1/4" and 1/8" audio plugs and jacks - Tutorial
If you are using pro gear, you may never have to deal with this, but many folks are working with camcorders that only have 1/8" audio input jacks. Connecting gear properly can be confusing. This may help.
Plugs and how many conductors they have is just plumbing. How the plugs are *wired is what counts. You can't tell how a plug or adapter is wired just by looking at it.
The black lines are insulators. If your plug has one black line, it has two conductors; a tip and a sleeve. Normally you'll see this referred to as TS (tip sleeve). For audio, this is usually an unbalanced mono connection.
Two black lines means two insulators and three conductors; a tip, a ring and a sleeve. Normally you'll see this as TRS. *Most of the time this is a balanced mono audio plug or an unbalanced stereo plug. Particularly with 1/8" plugs and jacks, TS and TRS are seldom compatible.
However, it can also be a *specially wired TRS mono plug, as is the case with Rode's Video Mic. The Rode Video Mic is a mono mic designed to be plugged into a stereo camcorder input. The tip and ring are wired together so that the mono signal from the mic reaches both left and right channels in the camcorder. The sleeve is the ground.
I've seen 1/4" TRS jacks wired to be able to accept mono TS and TRS plugs, but I have never seen 1/4" jacks wired to accept mono and stereo plugs. I don't recall seeing this with the 1/8" jacks you see on camcorders, but that doesn't mean that they don't exist.
You may have had some success with inserting a plug part of the way into a jack. Some of the Mackie mixers have that as a solution for taking unbalanced, mono audio out of the insert jacks. The circuit is designed for that, so it's OK. If not, the connection is shakey at best and you're liable to get clicks, pops, buzzes and hums.
Pros don't like 1/8" plugs and jacks because the connection is not as secure as with an XLR or TA connector and because the actual area of contact (metal to metal) is a lot smaller in a 1/8" connector. Get a little dirt in the wrong place and you lose the connection or it gets funky.
Want better production audio?: Ty Ford's Audio Bootcamp Field Guide