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Topic: Question for /mike Brown.112 a/c hum |
Tracy Sheehan
From: Fort Worth, Texas, USA
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Posted 21 Nov 2004 6:12 pm
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Seems i read some time back on the forum about some were getting a hum on their Nv112.I bought a new one last week and it honks.A great amp but after using it a while it did develope a bad hum.I got the multi meter out and checked all the chords.Nothing wrong there.I know it has always been said to not go to a two prong power plug.This is the first amp i ever had that diidn't have an off and own switch where you could reverse the polairty.So i got a two prong adapter for the power plug and turned it over,pluged back into the wall a/c unit and got rid of the hum.Did i miss something Mike,and any comments?Thanks much in advance.Tracy [This message was edited by Tracy Sheehan on 21 November 2004 at 06:15 PM.] |
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John Daugherty
From: Rolla, Missouri, USA
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Posted 22 Nov 2004 7:03 am
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Tracey, you are probably getting the hum from equipment in the signal path between the guitar and amp. It is important to use the grounding power cord on the amp (for safety). Use the 2-prong adapter on your effects, tuner, etc. to locate the device causing the ground loop.
I have to use a 2-prong adapter on my Korg DTR-1 tuner to eliminate the hum. I am sure you will be able to ground the amp after isolating the offending equipment with the 2-prong adapter.
PLEASE ground that amp. We don't want you to have a shocking experience. Of course, if you prefer curly hair and a short life........leave the amp ungrounded. Let us know what you find.....JD |
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Mike Brown
From: Meridian, Mississippi USA
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Posted 22 Nov 2004 7:11 am
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I agree with John's suggestion. However, let me know if the problem continues. I can be reached toll free at 1-877-732-8391, ext.1180. |
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Jerry Roller
From: Van Buren, Arkansas USA
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Posted 22 Nov 2004 7:20 am
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I used this great little amp Saturday night on the Little O' Opry show. No hum, sounded great. Sunday night our Gospel group played at a Church in Oklahoma and I could not eliminate the hum. I did not take time to lift the ground on the DTR 1 and/or Lexicon MPX1. I did try a ground lift plug on the effects rack as a whole without success. It must have been the lights in the Church. The next time it happens I will try direct from guitar to the amp and see what happens. It sure is a great sounding amp, however.
Jerry |
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Tracy Sheehan
From: Fort Worth, Texas, USA
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Posted 22 Nov 2004 8:54 am
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Thanks all but i will try later to call Mike Brown.This is not RF floating around.It is a 60 cycle AC hum.Nothing serious but it is a polarity problem.I went direct from the steel to the amp with 4 different patch cords i had cheched with an ohm meter and still had the hum.Thanks for your concern and i am no electronc tech,but after being a ham radio operator for 30 plus years i am familiar some what with electronics,but mostly the old tube stuff.ha.Telling my age.Tracy
Oh yes,i also pluged it into the wall socket that is on a seperate line for the A/C only. |
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Bill Hatcher
From: Atlanta Ga. USA
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Posted 22 Nov 2004 9:05 am
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Are you getting this hum with NOTHING plugged in the amp?
If so is the reverb turned off? Any difference? |
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Tracy Sheehan
From: Fort Worth, Texas, USA
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Posted 22 Nov 2004 9:09 am
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Me again.ha.The amp is not the cause of the hum.It is in the a/c line.I just now pluged the amp back into the wall socket with the 3 pron plug.No hum.Need to find a way to reverse the polariy.This is an old problem with ac lines and amps.My LTV 400 had a polarity reverse switch and the old Bandit 65 i still have does also.As i recall the fenders had the switch to reverse the polarity whan an ac hum kicked in.Tracy [This message was edited by Tracy Sheehan on 22 November 2004 at 09:12 AM.] |
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b0b
From: Cloverdale, CA, USA
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Posted 22 Nov 2004 9:20 am
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Moved to 'Electronics' section of the Forum |
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