Neutrik NC3FXS 3-pole Female XLR Connector with On-Off Switch Reviews
Have a microphone without an on-off switch? Sweetwater has exactly what you're looking for! The Neutrik NC3FXS is 3-pin female XLR connector that's meant for use with microphones that do not have built-in switches. It functions noiselessly by short-circuiting contacts 2 and 3. It has a die-cast zinc shell that will stand up to tons of wear and tear. So if you're looking for an XLR connector to use with your non-switchable mic, go with Neutrik.
Highest Rated Reviews
"Not plug and play?"
I've had 3 mic cords with these on them for about 25 years, and they perform flawlessly. The ONLY issue I've had is operator error, where someone doesn't know to turn them on and is blaming the soundman (fix with a different cable or gaffer tape).
As for the need to solder them, yes...you do have to do that. It replaces the female jack on the cable. If you did an adapter as you describe, it would make for a really long mic. This is pretty elegant and surprisingly durable.
Only reason I found the "not plug and play" review was that I came to Sweetwater to see if I could order some more after a quarter century. And here they are!
Is not plug and play
You have to solder the end to a cable, apparently. It doesn't say that I'm the description, so I assumed this would have an XLR male and female end with a switch in the middle. If you don't have the tools, knowledge, or time to do that, it's useless.