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Post by thatstatuemoved on Jan 31, 2013 12:09:33 GMT -7
I have a new model maz 18 nr model. I usually run the master from 3 to wide open and volume around 11 to 12 0'clock. In a quiet room the amp really has alot of hum. I can set my maz 38 beside it with identical settings and it is not nearly as loud. I was just wondering if this is normal for the 18 or if I have something going on. Thanks for any advice.
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Post by benttop (Steve) on Jan 31, 2013 13:22:54 GMT -7
Not normal. If your output tubes are not matched very well, you can get a lot of hum. There are a number of other possibilities. For example, if you turn the master down, and the hum goes away, that would indicate it's NOT a power tube. Turn all your knobs while listening - do any of them affect the hum? Also, pull the PI tube and turn the amp on. Is it still humming? These tests help isolate where the hum is coming from, which points to different approaches to rectifying the issue.
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Post by thatstatuemoved on Jan 31, 2013 13:26:39 GMT -7
Steve--thanks for the info--I appreciate it very much. Will try your advice. Gracias!
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Post by thatstatuemoved on Feb 1, 2013 8:31:20 GMT -7
Talked with Don and he told me to check V1 and sure enough had a noisy tube in there. Replaced the tube and annoying hum went away. Wow those tubes are fairly new and already bad.
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Post by benttop (Steve) on Feb 1, 2013 10:08:52 GMT -7
Yeah, it is getting harder and harder to find decent examples these days. If you have good preamp tubes, hang on to them!
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