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Post by kelley on Aug 11, 2006 11:16:47 GMT -7
Hello all, I have had this maz 18 nr head for about 2 months now. I bought it used locally. it was a few years old, but had great care.
Anyways, I was playin the amp the other night (for maybe 20 minutes) and all of a sudden no sound. The amp lights up and there is a normal sounding hum, but no sound. All the tubes light up. I replaced the 1/2 amp fuse (even thought it looked fine) and no change.
Has any one had a problem like this?
Any help would be very much appreciated!
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Post by John on Aug 11, 2006 12:06:38 GMT -7
Right off the bat, I'd change your power tubes. Just because they light up, doesn't mean they work correctly. Also, with this kind of amp, keep some spare power tubes handy. Especially at a gig.
These amps really chew up power tubes. They (the tubes) will not last years like on other amps.
Remember to get 'matched sets'.
If that doesn't get it, I'd look at the preamp tubes...but this is far second.
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Post by billyguitar on Aug 11, 2006 12:51:23 GMT -7
I would unplug the guitar cord in front. Turn it up and treble up, does it hiss? If not it's the amp or a tube. The rectifier tube is kind of hidden so be sure it's glowing too. If the amp does hiss check your guitar cord or effects, something might be stopping the signal from getting to the amp.
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Post by kelley on Aug 11, 2006 14:16:40 GMT -7
Thanks for the reply's! The amp is only used in my studio. I changed the pre amp tubes and no change. I will replace all the tubes again this weekend, but I am doubtful that is the problem. I did unplug all of my pedals immediately and tried differant cables and guitars with no change. There is no hiss when the volume and treble levels are up. I will try all new tubes this weekend and let you know what i find. If the tubes do not rectify the problem, what would be some other probable failures?
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Post by billyguitar on Aug 11, 2006 14:48:46 GMT -7
Don't forget the rectifier tube. It's not likely but it wouldn't hurt to try another speaker. Anything will work to try it out. If you have no speaker try unplug the speaker cord and touch a 9 volt briefly to the plug. One terminal on the tip and the other terminal touching the sleeve on the other side of the black separator ring. If no pop it may be blown. Unlikely but possible. If power tubes and rectifier aren't it then it's off to the tech.
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Post by kelley on Aug 11, 2006 15:19:16 GMT -7
I have 2x12 z best cabinet. I tried another head that I have with that cabinet and worked fine. I also used another speaker cabinet with the maz and no differance. I will be replacing all of the tubes (including the rectifier)
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Post by billyguitar on Aug 11, 2006 16:03:25 GMT -7
Probably a tube. Cross your fingers.
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Post by guitargeorge on Aug 12, 2006 15:04:34 GMT -7
Does it have an effects loop? An effects loop is the weakest point in an ampwith an effects loop because your signal must pass through a small spring switch on the send (or return, I'm not sure). If that contact becomes corroded the amp will either cut out or it will fade in an out, If it has a loop plug a jumper between the send and return and see what happens. If it works take some de-oxit and spray the jacks. I had amp tech that told me this was about 90% of the trouble with Marshalls that would come into his shop.
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Post by kelley on Aug 12, 2006 16:18:41 GMT -7
I put a brand new set of tubes in today and when I turned it on, the power light came on for a second and then faded out. Checked the 2 amp fuse, and sure enought, if blew. Any one have an idea why that would have happened. Does it have an effects loop? An effects loop is the weakest point in an ampwith an effects loop because your signal must pass through a small spring switch on the send (or return, I'm not sure). If that contact becomes corroded the amp will either cut out or it will fade in an out, If it has a loop plug a jumper between the send and return and see what happens. If it works take some de-oxit and spray the jacks. I had amp tech that told me this was about 90% of the trouble with Marshalls that would come into his shop. Yes, it does have an effects loop, and I will check that. Thanks!
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Post by billyguitar on Aug 12, 2006 18:24:04 GMT -7
I think a bad rectifier tube will do that but I'm really not sure. If you changed it too it must be an internal problem.
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Post by kelley on Aug 12, 2006 22:13:20 GMT -7
I think a bad rectifier tube will do that but I'm really not sure. If you changed it too it must be an internal problem. It is also my understanding that a blown rectifier tube or a power tube can cause the 2 amp fuse to blow. Any one have any idea what could cause eithere of those tubes to blow? (if in fact the new tubes were good)
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luke
Full Member
Mini
Posts: 109
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Post by luke on Aug 13, 2006 2:16:46 GMT -7
My MAZ Jr. was blowing fuses. It was a bad recifier tube. I replaced it, the 2 amp & 1/2 amp fuse. Problem corrected.
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Post by tjstrat on Aug 13, 2006 6:09:10 GMT -7
A little off topic... This happened to me a few years back at a small outdoor festival. I set up, turned my amp on... nothing. I checked the fuse. Okay. All connections..? Okay. Reached back into the amp, wiggled the preamp and power tubes... Okay. Wiggled the rectifier... and the BOTTLE part came out without the base. The glue was all there, glass intact... But it just CAME OUT, two conductors just trailing sadly from the base of the glass.
I about fell over laughing, but then realized that at 5 pm on a Saturday in Rockford IL, 20 minutes before start time, my chances of finding a new rectifier were slim at best.
Luckily one of the locally owned stores WAS open and had a solid state replacement. I ordered a couple replacements from Budda that week and the problem never happened again.
But MAN. It came off in my HAND...
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robt
Full Member
Posts: 138
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Post by robt on Aug 13, 2006 9:23:19 GMT -7
I agree with others who point to the recitifier tube, happened to me with my new Maz Jr a few months after I got it...emailed the doc and he sent me one, gratis. Problem solved. Not a problem since. Kudos to the doctor for replying to his emails and solving the problem.
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Post by quinto on Aug 13, 2006 9:50:00 GMT -7
Yes, I vote for a rectifier tube. I had one quit at church once. We went up after the sermon for a song took it off standby and I had nothin'. The JJ's are pretty good. There onle $14 from Bob at eurotubes. At that price everyone should have a spare or two.
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Post by kelley on Aug 13, 2006 10:10:22 GMT -7
I put a new rectifier tube in and it blew the 2 amp fuse. Any one know why that would happen? My MAZ Jr. was blowing fuses. It was a bad recifier tube. I replaced it, the 2 amp & 1/2 amp fuse. Problem corrected.
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Post by hunter6726 on Aug 13, 2006 10:54:45 GMT -7
Whatever you do, DO NOT try a different amperage fuse. It can make for a nice camp fire.
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Post by guitarboy02451 on Aug 13, 2006 12:32:01 GMT -7
Can you bring the amp back to the place you bought it? If they sell Z's they might know a thing or two on getting it back in shape.
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Post by kelley on Aug 13, 2006 16:39:45 GMT -7
It plays again! ;D
First my Guitar center rant. Hate this store with a passion. They treat you like a criminal when you go inside. damn near get strip searched. Spent 100 on blown tubes that I can't return. Lovely! Done ranting.
Second, Bob at Euro tubes is my new hero! Nicest and most knowledgeable person I have ever met in this indusrty. I Just love the ecc81 that he recomended.
Thanks everyone for their input.
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Post by guitarboy02451 on Aug 14, 2006 4:19:56 GMT -7
So, what was the problem?
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