Hi folks!
Hoping you can help me solve a very annoying earthing (I think!) problem I have.
The background, I am running the following:
From one wall socket on one end of the room, I have plugged into a 3-way extension socket:
Pioneer DV-575A (not earthed)
Infocus Screenplay 4805 LCD Projector (Earthed)
From another socket at the opposite end of the room the following plugged into a medical grade 4-way IEC distribution outlet:
Quad 34 pre-amplifier (earthed)
Amp6 basic + power supply (not earthed)
Now the projector is attached to the DVD player via 3 shielded phono leads for component video.
In turn the Pioneer Dv-575A is connected to the Quad 34 pre with shielded interconnect.
I am getting a typical kind of earthing hum through the speakers when the projector is switched on. The hum increases as volume is increased on the Quad pre and vice versa. Switch off the projector and the hum goes.
I (foolishly, I know!) tried disconnecting the earth to the projector and this cured the hum completely. unfortunately though when I touched the barrel of the RCA connector I got a shock - not a particularly bad one but it left my hand tingling for a bit.
The really weird thing is I had the same set-up inmy last place and had no problems at all. Do I need to get paranoid and start checking the wall sockets for sound earth connections?
Any help/advice would be appreciated - missing the big screen!
Cheers!
- John
Hoping you can help me solve a very annoying earthing (I think!) problem I have.
The background, I am running the following:
From one wall socket on one end of the room, I have plugged into a 3-way extension socket:
Pioneer DV-575A (not earthed)
Infocus Screenplay 4805 LCD Projector (Earthed)
From another socket at the opposite end of the room the following plugged into a medical grade 4-way IEC distribution outlet:
Quad 34 pre-amplifier (earthed)
Amp6 basic + power supply (not earthed)
Now the projector is attached to the DVD player via 3 shielded phono leads for component video.
In turn the Pioneer Dv-575A is connected to the Quad 34 pre with shielded interconnect.
I am getting a typical kind of earthing hum through the speakers when the projector is switched on. The hum increases as volume is increased on the Quad pre and vice versa. Switch off the projector and the hum goes.
I (foolishly, I know!) tried disconnecting the earth to the projector and this cured the hum completely. unfortunately though when I touched the barrel of the RCA connector I got a shock - not a particularly bad one but it left my hand tingling for a bit.
The really weird thing is I had the same set-up inmy last place and had no problems at all. Do I need to get paranoid and start checking the wall sockets for sound earth connections?
Any help/advice would be appreciated - missing the big screen!
Cheers!
- John
" ... From one wall socket on one end of the room, I have plugged into a 3-way extension socket:
** Pioneer DV-575A (not earthed) ... +++ ... Infocus Screenplay 4805 LCD Projector (Earthed)
From another socket at the opposite end of the room the following plugged into a medical grade 4-way IEC distribution outlet:
** Quad 34 pre-amplifier (earthed) ... +++ ... Amp6 basic + power supply (not earthed) ... Switch off the projector and the hum goes ..."
Yeap, lots of ground loop potential here ... We run into this kind of problem all the time ... connected audio and video equipment strung out on long power lines or separated by distance or plugged into opposing power line phases and on long ground (earth) lines ...
* Put all audio and play back equipment in one location and have them all share a common power plug and common ground (earth) and have the actual display equipment located where it needs to be, sometimes out in the middle of the room, powered from whatever plug (opposite phasing or not) it needs ... THEN run the display cable (only) to the display (projector). IF (and only if) the projector then causes noise (humm) on the audio equipment, the addition of power line filters and interconnect noise reduction or elimination parts could be added.
* If you have newer HDMI players and HDMI / DVI displays like the Infocus above = same, same ... This solution works for our all of our serious, professional customers: Put all audio and play back equipment in one location and have them all share a common ground (earth) and have the actual display equipment located where it needs to be, sometimes out in the middle of the room powered from whatever plug (opposite phasing or not) it needs ... THEN run the display cables (only) to the display (or projector). IF (and only if) the projector then causes noise (humm) on the audio equipment, the addition of power line filters and interconnect noise reduction or elimination parts could be added ... or use optically isolated video adapters. (This will be cheaper in the long run than rebuilding your power lines / room / grounding / remote controlled / new HDMI player audio / visual enviromnent.)
... But we still recommend putting the DVD player, the amp and pre-amp together in one location = always ... 'cause that's where the ground looping can be resolved. (If you insist on scattering your audio / video components around the room, there will almost always be a noise problem in this modern, 50/60 cycle, WiFi / cell phone, wireless, police band, broadcast and aircraft radio navigation society we live in.)
