Musician Posted November 14, 2018 Share Posted November 14, 2018 I just have two wall outlets , one is dedicated to the power amp. The rest is shared by all my home theatre equipment ( TV, Foxtel, pre, power, blu player,etc) and my audio pre amp, phono stage and turntable including some led lights for mood lighting. Noticed the sound to loose life when I power the new led lights but the life came back when I switched it off. This made me wonder whether there was dc and or noise be introduced by the USB led lights. If that is the case What should I get so that noise and or dc can be filtered out. Or should I get someone to install more wall power outlets, would that be a cheaper option. Link to comment Share on other sites More sharing options...
Musician Posted November 15, 2018 Author Share Posted November 15, 2018 No one? Link to comment Share on other sites More sharing options...
andyr Posted November 15, 2018 Share Posted November 15, 2018 On 14/11/2018 at 8:59 PM, Musician said: I just have two wall outlets , one is dedicated to the power amp. The rest is shared by all my home theatre equipment ( TV, Foxtel, pre, power, blu player,etc) and my audio pre amp, phono stage and turntable including some led lights for mood lighting. Noticed the sound to lose life when I power up the new led lights but the life came back when I switched it off. This made me wonder whether there was dc and or noise be introduced by the USB led lights. Could well be. What 'thing' has the USB socket which you plug these LED lights into? On 14/11/2018 at 8:59 PM, Musician said: If that is the case What should I get so that noise and or dc can be filtered out. You might have to try out some things - to see if they work. If the LED lights are creating DC which goes back into the mains (and upsets your hifi components) ... then a DC blocker will stop that. OTOH, if the LED lights are injecting HF hash back into the mains (and upsetting your hifi components) ... then you need a hash filter. That's why I asked where are the LED lights getting their power from. On 14/11/2018 at 8:59 PM, Musician said: Or should I get someone to install more wall power outlets, would that be a cheaper option. Given they would all be running off the same circuit, I doubt if it would solve your problem. Andy Link to comment Share on other sites More sharing options...
Musician Posted November 15, 2018 Author Share Posted November 15, 2018 The USB lights are connected to a multi USB charger via USB extension cables. Link to comment Share on other sites More sharing options...
VanArn Posted November 15, 2018 Share Posted November 15, 2018 LED lighting can cause interference with RF equipment and USB chargers which employ switch mode power supply technology can also be a problem. These items should all comply with ECM standards and shown to be tested via an appropriate authority. A quality power conditioner/ mains filter should be tried on a trial basis and if this fails to cure the problem, then maybe the cheapest solution may to be use conventional mains connected LED or halogen lights . Link to comment Share on other sites More sharing options...
Aussieamps Posted November 27, 2018 Share Posted November 27, 2018 @Musician Have a look at one of my mains conditioners it could solve your issues as it has for others. https://holtonprecisionaudio.com/collections/power-conditioners/products/holton-dc-blocker-one 1 Link to comment Share on other sites More sharing options...
Zaphod Beeblebrox Posted November 27, 2018 Share Posted November 27, 2018 On 16/11/2018 at 9:44 AM, VanArn said: LED lighting can cause interference with RF equipment and USB chargers which employ switch mode power supply technology can also be a problem. These items should all comply with ECM standards and shown to be tested via an appropriate authority. A quality power conditioner/ mains filter should be tried on a trial basis and if this fails to cure the problem, then maybe the cheapest solution may to be use conventional mains connected LED or halogen lights . Power conditioning only works on the appliance that is causing the problem. It is a waste of time and money to put a mains conditioner on the item which is 'receiving' the interference. RFI will not make it through a typical power supply. It can only be transmitted. But you already know this. Fundamentally, you are correct, in that all products should meet basic standards WRT causing interference problems. Link to comment Share on other sites More sharing options...
