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Post by bebopamoeba on Sept 16, 2009 8:19:20 GMT -7
My Maz 18 Jr has suddenly started picking up radio signals and it's noisier than usual. This occurs without a guitar plugged in. Also the wall outlet appears to be properly ground. Tube problem or... Help! Thanks.
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Post by Mostrummer on Sept 16, 2009 8:51:39 GMT -7
Try reseating the tubes and tightening the chassis bolts on the top of the amp. If that doesn't help, swap tubes one at a time. Good luck!
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Post by benttop (Steve) on Sept 16, 2009 11:40:35 GMT -7
Reverb model? If so, you may have a loose connection there. In worst cases you might have to add a ferrite bead to the reverb cables.
First stop is the mechanical stuff - tighten everything and make sure it's all secure. Then make sure of the tubes. Then check the reverb cables etc.
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Post by DRZ on Sept 16, 2009 11:45:10 GMT -7
Also check your Reverb Cables. They may be a bit loose at the chassis connecting point. Pull each one out one at a time and try to squeeze the RCA jacks ground tabs so the jack fits tightly.
If this happened all of a sudden possibly a bad V3 ( 12AT7 ) or bad V4 ( 12AX7 ).
If RF interference still persists Radio Shack sells a snap on Ferrite Bead ( Radio Shack Part Number 273-069 ) buy two and snap on each reverb cable.
DR.Z
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Post by Phil (aka Phil) on Sept 17, 2009 5:00:38 GMT -7
We had a "little" thing here called the VOA (Voice of America) which was a govenment owned broadcast facility powerful enough to transmit around the world. One of the things I do here at the electric utility is troubleshoot RFI (radio frequency interference) and simiar problems. Back in the '80s and early '90s when the government was still operating the VOA it was quite common for residents living in the vicinity to pick up various Spanish language programs on whatever metal object could resonate at or near the frequency in use, including kitchen toaster elements, their telephones, metal fences, and even tooth fillings!
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Post by bebopamoeba on Sept 17, 2009 9:34:24 GMT -7
Thanks for all the knowledgeable advice. Tubes were tight. A couple were low glow. I live about 30 min away from The Tube Store, so I treated the Maz to complete new set of tubes. Much less interference but still audible. Then I saw the posts by benttop and the creator himself, so I cranked the reverb. Yep, more reverb meant more Top 40 radio. I like using the amp's reverb, so I'll check out the ferrite beads. Thanks again for all your help, guys. Ferret Beads!
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