Vintage HiFi Audio Forum
Audio Discussion => General Discussion => Topic started by: RnR on March 30, 2017, 12:26:00 PM
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Hi,
I am in the process of moving in to a new house, and though I have not yet hooked up my stereo, I have noticed bad RF and hum issues with my guitar amps. This doesn't happen with 99% of the receptacles I plug my amp into, and it's been around. Now I'm worried the same issues will be had with my stereo amps.
The house is in a highly populated area and located on the corner, right near a big ol' transformer :( . There is also a satellite dish on the roof from the previous owner, could this be attributing to it?
Anyone else have these issues? What did you do to remedy the problem?
Power conditioners..isolation transformers.. what works?
Thanks in advance
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Another move? Busy man!
My house is ancient, with ancient wiring and nearly completely un-grounded. First thing to check is whether yours is grounded, you can get a little device at Home Depot or the like. If it isn't you may have a something of a large issue on your hands. I ran a dedicated and grounded line out of my breaker box for the stereo in particular and wish I had a second free slot to run a second for amp alone, but it ain't happening anytime soon.
For guitar amps, hum seemed to come from some outlets worse than others and some amps worse than others (haven't played my ancient 'blackface' Vibro Champ in years because of this. I do have some plugs that reduce hum to some degree.... when I get home I'll see what they were called, they might help with or without grounding issues.
It could just be that transformer and a need for power conditioning.
Cheers
Tom
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Did you try a ground lift with the amp? Does it make any difference? First thing I would do is test the outlets for proper wiring and good ground.
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Tom, I didn't know that you played.
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I recently ran a new ground installed from my breaker box, it made a very significant improvement. I know that others have added whole house conditioners, dedicated lines and multiple grounds with good results.... Also, interesting is that when using multiple outlets, it helps to make sure that the breakers are not sharing the same rail. Helps eliminate reduce ground loops...
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RT-do you have an RF problem, or hum? For hum, reversing two prong plugs sometimes helps. If the plug is polarized, get a 3 to 2 wire adaptor and file the polarized prong so it fits into the non-polarized side of the outlet. Isolation transformer work, but good ones aren't cheap.
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Tom, I didn't know that you played.
I do. Not particular talented, completely self-taught but it's nice stress relief and I truly adore guitars as works of art.
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RT-do you have an RF problem, or hum? For hum, reversing two prong plugs sometimes helps. If the plug is polarized, get a 3 to 2 wire adaptor and file the polarized prong so it fits into the non-polarized side of the outlet. Isolation transformer work, but good ones aren't cheap.
For some odd reason, I have never had much issue with RF/hum except with tube guitar amps. I'm not sure what the difference would be that would cause the difference between, say... my Quicksilver GLA and the fore-mentioned Vibro Champ (or Deluxe, or Pro Junior, etc.) but -most- of the ungrounded sockets make them squawk and hum like crazy. I use the 3->2 adapters all over the house as my sockets are so old they don't even have the ground socket...
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I really don't KNOW but, if I were to guess I'd bet it's due to the high gain of the guitar amp's preamp section.
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Do they hum even when the guitar is not plugged in? Single coil pickups are lousy for noise. That why they call a dual coil a humbucker.
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Do they hum even when the guitar is not plugged in? Single coil pickups are lousy for noise. That why they call a dual coil a humbucker.
They do, though not as loud. ...as do humbucking loaded guitars. Unfortunately for me, I prefer P90 loaded guitars, the ultimate in noisy pickups.
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I recently ran a new ground installed from my breaker box, it made a very significant improvement. I know that others have added whole house conditioners, dedicated lines and multiple grounds with good results.... Also, interesting is that when using multiple outlets, it helps to make sure that the breakers are not sharing the same rail. Helps eliminate reduce ground loops...
Jim,
Good to know.. I'll have to see if it is properly grounded. I'm guessing so just because when I plug a tester into the outlet's it has a little "grounded" light that appears. Maybe could use a more solid ground connection though
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Thanks for the replies so far. Last night after work I uninstalled the satellite dish, and tore out all of the Verizon Fios lines/boxes in the house. Boy that felt good to whip that 3 ft wide dish off the roof, the neighbors must think I'm nuts! Not sure the dish had anything to do with it, but it was pretty ugly and archaic.
I notice that the the living room (room closest to street transformer) is the room where RF is most prominent in the signal. Ron, I have read that amps that get most of their gain from the pre-amp section are more susceptible to picking this stuff up. A la my Mesa.
Maybe a whole-house conditioner is in order for me. Or possibly an iso transformer for my stereo amps, since they are in the room that seems to be the worst. If anyone has an iso that they aren't using at the moment, maybe you could stop by for a listening session one evening and we could test if a difference can be heard? Try before I buy..
Lastly,
The house I bought was built in 1910 with knob and tube wiring. Since then the previous owner re-did the all the electric, updated the panel, 3 prong receptacles throughout, BUT left one section of knob and tube that is still in use for a few overhead basement/bathroom lights.. This is not the circuit I am getting problems with FYI, but I do plan on getting this circuit replaced, as it runs through a section with insulation and is a fire hazard. Maybe at that time I can assess the grounding/house conditioner/dedicated line ideas.
Can anyone reommend reliable and affordable electrician that works in Pittsburgh? Thanks again
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Had an electrician install the ground. They drove two rods at least 5 ft into the ground.
Just changing the position of a breaker within the box can make a difference. Note some boxes alternate rails every breaker in the rows, others just use the two different sides. Easy to see... just be careful please. Lastly, if you shut off the whole feed, you can re-twist/ more tightly twist the grounds together to make sure that they are making good contact! Again be careful!
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If rf is a problem I would use shorting plugs in all of your unused input sockets. They are very easy to make and all you need are a bunch of cheap RCA plugs.
Ron
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Rock and Roll,
I think you were down in Lawrenceville the last time we talked. Where did you move to?
Houses are fun!
Good luck,
Mike
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I finally found my spare Hum X plug, these worked relatively well in my ungrounded house, may do better for you:
http://ebtechaudio.com/humxdes.html (http://ebtechaudio.com/humxdes.html)
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RnR-do you have any cable TV gear plugged into any of the audio, including the video monitor, or a digital connection between a cable box and receiver? Cable is notorious for introducing 60 hz hum.
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Rock and Roll,
I think you were down in Lawrenceville the last time we talked. Where did you move to?
Houses are fun!
In Bloomfield Mike -- Hoping to have people over once I get everything set up again!
Good luck,
Mike
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RnR-do you have any cable TV gear plugged into any of the audio, including the video monitor, or a digital connection between a cable box and receiver? Cable is notorious for introducing 60 hz hum.
No cable hooked up MacGeek, but there was that Verizon Fios box that I have since removed.
I am going to do some more testing this week. I have removed the Direct TV dish, all associated wiring, Verizon Fios box/panel and it's wiring, and also purchased a Tripp-Lite noise suppressor. If the problem still persists, I'm going to have to consider some other options. I'll report back after some proper testing.. Thank you
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I finally found my spare Hum X plug, these worked relatively well in my ungrounded house, may do better for you:
http://ebtechaudio.com/humxdes.html (http://ebtechaudio.com/humxdes.html)
Cool!
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Easiest solution... buy a new house...