Preamp for 500 Series

The Auteur MkII 500 is one of the most “bang for your buck” 500-series preamps in existence! You get all of the sound of the rack version, but with the addition of a Hi-Z input! It features an ultra-fast input stage that captures lots of detail and nuance, and a signal path transformer that adds some “beef” on the way out. Once you hear the Auteur MkII 500, you’ll want to load your 500 rack full of ‘em!

https://blacklionaudio.com/product/auteur-mkii-500-mic-pre/

No info about availability.