rlw6534
Headphoneus Supremus
Fantastic, thank you very much!!
By the way @rlw6534 , it seems that this exact model isn't sold any more, not easily, it's sold out almost everywhere. I looked at a bunch of sites. So, if not available I'll get something similar.
Oops, sorry about that, I didn't really look very hard. I think any decent brand should work out fine for you. I have one from Hiby that I like as well.
https://store.hiby.com/products/balance-4-4mm-male-to-2-5mm-female-adapter
Your M3x and Etys should be an excellent combination, especially in the bang-for-the-buck area...