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Post by dwaynekendall on Jun 4, 2019 11:46:35 GMT -7
Hey everyone, I have a '08 MAZ18 w reverb that I bought a couple months ago but had not been able to really crank till last weekend at a gig. Warm little club and cranked up a bit, into the 2nd song the amp powered off, by the time I had the opportunity to get back there to see what was going on it had regained power. Nothing else on that circuit died. I checked the power plugs to make sure they were in nice tight and went on to next song. It did it again around the end of that tune. Off then back on. I suspected heat issues so moved my fan to behind the amp and it was fine the rest of the night. Is there an actual thermal breaker of some kind going bad maybe or symptom of something else going on? Absolutely loved the amp so need to get it figured out.
2nd question would be has anyone done the Mkii upgrade and was really it worth it. Would like the adjustable boost and smoother lower volume gain control as long as it doesn't have a down side to the amp any...
THANKS!
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Post by digs57 on Jun 4, 2019 12:08:23 GMT -7
Its always something....lol...tube related is my guess/retension tube sockets?...an 08 would only benefit from being in shop regardless of upgrade/check up...the mrk2 upgrade does have a smoother voicing and weather its worth it is up to user in the end...but you are able to get a lower gain/crunch setting on master which is nice at lower volumes,if reverb model its big change there as well...adjustable boost as well is a game changer if your going to use it...very usable.
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Post by dwaynekendall on Jun 4, 2019 13:11:12 GMT -7
Thanks for the reply, I wouldn't think a tube issue would power off the amp but that is why I'm asking here. Hopefully more will chime in. I'll look at the tube sockets.
I like the tone if the amp right now, that is why my concerns of the MKII upgrade. But the added control-ability would be nice. Again, hopefully more will chime in...
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Post by purpletele on Jun 4, 2019 14:28:06 GMT -7
Dwayne,
There are not any heat sensors just one fuse.
if it is a head make sure the Reverb bag is not constricting air flow.
I would replace the power tubes and see if that changes the temp, then I would go after the rectifier.
I doubt that it is the rectifier tube but you should check.
If it a used amp it is possible that someone changed the cathode resistor to run hotter, but that is a remote possibility.
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Post by DRZ on Jun 4, 2019 17:24:15 GMT -7
There is no thermal cut off circuit in the MAZ , or in any of my amps. If the output tubes are original 11 years old it is time for new ones, get the 6N14N's as replacements. I have seem this problem only a few times in the past and in those instances it was a loose fitting power cord on the back panel IEC connector. But your amp maybe old enough to have a fixed power cord, not a detached one , which was the source of the problem in other cases. A loose fuse holder internal spring, or a bad rectifier are the other things that come to mind. You need to verify this happens every time , not just a one time problem, ask the seller if this was a common problem.
Z
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Post by purpletele on Jun 4, 2019 21:49:36 GMT -7
I have seem this problem only a few times in the past and in those instances it was a loose fitting power cord on the back panel IEC connector. Holy moly!! I forgot about that possibility. That has happened at least twice to me and everyone thought I was nuts. My issue was that I didn't have the cord in all of the way, but I have had worn out cords where the IEC connection was loose. Either way it caused a Redplating issue. I am pleased you brought that up, that makes more sense than the tubes, I would expect the tubes to short. Check the cord, I think Z may have nailed it!
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Post by dwaynekendall on Jun 5, 2019 5:58:49 GMT -7
Thanks all for the reply. The fact that it settled down with a fan behind it makes me think tubes based on your responses. I will get a set, should have spares anyway. The power cord seemed tight fitting, not loose at all. But I will try a different one. Y'all rock
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Post by zpilot on Jun 5, 2019 7:09:48 GMT -7
I wish all detachable power cords were the locking-type like QSC uses on powered sub-woofers. I have had several occurrences of power cords loose on power amps.
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Post by purpletele on Jun 5, 2019 7:12:36 GMT -7
Thanks all for the reply. The fact that it settled down with a fan behind it makes me think tubes based on your responses. I will get a set, should have spares anyway. The power cord seemed tight fitting, not loose at all. But I will try a different one. Y'all rock My cord issue was it wasn't plugged in all of the way, it fit well.
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Post by dwaynekendall on Jun 9, 2019 12:11:38 GMT -7
OK, replacing the power cord seemed to fix my problem. Thanks for the responses, now to decide on the MKII upgrade. (think I'm gonna do it)
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Post by purpletele on Jun 11, 2019 23:07:02 GMT -7
OK, replacing the power cord seemed to fix my problem. Thanks for the responses, now to decide on the MKII upgrade. (think I'm gonna do it) Hey, that is great news. I was excited when DRZ mentioned that, because he has seen a thing or two.
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Post by daddyelmis (Greg) on Jun 12, 2019 4:51:20 GMT -7
OK, replacing the power cord seemed to fix my problem. Thanks for the responses, now to decide on the MKII upgrade. (think I'm gonna do it) Was it a bad cord (cracked or something)? Or just not tightly fitting? I’ve never had this happen so I’m wondering what to look for.
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Post by zpilot on Jun 12, 2019 6:35:13 GMT -7
Doc was not happy when he was forced to start putting detachable cables on his amps. I detest them.
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Post by mudman on Jun 13, 2019 20:26:39 GMT -7
I’ve had the bad power cord happen to me as well. Recently had reverb go nuts on my deluxe reverb. The rca jack connection had worked its way loose. Tightened the rca cables and it’s been quiet as a mouse fart since.
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Post by mikefleming on Jul 4, 2019 7:15:47 GMT -7
I had this exact thing happening once due to a bad fuse socket, as Z mentioned.
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Post by daddyelmis (Greg) on Jul 4, 2019 7:40:53 GMT -7
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