(Mercenary announcement: We ship these kinds of optical isolation display adapters all over the world ... and they reduce noise, feedback, humm and whistles, etc. etc ... in almost any home theater or sports bar environment: http://industrialcomponent.com/opticis/m1201tr.html ... a bit pricy for home equipment, but it sure works = just add fiber: http://industrialcomponent.com/newnex/optiproduct.html ... works up to 1/4 mile !! A big screen, big name display manufacturer had these installed in their corporate headquarters =
😉 
😀 ... also see: http://industrialcomponent.com/opticis/opticalhdmi.html ) 
** Pioneer DV-575A (not earthed) ... +++ ... Infocus Screenplay 4805 LCD Projector (Earthed)
From another socket at the opposite end of the room the following plugged into a medical grade 4-way IEC distribution outlet:
** Quad 34 pre-amplifier (earthed) ... +++ ... Amp6 basic + power supply (not earthed) ... Switch off the projector and the hum goes ..."
Yeap, lots of ground loop potential here ... We run into this kind of problem all the time ... connected audio and video equipment strung out on long power lines or separated by distance or plugged into opposing power line phases and on long ground (earth) lines ...
* Put all audio and play back equipment in one location and have them all share a common power plug and common ground (earth) and have the actual display equipment located where it needs to be, sometimes out in the middle of the room, powered from whatever plug (opposite phasing or not) it needs ... THEN run the display cable (only) to the display (projector). IF (and only if) the projector then causes noise (humm) on the audio equipment, the addition of power line filters and interconnect noise reduction or elimination parts could be added.
* If you have newer HDMI players and HDMI / DVI displays like the Infocus above = same, same ... This solution works for our all of our serious, professional customers: Put all audio and play back equipment in one location and have them all share a common ground (earth) and have the actual display equipment located where it needs to be, sometimes out in the middle of the room powered from whatever plug (opposite phasing or not) it needs ... THEN run the display cables (only) to the display (or projector). IF (and only if) the projector then causes noise (humm) on the audio equipment, the addition of power line filters and interconnect noise reduction or elimination parts could be added ... or use optically isolated video adapters. (This will be cheaper in the long run than rebuilding your power lines / room / grounding / remote controlled / new HDMI player audio / visual enviromnent.)
... But we still recommend putting the DVD player, the amp and pre-amp together in one location = always ... 'cause that's where the ground looping can be resolved. (If you insist on scattering your audio / video components around the room, there will almost always be a noise problem in this modern, 50/60 cycle, WiFi / cell phone, wireless, police band, broadcast and aircraft radio navigation society we live in.)
(Mercenary announcement: We ship these kinds of optical isolation display adapters all over the world ... and they reduce noise, feedback, humm and whistles, etc. etc ... in almost any home theater or sports bar environment: http://industrialcomponent.com/opticis/m1201tr.html ... a bit pricy for home equipment, but it sure works = just add fiber: http://industrialcomponent.com/newnex/optiproduct.html ... works up to 1/4 mile !! A big screen, big name display manufacturer had these installed in their corporate headquarters =
😉 😀 ... also see: http://industrialcomponent.com/opticis/opticalhdmi.html )
Howdy 😀
Thanks for your reply - much appreciated!
Well all my audio equipment IS at one end of the room on the same mains distribution block.
The DVD player and Infocus share the other distribution block at the other end of the room. The DVD-575A is not earthed so I don't really see how moving this to the hi-fi side would improve things, and then I'm faced with the problem of finding component cables which can reach from one end of the room to the other to reach the projector... At present the DVD player is underneath the projector.
Fact is this exact arrangement worked in my last flat with no problems at all. I'm going to run a check of the integrity of the earths in the sockets in the room in question today to make sure they're all sound.
Thanks,
- John
Thanks for your reply - much appreciated!
Well all my audio equipment IS at one end of the room on the same mains distribution block.
The DVD player and Infocus share the other distribution block at the other end of the room. The DVD-575A is not earthed so I don't really see how moving this to the hi-fi side would improve things, and then I'm faced with the problem of finding component cables which can reach from one end of the room to the other to reach the projector... At present the DVD player is underneath the projector.
Fact is this exact arrangement worked in my last flat with no problems at all. I'm going to run a check of the integrity of the earths in the sockets in the room in question today to make sure they're all sound.
Thanks,
- John
P.S. What really concerened me was getting an electrical shock from the barrel of the RCA connector (from the audio outs of the unearthed DVD player) when the earth was disconnected from the Projector. How on earth (pun intended!!) can I get a shock through the audio cable? Surely this points to some major problem somewhere?
Reconnecting the earth to the Infocus projector and the shock from the RCA barrel is gone, but the sound from the speakers has a dirty mains hum...
Reconnecting the earth to the Infocus projector and the shock from the RCA barrel is gone, but the sound from the speakers has a dirty mains hum...
