We've been using Canon inkjet printers for quite awhile (had two). Our current one is a TR8500 something or other IIRC. I buy the ink off of Amazon (EZ Ink store there) and it has worked fine. I had used Epson prior to that but got tired of their print heads clogging and bricking the printer. Ink is $25 for a full load for our model (currently on sale for $16).
EDIT: Our is a TR8520. Best Buy has a similar TR8620 now, here.
Ordering from places like JLCPCB is pretty economical. I hope you did 2oz copper and at least 1.6mm PCB thickness? 10 boards for ~$90 shipped (this for the v1.2 full board).
Nelson Pass apparently mentioned it at Burning Amp last weekend. I wasn't there so don't know what he said about it, but the insinuation was that he was favorably impressed by it.
I know these aren't Stax, but have any of you tried Audeze CRBN2 in lieu of the 007s? Bob Katz seems quite enamored with them using one of Birgir's Carbons as the amp. Kinda expensive, but not sure what 007s are running these days either.
https://positive-feedback.com/reviews/hardware-reviews/imersiv-d1-dac/