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Picture of DIY Guitar Cable Tester
Hello Wozn here from the band Rooftop Ridicule. Today I'm going to help you make a quick simple cable tester that's already saved me much time and heartache. You don't realize until you have one how useful it is to confirm in a second whether a cable is trustworthy or not, not to mention handy. You can't always be sure with an amp and a guitar when input jacks are so often the culprit, you may think you have several bad cables, and sometimes you're right. This way you can confirm or rule-out the cable for sure.

Step 1: Gather Parts

you need:

two stereo 1/4" jacks
three leds (recommend: 1 red 1 green 1 yellow 'cause that's rasta)
three 330ohm resistors
a little speaker, from say a clock radio or something, this is OPTIONAL
9v battery clip
9v battery holder
9v battery
a box

thats it my friends!

Can mono jacks be used?
johnrcoburn7 years ago
I added a photo showing what I have done. When I plug in guitar cables and click on, in one direction the light comes up green. None of the other lights work even with bad guitar cables. Now when the light does turn up green the cables are in working condition which i like green means go. but something is obviously wrong here. I spent all the money for this and soldering iron. Please help.

link to picture incase it didn't show up:
xenocoder8 years ago
Thanks, really cool project and useful. One thing you may want to add to the "parts" list is the SPDT switch? I may have missed it but I don't think it's on the list now.

Again, thanks for the posting!
macman8088 years ago
can i use 1k resistors instead?
wozlaser (author)  macman8088 years ago
not with 9v
What if your cable testers inputs break?
Very easy and useful project. I did it almost the same way, but also added two XLR jacks (male and female), attached to the 1/4". With this I can teste 1/4" to 1/4" cables (both mono and stereo), XLR to 1/4", 1/4" to XLR and XLR to XLR.
Thanks a lot
wozlaser (author)  ze.gmonteiro9 years ago
that's great! do you have a link to a good pinout of an 1/4" to XLR cable so when I add xlr, I wire mine up in a way that makes sense?
No, I simply connected the 1/4"  (stereo plug) and the XLR at the same time. (n° 1 of 1/4" with n° of XLR ...)
Very simple idea.  If you make it smaller, you could probably sell it and make lots of money.