" ... The DVD player and Infocus share the other distribution block at the other end of the room. ... not earthed so I don't really see how moving this to the hi-fi side would improve things ... with the problem of finding component cables which can reach from one end of the room to the other to reach the projector ... "
" ... getting an electrical shock from the barrel of the RCA connector (from the audio outs of the unearthed DVD player) when the earth was disconnected from the Projector. ..."
Yes sssss = see what I mean = get the projector away from the audio
Truth is one, paths are many ... many ground paths, that is ...
So, if you can find audio cables that long, why not video cables ??
Look, having that DVD player a long way from the audio equipment is partly the problem = long audio lines make for lots of opportunities for noise, hummmmm, etc. That's why we sell so many DVI / HDMI / VGA / NTSC extensions (optical and otherwise) .... .... To get the audio sources located close to the sound equipment and the (often noisy) display / projector far away from the sound equipment ... 
😎
" ... getting an electrical shock from the barrel of the RCA connector (from the audio outs of the unearthed DVD player) when the earth was disconnected from the Projector. ..."
Yes sssss = see what I mean = get the projector away from the audio
Truth is one, paths are many ... many ground paths, that is ...
So, if you can find audio cables that long, why not video cables ??
Look, having that DVD player a long way from the audio equipment is partly the problem = long audio lines make for lots of opportunities for noise, hummmmm, etc. That's why we sell so many DVI / HDMI / VGA / NTSC extensions (optical and otherwise) .... .... To get the audio sources located close to the sound equipment and the (often noisy) display / projector far away from the sound equipment ...
😎
Hi!
Thanks for your reply!
So it's better to have long component video leads than it is to have long audio ones?
I will try moving the projector onto the distribution block for the other components and see if that improves matters first - fingers crossed!
- John
Thanks for your reply!
So it's better to have long component video leads than it is to have long audio ones?
I will try moving the projector onto the distribution block for the other components and see if that improves matters first - fingers crossed!
- John
😀 ... " will try moving the projector onto the distribution block for the other components and see if that improves matters first ..."
Check polarity / reverse polarity on your ungrounded equipment as well = try it one way, then the other. Often rolling over the power cord connections (reversing common and power, black and white, opposite phases) will make for a better balanced power v. common on the internal power supplies of one device or another = sometimes the noise goes away, sometimes not ... but having all equipment powered from the same point ...
Check polarity / reverse polarity on your ungrounded equipment as well = try it one way, then the other. Often rolling over the power cord connections (reversing common and power, black and white, opposite phases) will make for a better balanced power v. common on the internal power supplies of one device or another = sometimes the noise goes away, sometimes not ... but having all equipment powered from the same point ...
electricity is somthing I know more about. not much experiance with ground loop problems but I know about load, wire guage, draw through braker.
While conecting everything through the same receptical may help your problem the braker and wire to the outlet must be able to handle that load, dont upgrade the breaker if you start to trip it.check your breaker box for an extra space and check into a new receptical for your room that is red colored. the red ones need a new wire to them that has an extra wire in (ground, black,white,red) this set up ive found is best for sensitive equipment (made for it).the receptical is a bit more expensive and a electrition for sure is expensive but if you could ad this to youre house for hifi reasons its the way to go. but to be perfect youd run a line to each component that draws a lot of power (large lcd,hi power stereo,computor,etc).
On grouding if receiving radio signals (am,FM,shortwave) it realy helps to run the ground from the component chasy with coper to the out side and bury to
a copper pole in the ground a few feet deep this has made my antenas work the best ever. I guess off subject hope this makes some sence about the red colored recepticals (cant remember their name)
While conecting everything through the same receptical may help your problem the braker and wire to the outlet must be able to handle that load, dont upgrade the breaker if you start to trip it.check your breaker box for an extra space and check into a new receptical for your room that is red colored. the red ones need a new wire to them that has an extra wire in (ground, black,white,red) this set up ive found is best for sensitive equipment (made for it).the receptical is a bit more expensive and a electrition for sure is expensive but if you could ad this to youre house for hifi reasons its the way to go. but to be perfect youd run a line to each component that draws a lot of power (large lcd,hi power stereo,computor,etc).
On grouding if receiving radio signals (am,FM,shortwave) it realy helps to run the ground from the component chasy with coper to the out side and bury to
a copper pole in the ground a few feet deep this has made my antenas work the best ever. I guess off subject hope this makes some sence about the red colored recepticals (cant remember their name)
" ... may help your (?) problem the braker and wire to the outlet must be able to handle that load ... "
That is why I suggested placing the DVD player with your audio and running the projector separately ... * digital and analog video are more immune to hummmm, power line noise, outside interference and ground loop problems than audio ...* AND putting the load of your audio system on one breaker and the video display on another = splits the total power load over two separate breakers ... 🙄
" ... On grouding if receiving radio signals (am,FM,shortwave) it realy helps to run the ground from the component [chassis] with coper to the out side and bury to a copper pole in the ground a few feet deep this has made my antenas work the best ever. ..."
