Predecessor of the LTZ1000 (Patreon)

Not quite as compact, but a few more independent voltage references AND a lot of unpopulated spots in this beast. It's basically a precision oven, that tries to stay at 30 +/-0.1 °C to keep the weston cells happy. It needs a proper restoration tho, I've already found 1 electrolytic cap from 1986 😅