a good analog end. There are so many great turntables out there… but don’t forget a great Phonostage is required to get the most out of a good turntable. I am just listening to an analog recording and marveling at its wonderful sound. 

You don't get clock anomalies with analogue.
All fixes for clock error and dither are cludges.

@kijanki The QB-9 USB interface is galvanically isolated from the DAC section so ground pollution shouldn't be a concern.
Seriously, Ayre put a lot of thought into the implementation.
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Yeah, you don't get clock anomalies with analog - but you *do* get measurable wow and flutter and surface noise with a turntable.

I will point out that the clock anomalies ARE analog :-)
.. and have direct analog implications.
I will also add something i ought to have said earlier but neglected to:  proper clocking inside the DAC (either between the USB interface and the internal oversampling or as the actual system clock itself) is vastly better than an external box.  An external box can only reduce the incoming jitter.  Keep in mind that, in an idea world,that jitter ought not matter since the DAC syncs on that, and generally either terminates or enacts a PLL to reduce jitter and then  typically clocks things in an out of whatever register arrangement exists.  But clearly, it does matter.
Since the only thing that matters is the timing coming into/out of (they better match!) your DAC chip or resistors, the latest possible point to execute a proper clock is the best.  his makes any box you can plug in less than ideal. Unclear what the outcome is if it is better than source but worse than internal.
That would be an interesting experiential some day.