Some people said their Truthear Hola had clearly uncured resin or something, there was like some picture of it. And I forgot if it was Delta Fyre or Hi-Fri Audio (those people on Facebook that do teardowns/dissection/etc. of IEMs), but the Kiwi Ears Cadenza and is it Tin HiFi C3 or something also had that resin problem (there was liquid leaking just behind the seams).

Here's a recent post, apparently somebody with the new CCA CRA: https://www.reddit.com/r/headphones/comments/11q5wa6/i_stuffed_some_biological_filters_into_my_cca_cra/

Click this sentence for pictures of the new CCA CRA from somebody on Head-Fi/etc.

Basically they changed the box and so on, check the Head-Fi thread for the CCA IEMs. So many stealth revisions or changes even when it comes to $500+ IEMs, lol.

This stealth revision infamously happened with the QKZ VK4 and other budget IEMs.

See zpolt's video on the QKZ VK4, note apparently according to other people or regular commenters he doesn't even have all of the VK4 stealth revisions, lol: https://www.youtube.com/watch?v=I9TwlD8scIs

There's also just the unit variances. And like the quality assurances, control, etc.

Here's oratory1990's graph about the deviations with the Sennheiser HD 650: https://www.reddit.com/r/headphones/comments/11mhu3f/hd_6_series_fr_comparison/jbnt9fk/?context=10000

Try to buy HiFiMan from Amazon or a place with good warranty/returns as HiFiMan is infamous for quality control issues.

Here's another recent HiFiMan quality control post, like it's for an open box unit, but that happens with brand new headphones too, lol: https://www.reddit.com/r/headphones/comments/11ex8iw/hifiman_wants_me_to_100_to_send_my_defective_upon/

See here for a bit more info on HiFiMan quality control problems: https://www.reddit.com/r/HeadphoneAdvice/comments/zicl2e/most_common_defects_for_the_he400se/izrcf3p/

Back to the actual Truthear HOLA or IEMs. Try cleaning the filters/nozzle, it might fix the channel imbalance issue. Try also switching cables to see if it solves the problem.

Though yes, people report drivers dying for no reason with the Moondrop Chu, Aria, etc. The prevalence could be due to the amount of volume that Moondrop/etc. sell, or yes just factory/design choices/etc. issues from the start.

Btw, some people damage their IEMs by dropping them all the time or getting the cables tangled/yanked/etc. Make sure to roadie wrap your IEM cables, https://www.youtube.com/watch?v=_fsvANAT3yg, and put them inside a case with hard covers in order to protect them when you're not using the IEMs anymore.

For long term use you might encounter condensation issues with IEMs, try to take breaks every 30 minutes or 1 hour, and wipe the ear tips and IEMs with a clean paper towel or microfiber cloth.

People with the Moondrop Aria have posted pictures about the paint bubbling/peeling/etc. even with the newer Aria Snow Edition. Some recent pictures of the Aria: https://www.reddit.com/r/headphones/comments/121k4gz/scraped_sanded_my_year_old_moondrop_aria/ and https://www.reddit.com/r/headphones/comments/11imkcv/1_year_of_using_my_first_iems_the_moondrop_arias/ and https://www.reddit.com/r/headphones/comments/10hn5z6/moondrop_aria_se_cover_is_coming_off/

Click this sentence for how to delay or prevent earwax/moisture/etc. from clogging the IEM nozzles with AZLA Sedna MAX Standard ear tips, et cetera.

Essentially for the future, just use a clean paper towel or microfiber cloth and wipe your ear tips and IEMs after each use. That should prevent/delay the clogging/condensation/etc. issues. It's just a problem with certain IEMs, more so the ones with metal outer shell designs. And if you live in a humid area or produce a lot of body heat.

[Click this sentence for how to maybe fix earwax clogging the filters/nozzles.] (https://www.reddit.com/r/headphones/comments/yzkk5e/how_to_remove_ear_wax_from_iem_without_damaging_it/ix13bpo/)

Basically use 90+% isopropyl alcohol but make sure the IEM nozzle is facing down as you don't want alcohol to get inside and possibly damage the coating/drivers/etc. behind the nozzle/filters/etc. And then wait several minutes for it to dry, better to wait an hour or so for near certainty that everything is dry.

So ya, you can delay those earwax issues if you use AZLA SednaEarfit MAX Standard (MAX Standard has an integrated wax guard), Spinfits, etc. Like Spinfits have this inner lip for the rotation gimmick and that sometimes help with slowing down the earwax from dripping directly down on the nozzle/filter.

Click this sentence for more info on the importance of ear tips sizing, dimensions, et cetera.

Click this sentence for comfort and everything with ear tips.