This is where record cutters raise questions about cutting, and trade wisdom and experiment results. We love Scully, Neumann, Presto, & Rek-O-Kut lathes and Wilcox-Gay Recordios (among others). We are excited by the various modern pro and semi-pro systems, too, in production and development. We use strange, extinct disc-based dictation machines. And other stuff, too.
Just picked up one of these - So far I know it's from 1932 it's described as part of a sound film recording machine here: https://www.radiomuseum.org/r/neumann_r21r_2.html and it has studio 2 written on the box. Has anyone got any other info on this? I note that there's a telefunken branded R12a as well and it's likely to have been on an R21 lathe at some point in its life.
Any spec sheets or other info (particularly impedance) would be great - anyone used one?