However, output jacks for an active system have three lugs. The output jacks on passive guitars are pretty simple-they have one lug for the primary lead and one for the ground. Simply touch the shaft of both plugs with the test leads and listen for a solid tone. You should also test the ground on the cable. However, if the test tone is intermittent you’ll know there’s a problem. If after shaking the cable and testing it several more times you continue to get a solid tone, you can assume the cable is good. But don’t stop there: Move the cable around a little to see if it has a short, and test it again. If you hear a solid tone, you have a connection. Set your multimeter to test continuity, then touch the tip of both cable plugs with the test leads ( Photo 5). The good news is, it’s quick and easy to test your cable with a multimeter. Is the amp blown? Does the guitar have a loose output jack? Chances are it’s the guitar cable-that’s the place to start troubleshooting. Have you ever arrived at a gig or rehearsal only to find you have no signal? The worst part is not knowing where the problem lies. As you map a switch’s connections, draw a diagram so you’ll have something to refer to in the future. By carefully working through each switch position, you’ll be able to locate its corresponding input lug. Then touch each of the other lugs with the other test lead and listen for the tone. Touch the last lug on the switch-this will be the output lug-with one of the test leads from the multimeter. It’s a similar process for a Strat-style 5-way blade switch ( Photo 4). If there’s no tone in that position, the switch is off. If you hear a tone, then you know the switch is on in that position. On a 3-way toggle switch, for example, touch either one of the side lugs with one of the test leads from the multimeter, then touch the middle lug-that’s typically the output-with the other test lead ( Photo 3). This setting will produce an audible tone to let you know when a circuit is closed. Simply set your multimeter to the continuity setting, which is marked with a speaker or soundwave icon. An easy way to save time when tackling a wiring project is to use your multimeter to map out the switch. If you don’t have a diagram to follow, wiring a new switch can be frustrating. Single-coil pickups can range from 6k (vintage) up to 16k (high-output). The 16.25k reading we see in Photo 2 indicates this is a hot humbucker. For example, humbuckers typically measure at around 8k ohms for a vintage-style pickup to as much as 25k for a high-output pickup. Have you ever arrived at a gig or rehearsal only to find you have no signal?Ī multimeter can tell you a lot about a pickup before you wire it up. If the impedance measurement you take is significantly lower than the manufacturer’s rating, then you know there’s something wrong with the pickup. To make sense of a particular model pickup’s reading, check with the manufacturer for its exact impedance. This should give you an accurate impedance measurement. Touch the multimeter’s black test lead to the green and bare ground wires on the pickup. Touch the red test lead from the multimeter to the black wire-the pickup’s primary lead. For example, before you try to measure the impedance on a Seymour Duncan humbucker ( Photo 2), make sure that the red and white leads are connected to each other and isolated from any other connection, and the green and bare leads are also connected to each other.
If you’re testing a humbucker with four conductors, make sure that the wires are properly attached to each other. Set the multimeter to the ohm setting and touch its red test lead to the pickup’s primary lead (hot) and touch the black test lead to the pickup’s ground wire. If I’d brought a multimeter with me, I could have tested the pickup on the spot and saved some money. I learned the importance of this the hard way when I bought a used pickup at a guitar show, only to discover it didn’t work when I got it home. On many occasions I’ve used a multimeter before buying a used pickup. Identifying the lugs on a TRS output jack.Testing pickups (impedance and functionality).Let’s explore five ways to use a multimeter: I still use the one I bought at Radio Shack 23 years ago, and such luthier supply companies as Allparts and Stewart-MacDonald have excellent multimeters designed for working on a guitar, priced from $25 to $35. Best of all, you don’t need to spend a fortune to get a good multimeter. We use them in the shop for testing pickups, output jacks, switches, and batteries, and you can also use them for testing cables and wiring harnesses. A digital multimeter ( Photo 1) is the perfect tool for testing many components on a guitar or bass.
0 kommentar(er)
