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Post by kledbet on Jul 13, 2006 10:01:02 GMT -7
Hey Guys, my reverb models Maz 18 with 2x10's has a hum. It sounds like a little 60 cycle ground hum. I hear it even if all the knobs on the amp are turned off. Could this be loose tube pins? Anyway I figure you experieced Z'ers will know.
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Post by billyguitar on Jul 13, 2006 10:34:00 GMT -7
I don't think it would be loose pins. First try unplugging the guitar cord. If it stops then, it's probably something like pedals that are humming.
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Post by kledbet on Jul 13, 2006 10:40:26 GMT -7
I unplugged the guitar and it hums without anything hooked up, as I mentioned even with all the knobs turned totally counter clockwise.
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Post by billyguitar on Jul 13, 2006 10:58:48 GMT -7
All you can do now is start replacing tubes. A guy needs backups anyway. If you have spares already just replace them one at a time and see if it goes away.
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Post by kledbet on Jul 13, 2006 11:32:15 GMT -7
I think you may be right. I called Fat Sound and they said it might be mismatched power tubes. I thought these were matched, but I'll start over and see what happens. Just as a side note this is only my 2nd model of Z amp. Somehow me and the Route 66 could not seem to find common ground. The Maz 18 does everything I want and seems to fit me much better. It is really an amazingly versitle amp with rich warm tone.
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Post by Strato on Jul 13, 2006 17:32:36 GMT -7
I had this problem while on stage one day. Turns out, i was plugged into an isolated outlet, but it was in the same socket as some dimmer packs for stage lighting. I ran an extension cord to a floor outlet and it fixed the problem. Good luck!
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Post by squishycat on Jul 15, 2006 13:24:13 GMT -7
I am also getting this. Whenever I turn up the reverb, the hum turns up, too.
Here's what I've done so far...
1. unplugged anything from the front (guitars, etc.) 2. Changed electrical sources (including adding power conditioners and not) 3. Changed EVERY tube to fresh w/ matching EL84s 4. Checked internal connections to the reverb tank 5. Rerouted, as much as possible, the lines to the reverb tank
Nothing seems to work. The hum is actually so bad as to make the reverb unusable.
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Post by billyguitar on Jul 15, 2006 15:27:49 GMT -7
Unplug the reverb cables from the bottom of the amp chassis, see what happens. No change? Sorry, tech time? You replaced the preamp tubes too? I think V3 and V4 are reverb drive and recovery. It has to be something to do with the cables to the reverb, connections to the chassis, or the tank itself. Usually the reverb just quits when it goes bad.
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Post by squishycat on Jul 19, 2006 20:02:49 GMT -7
I think I've found the problem.
The transformers are inducing the hum. I have the head version, so space is a little cramped. I can adjust the alignment of the unit with the transformers to minimize the hum, but it seems there's no way to fully get rid of the hum other than moving the reverb unit outside the head.
Oh, well.
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Post by kledbet on Jul 19, 2006 21:52:01 GMT -7
Hey guys many thanks for the help. I have the amp with a good tech and he is going through it and should have it readys on Monday of Tuesday next week. I'll let you know the outcome. Even with the slight hum the amp sounds great. A really great amp for just about everything I would ever want to do.
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