Mesa 4x12 cabinet issues.

  • Thread starter Thread starter Tone Junkie
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Tone Junkie

Tone Junkie

Well-known member
I’ve got a Mesa 4x12 cabinet that has the four hole jacks on it. Two are for 4 ohm stereo. One is for 8 ohm single input only. The fourth don’t recall
Issue is both 4 ohm inputs working. Single 8 isn’t. I took back off and it seems to have never been opened. The Jack has these weird stiff metal wires. All appears to be ok.
Anyone else ever have this issue.
If I replace it with a single input any suggestions on what would fit.

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Dumb question...but are you 101% sure the 8 ohm jack has ever worked since you had it? If it used to work and now does not, you should be able to see something inside, like you were thinking.

I know myself; if I really couldn't find anything loose inside, I would probably assume that I had in the past used one of the 4 ohm jack thinking it was the 8 ohm, causing me to think the 8 ohm jack was wired when it never was.

Edit: A pic of the other side of the jack would be helpful. If not to me, someone else here surely.
 
Thanks. I decided to just order a single input Jack.
 
I think the fourth jack (top right) is if you were running two cabs and sort of daisy chaining them. Do you have a multi-meter so you can measure the resistance tip-to-sleeve of a cable plugged into the various jacks?
 
No. I can get one. How do I check it. You’re talking noob when it comes to wiring.
 
I had the same issue. You need a new mesa 8 ohm input jack. There’s a small white piece of plastic on the end that wears out.
 
I have had this problem with about 5 mesa cabs. Those jacks wear out and begin affecting the cab impedance. The problem is that the sound can cut out and you can run your tube head without a load, possibly causing damage to your head.

To fix it, I just put a mono jack on the 8 ohm input. You have to change 4 wires in order to it. It all depends on how confortable you feel with soldering. You have to disconnect both pairs of white and black cables form their jacks (4 in total, 2 white, 2 black). Solder the left black cable to the right white cable. Solder the left white cable to the positive of the jack. Solder the black right cable to the negative of the jack. Done.

It basically gives you a mono 8 ohm cab as it bypasses the stereo features.

Hope this helps.
 
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