Yes, all well and good. But you won't know what to fully ground until you isolate a solution ... then you can add as many true earth grounds as you want to improve upon a better solution ... (IMOP: a careful analysis of doubled or tripled, redundant grounding scenarios may prove to be a time and money waster. Consider: if you have long audio lines and a resulting hummm problem, the addition of extra grounding points and equipment may exaserbate the problem, just as the healthy grounds inprove a radio receiver reception, healthy grounds on your audio system may make those long audio lines work more like your radio antenna and actually increase the hummmmm mmmmm mmm problem.)
That is why I suggested placing the DVD player with your audio and running the projector separately ... * digital and analog video are more immune to hummmm, power line noise, outside interference and ground loop problems than audio ...* AND putting the load of your audio system on one breaker and the video display on another = splits the total power load over two separate breakers ... 🙄
" ... On grouding if receiving radio signals (am,FM,shortwave) it realy helps to run the ground from the component [chassis] with coper to the out side and bury to a copper pole in the ground a few feet deep this has made my antenas work the best ever. ..."
Yes, all well and good. But you won't know what to fully ground until you isolate a solution ... then you can add as many true earth grounds as you want to improve upon a better solution ... (IMOP: a careful analysis of doubled or tripled, redundant grounding scenarios may prove to be a time and money waster. Consider: if you have long audio lines and a resulting hummm problem, the addition of extra grounding points and equipment may exaserbate the problem, just as the healthy grounds inprove a radio receiver reception, healthy grounds on your audio system may make those long audio lines work more like your radio antenna and actually increase the hummmmm mmmmm mmm problem.)
Haven't had a chance to move everything around yet, and to be honest having a long run of component cables is going to look unsightly, and cost alot and I cannot afford it at present. There's also JUST as much chance of them picking up video interference through the cables as there curently is with the (shielded) audio cable.
As I said before, if I unearth the projector, the hum completely disappears... but I then get a shock through the audio cable RCA earth sleeve!
I am now going to try everything running through my passive pre-amp, to get rid of the earthing loop imposed by the Quad 34 pre-amp/Projector (they are the only two items earthed in this setup). If this is then OK and no shocks through the connectors I'll have to look into adding a disconnecting network inside the Quad 34.
I am still puzzled that I could receive a shock through the barrel of an RCA connector though, and one that left me with quite a tingle for about an hour afterwards.
Sintacto: all loads are well within the PSU distribution blocks rating - no power hungry monsters in my setup at all except the projector I guess. Everything working perfectly before in my old flat using exactly the same setup and cables as mentioned at the beginning. Only difference is the house wiring/earthing of course ;-)
I also used the setup here successfully at Christmas - but looking back that was without the Quad 34 pre-amp at the time, so the projector would have been the only earthed appliance.
I have a 'sick of technology' headache now - off for a medicinal beer ;-)
Thanks for the help guys I'm sure it'll be sorted soon.
- John
As I said before, if I unearth the projector, the hum completely disappears... but I then get a shock through the audio cable RCA earth sleeve!
I am now going to try everything running through my passive pre-amp, to get rid of the earthing loop imposed by the Quad 34 pre-amp/Projector (they are the only two items earthed in this setup). If this is then OK and no shocks through the connectors I'll have to look into adding a disconnecting network inside the Quad 34.
I am still puzzled that I could receive a shock through the barrel of an RCA connector though, and one that left me with quite a tingle for about an hour afterwards.
Sintacto: all loads are well within the PSU distribution blocks rating - no power hungry monsters in my setup at all except the projector I guess. Everything working perfectly before in my old flat using exactly the same setup and cables as mentioned at the beginning. Only difference is the house wiring/earthing of course ;-)
I also used the setup here successfully at Christmas - but looking back that was without the Quad 34 pre-amp at the time, so the projector would have been the only earthed appliance.
I have a 'sick of technology' headache now - off for a medicinal beer ;-)
Thanks for the help guys I'm sure it'll be sorted soon.
- John
Moving to the passive pre solved the problem 😎
I'll look into adding a disconnecting network into the Quad 34 now. Due to the fact I'm currently living at my parents place for the next 4-5 months I can't really have mains cables running across the floor so I cannot really rearrange anything as fas as power bars are concerned.
The passive will serve as a good interim measure until I sort out the Quad.
Thanks for your help
- John
I'll look into adding a disconnecting network into the Quad 34 now. Due to the fact I'm currently living at my parents place for the next 4-5 months I can't really have mains cables running across the floor so I cannot really rearrange anything as fas as power bars are concerned.
The passive will serve as a good interim measure until I sort out the Quad.
Thanks for your help
- John
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