Every time I study an LP cover I seem to find something that stirs up a question.

Through a screw up of my own ,   I recently got a second copy of the Readers Digest box set  Joyous Music of Christmas Time,   the US release version with the Blue Cover with the Gold Cherub  1963,   there is also a Canadian version which I thought I was getting with the same music but different cover 4 cartoon type singers around a lamppost.

Anyway   the one I have  is an RCA   release  with the Readers Digest ID of RD 22K   for the set.
The new one I got is RD 45M,  other than a difference in the style of the box ,  they are the same music except for one thing.

My original set says on the cover   RCA Dynagroove,   while this newer acquisition  says   New Cyclophonic Miracle Sound Recording.

So What is the difference in the recording technique.  I have read up on Dynagroove on the internet , but the Cyclophonic has me mystified.  I have yet to do an ear to ear listen to see if I can hear a difference,  my gut tells me that due to  the vagueries of long term wear on preowned LPs  I will never be sure.