Sorry for the alarmist subject header, but that's what it sounded like at the rehearsal hall last night. Right in the middle of a song, the loudest buzzing I've ever heard--in fact the loudest sound I've ever heard from this amp. Snapped the standy switch down, gave it a few seconds, then back up and fine. One song later, the same thing, so I called it a night.
It's been having intermittent problems over the past 2-3 months (third owner, bought on eBay a year ago). Started with loud crackling and popping when standby switch is turned off. I read a lot of threads in the Jr forum for advice, and here's what I've done so far:
-changed all tubes a month ago -changed microphonic reverb return tube after that -changed reverb driver tube (reverb control was acting funny--almost acting like another stage of gain) -took out reverb tank for inspection (the little wires appear fine) -took the chassis out and tightened jack nuts (reverb out was a little loose) -carefully retensioned rectifier tube socket (it was crackling when moved)
I don't think I damaged anything inside the amp when I did all this, but it's possible.
Any advice? Still a tube issue, or something else? (I've got some NOS tubes coming from Mike at KCA). Should I take it to my local amp tech?
Thanks in advance for any help. I love this amp, but the issues are vexing.
Post by heynewguy (Ol’ Bill) on Apr 6, 2007 11:00:13 GMT -7
The same thing happended to my Maz Jr with the loud buzzing sound. I emailed Doc and he said to make sure that the reverb send and return were in real tight. I checked it and it solved the problem. I hope this helps.
Since you had the reverb tank out i'm assuming the connections are alright . Sounds like it could be arcing somewhere in the circuit and capacitors can do that but that's just a guess . I'm agreeing with Lefty on this one , get in touch with the Doc , sounds like an issue for him to resolve .
Okay, so an update. I talked to the Doc, and he said it was likely a component failing or something coming unsoldered, and recommended that I have a local tech go through the amp. Mr. Ho (here in Vancouver) isolated the problem to the preamp section, found no bad components, but went through and resoldered a bunch of connections, suspecting a cold solder joint. I got the Maz back today and it seems to be working fine. Many thanks to you guys and to the Doc for your advice and support! The Maz is back!
I don't know specifically--he said he went through the preamp section and reflowed the solder connections in "a lot of places." Sorry for the lack of info... The amp was used at volume for about 3 hours last night and no problems.
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