Southerly Posted December 5, 2018 Share Posted December 5, 2018 Do you use the cheapskate method in Oz the same as the UK - ring mains. In Europe everything is on spurs. Whatever a good investment would be an isolation transformer. I'm sure there must be a manufacturer in Oz as they are heavy things and shipping from elsewhere expensive. Thought about buying one for where I live in France, I had a terrible humming from the PSU for my phono stage for about 2 weeks - a free gift from a near neighbour. Link to comment Share on other sites More sharing options...
andyr Posted December 5, 2018 Share Posted December 5, 2018 7 hours ago, Southerly said: Do you use the cheapskate method in Oz the same as the UK - ring mains. In Europe everything is on spurs. Always 'spurs' in Oz. 7 hours ago, Southerly said: Thought about buying one for where I live in France, I had a terrible humming from the PSU for my phono stage for about 2 weeks - a free gift from a near neighbour. If it was the power transformer that was buzzing ... sounds like DC on the mains (courtesy of your neighbour). Andy Link to comment Share on other sites More sharing options...
Southerly Posted December 10, 2018 Share Posted December 10, 2018 On 05/12/2018 at 8:42 PM, andyr said: Always 'spurs' in Oz. If it was the power transformer that was buzzing ... sounds like DC on the mains (courtesy of your neighbour). Andy exactly Andy, that's why a well built isolation Tx is a very good idea. Link to comment Share on other sites More sharing options...
andyr Posted December 10, 2018 Share Posted December 10, 2018 45 minutes ago, Southerly said: exactly Andy, that's why a well built isolation Tx is a very good idea. Certainly, Stuart - for a source component. But for a power amp, you need a massively over-specced isolation Tx to not degrade the dynamics of the amp ... so a DC blocker may be a better idea. Andy Link to comment Share on other sites More sharing options...
Ittaku Posted December 12, 2018 Share Posted December 12, 2018 On 11/12/2018 at 5:38 AM, andyr said: Certainly, Stuart - for a source component. But for a power amp, you need a massively over-specced isolation Tx to not degrade the dynamics of the amp ... so a DC blocker may be a better idea. If you have a class A amp, you are either getting enough current or you're not, though. So that would be an exception to this rule you're suggesting. Link to comment Share on other sites More sharing options...
andyr Posted December 12, 2018 Share Posted December 12, 2018 1 hour ago, Ittaku said: If you have a class A amp, you are either getting enough current or you're not, though. So that would be an exception to this rule you're suggesting. Not quite sure I understand what you're saying, Con? That for a Class A amp, it doesn't matter what the VA rating of the isotran is? Or if the current draw of the amp is 'X amp' - then provided the isotran is specced to deliver 'X amps' on its secondaries ... there will be no degradation of the sound? If #2, I'm presuming a Class A amp does not have a variable current draw - which increases with bass transients? Andy Link to comment Share on other sites More sharing options...
Ittaku Posted December 12, 2018 Share Posted December 12, 2018 (edited) 11 minutes ago, andyr said: Not quite sure I understand what you're saying, Con? That for a Class A amp, it doesn't matter what the VA rating of the isotran is? Or if the current draw of the amp is 'X amp' - then provided the isotran is specced to deliver 'X amps' on its secondaries ... there will be no degradation of the sound? If #2, I'm presuming a Class A amp does not have a variable current draw - which increases with bass transients? Number 2. Class A amps draw exactly the same current irrespective of how much power they output, so either they're getting enough current or they're not and will never experience any kind of "sag." Consequently, heavily class A biased amps (like mine) that basically never go into class B operation will also behave the same. Edited December 12, 2018 by Ittaku Link to comment Share on other sites More sharing options...
andyr Posted December 12, 2018 Share Posted December 12, 2018 1 hour ago, Ittaku said: Number 2. Class A amps draw exactly the same current irrespective of how much power they output, so either they're getting enough current or they're not and will never experience any kind of "sag." Consequently, heavily class A biased amps (like mine) that basically never go into class B operation will also behave the same. Aah, OK - thanks! Andy Link to comment Share on other sites More sharing options...
.thumb.jpeg.cfeb6974459d30233ba06a6968de5cba.jpeg)
Recommended Posts