So I can report that I have had an interesting resolution to the RFI/EMI noise issues that my R6 Pro has been plagued with. I have so far used earphones with 2.5mm balanced plug, hence needed an adaptor for the 4.4mm R6 Pro connection. The adapter I have used from day one and until now was supplied by the HK dealer I ordered the Pro from a few weeks ago:
So all along that past few weeks I have used the above Hiby adapter as the only way to connect my earphones to the Pro. For form factor reasons, I had also separately ordered from the Musictek an angled adapter (the Cayin shaped one), which I only received yesterday:
Since I have switched to the newer adapter, its been like night and day difference: the EMI and RFI noises have almost entirely gone, even with the JH Roxanne which have exhibited much of these noises. Of all the reasons and culprits I had suspected, I must say that the last thing I thought as the enabler for these EMI noises, was the adapter.
The only noise I get now is if I bring my iPhone to within an inch of the Pro (the usual phone proximity buzzing noise) and this noise only lasts for a brief one or two seconds (just as I bring the phone to the proximity of the Pro) and then goes away - even if I leave the phone next to the Pro. I gather this "one off" noise is normal (as confirmed by a previous poster here). No other noises can be heard .. no crackling, no bopping, no hissing, no frequent buzzing (all these I used to hear almost constantly).
All I would say is if you are using adapter, do check if this is the root cause for your EMI noises. I am not exactly sure why the Hiby adapter was causing these noises, could it be because the interconnecting adapter wire was acting like an antenna absorbing and then transmitting interference etc?
I know the above my not perhaps solve everyone EMI noises issues, but I can now count myself as one of those whose device is fine, it was the adapter all along. I hope this can help a few Pro owners eradicate their noise issues too.
In terms of the adapter I am now using, its not (strictly speaking) the Cayin one, as it doesn't have the Cayin logo. But from everything I have checked and seen, its
exactly the same adapter as the
official Cayin one (which is anycase made by that same third party manufacturer, as Cayin don't make adapters), except it
doesn't have the Cayin logo on top, hence Musictek sell it for USD 25 (and the official Cayin one is priced at USD 50).
I would very much be interested in hearing of others experiences if they switch adapters they are using.
p.s. my device production date stamp is 22 January 2019, international version.
