High pitched sounds from going through a power supply to an amplifier?
Jun 25, 2015 at 4:05 PM Thread Starter Post #1 of 7

TheGiantHogweed

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I hope this thread is in the right place. I also hope the title is clear enough.
 
I seem to be having a problem that I can't understand. I have recently bought an LED strip with a dimmer switch and a power supply. This is nothing audio related but however, when I adjust the dimmer switch, my amplifier (Pioneer A-209R) allows the buzz of the power supply for my LED strip to go through to my speakers. This only seems to happen when my amplifier isn't on Direct. I like to turn the treble up a bit, so I prefer not to have it on direct as I can't adjust anything. I did somehow expect the power supply for the LEDs to make a quiet buzz. I just didn't expect it to pass through my wall sockets in my room!
 
I first plugged my LED power supply into the same 5 gang extension as my amplifier. I thought that could be related. I then tried in the spare wall socket and that sound still strangely travels to my speakers if my amplifier isn't on Direct. 
 
Is there such a thing as a plug that can filter out all noise that is especially for audio equipment. I don't know anything about this type of stuff so I can't be sure if such a thing exists. 
 
 
Thanks.
 
Jun 25, 2015 at 5:50 PM Post #2 of 7
You could try the Tacima mains conditioner but there are no guarantees it will 100% be able to filter out your leds switching psu in the dimmer. Also.. finding a mains conditioner that allows full amperage to power hungry amps do cost a lot more money. Id be more inclined to try and replace the led psu  (transformer) for another low ripple (less noisy) item before going down the filter route.
 
Jun 25, 2015 at 6:26 PM Post #3 of 7
  You could try the Tacima mains conditioner but there are no guarantees it will 100% be able to filter out your leds switching psu in the dimmer. Also.. finding a mains conditioner that allows full amperage to power hungry amps do cost a lot more money. Id be more inclined to try and replace the led psu  (transformer) for another low ripple (less noisy) item before going down the filter route.


Well, it was a very cheap power supply off Ebay. Does the job but I just didn't expect the sound to travel to the power supply for my amplifier. My 5 gang extension has switches and I wouldn't want one without.
 
This is the sort of power supply I am using:
http://www.ebay.co.uk/itm/DC-12V-2A-UK-Power-Supply-Adapter-led-strip-transformer-/220779353683?pt=LH_DefaultDomain_3&hash=item3367799653
 
It isn't the exact one though but close enough to work out what I am using. It probably will be cheaper to search around and get a better LED power supply that doesn't have a high pitched sound when dimming if that is what is causing it. Not that I can tell that before I buy though.
 
I will probably just have to ether turn the light on full or use my amplifier on Direct the whole time.
 
Sorry that this topic isn't really audio related but it does affect my PC audio so in a way it is.
 
Thanks for the help though.
 
Jun 25, 2015 at 6:45 PM Post #4 of 7
Do you have any old 12v laptop transformers lying around? They are generally much better quality lower ripple items than the cheap ebay item you linked.
Alternatively buy a decent one from maplin and if it still causes similar issues, take it back and swap for another... and so on.. until you find one that works for you. They aren't the cheapest I know but they will take returns (avoids postage fees) which will work out cheaper in the long run.
 
Jun 25, 2015 at 7:00 PM Post #5 of 7
A venom Defender might work for blocking the noise. Plug it into the same outlet your amp is plugged into.
 
http://www.shunyata.com/our-products/pwr-dist/50-power-dist-ven-series/93-venom-defender
 

 
Jun 26, 2015 at 9:10 AM Post #7 of 7
 Do you have any old 12v laptop transformers lying around? They are generally much better quality lower ripple items than the cheap ebay item you linked.
Alternatively buy a decent one from maplin and if it still causes similar issues, take it back and swap for another... and so on.. until you find one that works for you. They aren't the cheapest I know but they will take returns (avoids postage fees) which will work out cheaper in the long run.


I don't have any suitable laptop power supplies no. I have one spare but it it is dell and it is the incorrect size. Can't remember the voltage. I only need it to be a 2A supply. I hope it won't matter if I go beyond that.
 
I have 2 maplin stores quite close to me so thanks for that suggestion. I might go there ans see what they could help me with.
 
Quote:
 Before you buy anything try moving the dimmer as far from the amp and the rest of audio setup as possible.
Chances are that you're getting RF interferences from the dimmer and not through the power line.

Thanks a lot for mentioning this. Has helped a lot. It turns out that my amplifier doesn't like the LED strip being near it. I moved the Led strip away and there was no noise, no matter how close the dimmer was. If I moved the dimmer away and put the LED strip right next to my amplifier, then the noise it made was very obvious.
What it seems is that my amplifier amplifies the exact noise the power supply makes when I use the dimmer switch. It only interfears if the LED strip is close to my amplifier.
 
The place I have the strip located is under the shelf that my amplifier is on.
 
Do you think that since it is the cheap power supply that adds this buzz to everything that this issue may be solved by getting a better power supply as Ari33 suggested?
 
I think I will go to maplin and show them my LED strip, power supply and dimmer switch and see what they recommend.
 
Thanks everyone for this help.
 
(Edit)
http://www.amazon.co.uk/gp/product/B00OB5Q4SW?psc=1&redirect=true&ref_=oh_aui_detailpage_o03_s00
This is the exact dimmer I bought if it helps. The dimmer itself makes no noise at all from 1 to 100% so I don't think that is at fault. I could be wrong though.
 

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