Quad Cortex Not Detecting Guitar Signal

Quad Cortex
1

I connect my guitar to Input 1, the Quad Cortex does not detect the guitar signal. The input meter does not move when I play the strings, and the tuner does not detect any notes either.

So far, I have tried the following:

  • I tried multiple presets.
  • I replaced the battery in my guitar.
  • I checked the instrument cable.
  • When I disconnect the cable from the guitar and touch the tip of the cable with my finger, the Quad Cortex detects the signal and I can hear noise through the speakers.
  • However, when I plug the cable back into the guitar, there is no input signal at all.
  • I also made sure that the Quad Cortex volume is turned up.
  • I have also tried / am planning to try a factory reset.

I also tested the same guitar with another processor, and I could not get a guitar signal there either, although touching the cable tip produced a signal there as well.

Could you please advise me on what I should check next? Is there any specific input, I/O, or diagnostic test you recommend?

2

“I also tested the same guitar with another processor, and I could not get a guitar signal there either, although touching the cable tip produced a signal there as well.”

If you tried with another guitar processor and it still didn’t work, I’d assume you have a bad cable or something similar. Have you tried another guitar and or cable?

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3

Sounds like the problem is with your guitar. It happens. Check the wiring if you’re confident enough, or take it in to a repair shop to see if they can diagnose the problem.

In the meantime, try a second guitar with your QC to make sure it’s OK.

4

DC is right, your testing indicates a guitar problem, not a problem with your QC.

5

Seems like you solved it by testing with another modeler that didn’t get signal from the guitar either. Your guitar wiring needs to be fixed

6

I don’t have another guitar or cable. I’m planning to take the new Quad Cortex—and my guitar—to the music store tomorrow. I hope the problem lies with the Quad Cortex, because I bought the guitar in Türkiye. If the issue is with the guitar itself, I have no idea how to fix it or how much it would cost.

7

If the problem was with the QC or your cord (unless it’s an intermittent problem) you wouldn’t hear hum/buzz when you touch the plug at the guitar end. If you have no signal, regardless of the position of your guitar’s controls, it’s likely something simple, downstream from the guitar’s PU switch, like a broken wire or bad solder joint. Sorry for your agonizing, Agonizing.

8

You validated it didn’t work with another processor so you eliminated the QC from your issue.

You did indicate you don’t have another guitar to test with but do you have another guitar cable to test with? I saw that you tested your cable but have you tried with another cable just to eliminate that as the source?

9

If you have a few basic tools (screwdrivers, mainly) we could probably walk you thru diagnosing the guitar. There are also MANY YouTube videos that might prove useful

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10

It’s probably a very simple and cheap soldering fix. A guitar tech or music shop near you could fix the guitar, which seems to have an electronics issue

11

Thanks everyone for the help. I took the guitar to Music Store and they fixed the issue for €30. I have an active-pickup guitar, and it turned out the problem was related to the wiring/cable connection inside the guitar. Everything is working properly now. @DiffractionCircuit @MP_Mod

4 Likes
12

Glad you got it sorted out. Enjoy your Quad Cortex.

2 Likes
13

Thanks for the update @Agonizing and glad you got it all sorted! Enjoy that QC!

1 Like