Cartridge break in

5-6 weeks of play about 40 hours can make some difference. I couldn't wait and recorded an album onto my Nakamichi Dragon right after I got my new Benz S cartridge. A month later I rerecorded it over just because I read about cartridge break in and wanted my recording to be the best. Well I accidently failed to record over first 15 seconds and when I played tape back there was a noticeable difference in the bass from the first 15 seconds. It had tightened up. The song started with bass drums so I didn't have any high frequencies to compare. I hadn't changed the bias or record settings because there had been no other tapes recorded. The only other thing that might could matter is the warm up time on the Dragon. I don't know if it was the same on the 2 recordings. Some Audiogoners could repeat this chance experiment and post their results. The song was Helena Beat by Foster the People.

If your MC cartridge is used and you've just had it re-tipped would it require break-in again?

That would depend on whether the rebuilder replaced the
compliance(the material in which the cantilever is mounted),
or not.

Thanks for the feedback.
I'm pissed with myself because the Aries/Zephyr combo was "dialed in." I was really pleased with the sound: violins had a woody mellowness without a trace of harshness; piano reproduction inched closer to how a piano sounds.
But I wasn't satisfied; more is better; a $3K cartridge must be better than a $1K cartridge.
Oh la…
In fairness to the Kleos, it is better Hi-Fi. It seems clearer and more defined but the result, for me, is a better look into how the recordings were made and not into the enjoyment of music.
I fell like the traitorous Cypher in the Matrix. I don't care if my system is not accurate; I want to be fooled by it.

Unfortunately going up the hifi ladder can be difficult as one upgrade will bring out the next weakness in your system.

The Lyra Kleos is not a bright cartridge, it is very smooth and transparent. Perhaps a little hifi sounding compared to a dynavector and perhaps the SS.
Your musical surroundings phono now has to use an additional gain stage for the mc signal. The ms phono is now your weakness as it can sound mechanical and lean.

You replace the ms phono with something better and the Kleos will start singing.

Tuff decision, as IMO if you want to get the most out of the Kleos you need a better phono stage.