I bought a multimeter. What now?

Schwarzenyaeger

Formerly "Dog-In-Door"
I want to know where the + and the - are on my jack plug.
I was told I could plug a cable into the plug and then test with the meter somehow.
 
On an unbalanced 1/4" phone plug the tip is the +/hot and the sleeve is the shield/screen. On a balanced 1/4" phone plug the tip and sleeve are the same and the ring is the -/cold. On a stereo 1/4" connector tip is left, ring is right and sleeve is the shared ground.

XLR is normally wired pin 1 shield, pin 2 hot, pin 3 cold but there was a time when hot and cold were sometimes wired the other way around.

By the way "jack" means 1/4" phone plug in England and the more recent colonies but "jack" is a generic term for the female connector of almost any variety of connector in America. For example "phone jack" is what we call RJ-11 telephone sockets. If you use jack to mean 1/4" connectors, male and female, you can run into some confusion when talking to Americans.
 
Google "how to use a multimeter"...

Time to learn some basic electricity concepts.

Doesn't help you to tell you "A, then B, then C" if you don't understand what you're doing.
 
... that would depend entirely on what you want to measure.

Your question is a bit like saying " I've just bought a pen. What picture should I draw?"
 
Just like to clear up some inter-continental terminology!

"Jack" over here means the female, socket part although it is often sloppily used to mean a plug. For a complete explanation "guitar" type 1/4" plug might be referred to as "6.35mm" and the 1/8" plug as "3.5"mm. We also have a "Bantam" plug of about 5mm? (don't have one handy).

We do not use the term "phone" for jacks at all in general. If you have a telephone lead here it will have a "BT" plug on it to go into the wall socket.

Hi Fi amp inputs are "Phono" plugs and I usually call them "RCA Phonos" to be clear in forums.

In the network industry the female connector is also called a jack be it RJ45, RJ11 or the weird MMJ.

Re the digital meter: You will be able to read the audio signals from AIs, mixers etc but be advised, they all* fall off very badly with frequency and even as low as 1kHz can be 6dB down on a 50Hz reading.

*Unless they are quite expensive >$200 such as my trusty Fluke 83.

Dave.
 
... that would depend entirely on what you want to measure.

Your question is a bit like saying " I've just bought a pen. What picture should I draw?"

I've got a hot and cold that need to be connected to a guitar jack input for a DI box. I was told that using the multimeter I could identify which of the five pins on the jack needs to be connected to the + and which one to the -.
I haven't been able to find very clear instructions on how to do this.
 
5 pins???

At most, three, for a balanced connection, or stereo - but if it's going into a DI box, it's just two - one for tip and one for sleeve.

The test is simple.
Make sure you are on the lowest resistance setting.
Touch the two test probes together - check the meter reads 0 or very close.
with thumb and forefinger, put one probe on the tip of the jack, with it's cover off. It should sit there in the narrower 'dimple' quite happily. The other probe then needs to be touched to each of the connections in turn. When you find one that the meter says is a short - as in 0 Ohms, that is the one connected to the tip of the jack, so it's your hot connection. Then put the probe on the sleeve, not the tip, and repeat the test. As soon as you find one connection that reads 0 Ohms, it is the cold connection. It's very, very simple. The biggest snag is dexterity - keeping the probe connected to the jack with two fingers, while prodding with the other hand.
 
I mean that it has 5 metal prongs sticking out the back of at that all look like they're begging to be soldered.

That sounds understandable. I'll be back with results.
 
Yep, it's probably a switched TRS jack. You only need two of the connections, but you have to make sure that the tip connection you use is not the one that is switched off when the plug is inserted. Ideal would be to plug in an actual balanced TRS>TRS cable and then measure the tip of the cable to the prongs on the jack and then the sleeve, pretty much the same way rob said. You can ignore anything that hits the ring, unless you want to build in some redundancy for safety, in which case youd wire the actual (not switched) ring lug to the same place as the sleeve.
 
Does the attached help?

The hot/tip connection is extreme right. Cold/sleeve is extreme left by the "nut".

The picture is of a PCB mounting type. The switch is on the other side and can be ignored for this application I would think.

Note: If wiring jacks on OUTputs it is worth wiring them as "impedance" balanced, just need an extra resistor but leave us K.I.S.Sir for now!
 

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Just to make sure:

In this case (any case where you're measuring resistance or continuity) it really doesn't matter which multimeter probe goes where. It's going to measure the resistance between the probes, and it will be the same, either way...unless there's a diode involved....

Really, even when measuring voltage or current it's not a huge deal. Like, nothing's going to explode. Most of the time when I'm measuring those things I know the expected polarity (can't be negative in a 9VDC pedal) and all I really need is the number.


Edit - rob said to hold the probe against the things with your fingers, and for what you're doing here that will be fine, but if you were trying to actually measure some resistance with reasonable accuracy, you should not touch the probe or whatever your testing on at least one end. If you're touching both probes, then you're measuring yourself in parallel with whatever you actual want to measure, and that will skew your readings. In this case, though, like I said, you just need to know if it's very close to 0 or not. I suppose it should be obvious that you wouldn't really want to touch the probes at all if you are poking around in a high voltage environment.
 
Hey guys!

I got it to work with the help of one of my university teachers today. We tested it and it sounds f-ing brilliant. Very clear tone.

Thanks for all the input.
 
Did I miss something in the US to UK translation. In the first post he said PLUG, then we suddenly started talking about sockets - I misread it, as he said he wanted to plug a cable into the plug? Plugs are male, sockets are female, at least they are when we talk about jacks - jack plug and socket.
 
Did I miss something in the US to UK translation. In the first post he said PLUG, then we suddenly started talking about sockets - I misread it, as he said he wanted to plug a cable into the plug? Plugs are male, sockets are female, at least they are when we talk about jacks - jack plug and socket.
I don't think so. As I understand it, he's got what I'd call a jack and you appear to be calling a socket that he needs to figure out. He wants to plug a cable (I guess we agree that it's the plug?) in and measure from the "plug" on the other end to the lugs on the back of the jack/socket.
 
Did I miss something in the US to UK translation. In the first post he said PLUG, then we suddenly started talking about sockets - I misread it, as he said he wanted to plug a cable into the plug? Plugs are male, sockets are female, at least they are when we talk about jacks - jack plug and socket.

In the US "jack" generally means the female of any type of connector, in the UK it appears to mean a male or female 1/4" connector. In US jargon a jack plug would be a contradiction. In the US we also call them phone plugs and jacks, but that brings up confusion with RJ-11 connectors which we also call phone plugs and jacks. I just avoid using the terms phone and jack when possible and refer to them as 1/4" plugs and sockets or sometimes TS and TRS when appropriate.
 
Did I miss something in the US to UK translation. In the first post he said PLUG, then we suddenly started talking about sockets - I misread it, as he said he wanted to plug a cable into the plug? Plugs are male, sockets are female, at least they are when we talk about jacks - jack plug and socket.

It makes no difference. The mechanism is just coupling and uncoupling. The important consideration in this application is continuity. Forget the terms...
 
...and just for the record here in the UK the terms used when you want to order any similar parts are "jack socket" and "jack plug".

The female part is the socket and the plug is the male.

What some muso type wants to call them when he rocks up at Maplin or Radio Spares is not important.
 
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