Here is Head-fi thread

https://theheadphonelist.com/tahsin-sevgel-audio-devices-m6-lightning-in-a-bottle/
(first, detailed review with full of information)

https://theheadphonelist.com/review-tahsin-sevgel-audio-m3-plenum/

https://www.head-fi.org/showcase/tahsin-sevgel-audio-devices-m3-plenum-ciems.27730/

First Full Package Review from Nick Smith at Soundlymusical.com

Impressions of Daniel Lesmana from The Headphone List, Deezel177 from head-fi

Impressions of JWilliamHurst from head-fi

Impressions of Kerouac from head-fi