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Topic: Help w/my Amp Problem |
Dennis Olearchik
From:
Newtown, PA
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Posted 18 Apr 2004 6:25 am |
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I bought a new Fender Vibrolux Custom Reverb amp from my local music store (as I really liked the way it sounded w/both single coil and humbucker guitars). It seemed very quiet (but not not dead quiet) at the store. Then again, there were background noises from other customers, music playing, etc.).
Well I get the amp home, and to my surprise and disappointment, I immediately heard a very loud hum with every guitar I played through it. Touching the bridge or strings noticeably quieted it down but I didn't need to do that at the store.
The amp also made intermittent crackling sounds and reverb type pings when the guitars were plugged in (after maybe 30 + minutes) even when I wasn't playing anything. The use of the tremolo feature also made the the amp much noisier. And to top it all off, I heard a radio station broadcast through the amp (although faintly).
I tried changing all the tubes, checked the speaker connections, hooked the amp up to a $200 Furman power/line conditioner, moved the amp to different outlets in the house, tried different single and humbucking coil guitars, used a George-L instrument cable - all of which didn't quiet down the amp.
The only other amp (tube) I have isn't dead quiet either, is noisier from some outlets than others (but is no where near as noisy as the Vibrolux). And the other amp quieted down to a whisper through the Furman and one of our bedroom outlets (but the Vibrolux didn't).
I did return the amp and my sales guy said he played it afterwards for an hour and didn't get all the noises I heard - which was my original experience at the store - which confuses the hell out of me. But then again, I'm really not savy about amp/guitar electronics or home electrical wiring, grounding, etc.
So I'd truly appreciate any insights, advise, suggestions (or similar experiences) you may have as to what caused all these "problems" at my home but not at the store.
Thank you very much.
Dennis
p.s. I also have a "wireless" pc network in my house (just in case the base station and the outlet wiring it's connected to could be a factor in any of this).
[This message was edited by Dennis Olearchik on 18 April 2004 at 08:12 AM.] |
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Jody Carver
From:
KNIGHT OF FENDER TWEED
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Posted 18 Apr 2004 8:01 am
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Dennis
From what you describe and I'm not an engineer of sorts. But it sounds like a un-disclosed source of interference within your home. I doubt the amp itself is the cause.
I would check out what you suspect may be the problem. It might very well be. You have a fine amp.
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Dennis Olearchik
From:
Newtown, PA
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Posted 19 Apr 2004 5:35 pm
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Hi Jody,
You're always the thoughtful gentleman.
Thanks for the reply.
Dennis
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Jim Florence
From:
wilburton, Ok. US * R.I.P.
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Posted 25 Apr 2004 6:09 pm
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Dennis, How old is your home? It sounds to me like you have one of 2 possibilities.
I think your problem might be the distance from the outlet you are using to the closest "ground" of your electrical service, or a charred ground in your electrical breaker box. If your home is fairly new,and
wired to "Code",just pretend I didn't write this.
Jim |
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David Cobb
From:
Chanute, Kansas, USA
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Posted 25 Apr 2004 7:28 pm
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Interesting post.
I can't help, but I'll cry with you.
I have similar problems with my older house.
I brought in another guitar and amp and they hum too, badly.
Gotta be something like Jody or Jim mentioned.
[This message was edited by David Cobb on 25 April 2004 at 08:29 PM.] |
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Darvin Willhoite
From:
Roxton, Tx. USA
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Posted 26 Apr 2004 5:12 am
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A major source of noise in house wiring is light dimmers and variable ceiling fan switches.
------------------
Darvin Willhoite
Riva Ridge Recording
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Ray Minich
From:
Bradford, Pa. Frozen Tundra
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Posted 26 Apr 2004 6:33 am
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Had a PA system in a church once that hummed like he** (get the pun...). Actually it was bad contacts/tired ballasts in the flourescent tube fixtures that caused a bunch of noise. Had to put a scope on the mains to track it down.
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David L. Donald
From:
Koh Samui Island, Thailand
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Posted 26 Apr 2004 6:43 am
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All of the above is possible
Take the amp somewhere else and see if the symptoms remain.
Try with a high quality guitar cord both places.
Move the amp farther from the wall socket.
Also please describe the environment of your playing area where this all happens.
If it isn't happening in the store or another location, then it is something in your house.
If you cut flourecent lights or things electric in the environment this may help test for the problems. Shut things off till the noise goes away.
This may go as far as doing it from the circuit breaker box.
But don't think only the room you're in, it could be from the other side of the wall too.
An electrician might be needed to check out your house system grounds etc. |
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Ray Minich
From:
Bradford, Pa. Frozen Tundra
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Posted 26 Apr 2004 8:06 am
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| It can also be coming from outside of your house, like the neighbor's TV, or an industrial source down the road. Watch out for anything that uses triacs (light dimmers, variable speed drives, power supplies). You may try borrowing an isolation transformer to isolate the amp and identify the culprit. |
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Dennis Olearchik
From:
Newtown, PA
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Posted 28 Apr 2004 6:37 pm
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I truly appreciate the responses.
Ray, where do I get an "isolation transformer"?
Thanks again everyone![This message was edited by Dennis Olearchik on 28 April 2004 at 07:40 PM.] |
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Andrew Buhler
From:
Maryland, USA
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Posted 29 Apr 2004 6:46 am
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| I've read on the Fender Forum that the Custom Vibrolux Reverb does not have a negative feedback loop, thus there is considerably more hum on this amp compared to Fender blackface and silverface amps (that have the NFL; tweed Fenders do not). I think there is a mod available that adds a negative feedback loop to this amp elimnating the hum, but it will render more clean headroom. Do a search on the Fender Forum and you will see many posts on this topic. Hope this helps. |
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Rick Aiello
From:
Berryville, VA USA
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Dennis Olearchik
From:
Newtown, PA
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Posted 30 Apr 2004 3:40 am
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"Your body is 'channeling' noise".
Well I guess that explains hearing the radio station playing "classic disco" thru the amp ;-)
I would rather be channeling "Hanks's Corner" from satellite radio though!
Oh well, I'm going find my old scuba diving suit and put in on while playing (fins and all)!
I'll post pics and test results... [This message was edited by Dennis Olearchik on 30 April 2004 at 04:41 AM.] |
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Rick Aiello
From:
Berryville, VA USA
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Posted 30 Apr 2004 5:01 am
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Me and my "axe" ...
Not pictured ... Grounding anklet |
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Jennings Ward
From:
Edgewater, Florida, R.I.P.
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Posted 30 Apr 2004 4:12 pm
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| HELLO, THE PROBLEMS YOU DESCRIBE, CAN BE TRACED TO A GROUND LOOP:" CONDITION, THE NEW EQUIPMENT DEMANDS A GROUND.. ANOTHER REASON, ALUMINUM WIRE IN THE HOUSE" BAD FILTER CONDINSERS IN THE AMP. DECOUPLING CAPS IN THE AMP LOOSE GROUNDS, BAD SOLDER CONNECTIONS, YES EVEN BAD TUBES, EVEN NEW ONES, THEY WILL LET YOU HEAR RADIO, OR BAD CAPS WILL DO THE SAME, IS CALLED GRID LEAK DETECTION. TO SHORTEN THIS UP, ANY ONE OF THE THINGS I MENTIONED, OR A COMBINATION, WILL CAUSE YOUR PROBLEMS.. CURE, HUNT TILL YOU FIND THE PROBLEM. THAT IS WHAT TECH'S DO BEST. HOPE THIS HELPS . SINC. JENNINGS IN CAPS AGAIN |
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