Ha!! that would be good! but no, more like the sort of thing used on test equipment and specifically for usage—and evaluation of— Fully differential Amplifiers (aka FDAs.) instrumentation amplifiers, and ADCs. there are many different types, if you care to look.
One per phase.
Remember, this is for connection to/from prototypes and evaluation of my own PCBs. not just THD at 1khz. An example, tuning out IMD humps in ESS DACs, or for tuning the networks in wide bandwidth amplifiers. very low noise, very low output impedance power supplies. etc. the sort of thing that could be affected by slightly different, or inconsistent termination between different times connecting the DUT. Each of my boards will be built to connect to it, just like so. with a consistent mounting pitch/standard.
Professional enough for engineers?
Dont really need to satisfy connection to commercial amplifiers and anyway I would knock up an adapter cable if the need arose. After testing is complete, XLR, or whatever desired connector will be added. I could also knock up a very small PCB with a PCB mount XLR, to simulate the finished design.
Also, not all approaches to notches are as simple and cheap as an OPA1612 and a handful of caps/resistors.
Samuel Groner's Passive Notch using many parallel, matched MELF and many parallel thin film caps, dont come cheap. Obviously it needs to be interfaced to an amplifier for gain. you could argue its not necessary, but hey, no harm in over building in instruments IMO and we have the parts already.
Anyway mate, dont take me the wrong way re your design, its just doesnt meet my specific need. I cant stand mini jacks, its a pet hate. I wish they would go away in general
. we can do better. i'm definitely opinionated about it, it's not personal. I particularly like your software from what ive seen, too. well done. If you do a great job on that part with your system as well, I may look past the mini jacks (or replace them ... lol). Sounds like it'll be a great tool for people and we might even get one eventually for secondary, for portable stuff and just because I have a problem with buying electronics.
OK, I think that's enough on this tangent. I'll update the thread and post my own once i've started building my DIY CIEMs