Agree completely.
If you are having problems with a ground loop, use an isolation transformer.
If you don't want to do that use a battery to power your system.
Maybe you should look into your local building code, and see if your landlords are in violation of renting a property that doesn't meet code. The fines will eventually make them fix the wiring where you live.
Other than that you could always move.
Some things to bear in mind:
a) Mains wiring does not have a "positive".
b) Filter capacitors do not have a "positive".
c) AC filters are not "digital".
d) You can't change the frequency of the mains with a filter.
e) Fiddling with mains wiring can be extremely dangerous, especially if you don't know what you're doing.
a) Mains wiring does not have a "positive".
b) Filter capacitors do not have a "positive".
c) AC filters are not "digital".
d) You can't change the frequency of the mains with a filter.
e) Fiddling with mains wiring can be extremely dangerous, especially if you don't know what you're doing.
Some things to bear in mind:
a) Mains wiring does not have a "positive".
b) Filter capacitors do not have a "positive".
c) AC filters are not "digital".
d) You can't change the frequency of the mains with a filter.
e) Fiddling with mains wiring can be extremely dangerous, especially if you don't know what you're doing.
Ok so maybe I am not concise but...
A) Mains wiring line is for all intensive purposes in thinking about this circuit, a positive because it is the attractor in this case due to the fact that the other two, neutral and ground, are the supplies.
B) Filter capacitors are non-polar. They do however have one side connected to line and one to neutral. I am obviously referring to one or the other.
C) AC filtration on neutral to ground primarily, and perhaps only, seems to have a positive affect on digital equipment. It is a filter for digital equipment.
D) Good now I know for sure.
E) If it was not dangerous would it not be worth doing at all
. Besides I have no fear of the dangerous of AC. I have been making stuff for years, dealt with plenty of wiring etc... but clearly as my posts indicate I am not versed in some of the deeper information of electronics nor am I an electrician so terminology can be off.
What is the signal you want to attenuate and feed back onto itself?
If it's noise introduced into your system from a ground loop in your electrical wiring, the way they are dealt with is to get the electrical wiring redone properly, use an isolation transformer, or run off of a battery.
If there is a cheaper way to solve a ground loop from power lines that is as easy to use as the three that have been mentioned multiple times already I'd love to know since I haven't seen them in any instrumentation book I've ever read.
I solved the ground loop by eliminating the earth ground in my power conditioner box.
Inside my amp there is a starground that connects to chassis, so all is as safe as can be without earth. I would not have even the barely working earth ground if it was not for me upgrading the sockets in my apartment so what can you do... I lost a bit of filtration and safety wise I do not get as much comfort. If I can figure out how to overcome the resistance of the earth ground I can add that filtration back in, but currently it seems like a losing battle in my mind so I will think about it another time.
I am trying to find a good editor for making a drawing.
Basically how it would work.
1. Diodes in front of both phase inverters to prevent cancellation pre-capacitors.
2. Phase inverter in parallel with bypass.
3. The bypass's and phase inverters at each end of the capacitors connect to line and neutral.
That is exactly what I want to make now. The capacitors attenuate noise off of the mains, the phase inverters cancel the noise altogether so nothing running in series in your house can experience any of the noise and re-introduction is impossible. The capacitors act like a crossover capacitor for speakers; they only allow certain frequencies through. The only potential flaw could be a loud diode but I could just buy some fancy ones for a few bucks instead of 30 cents.
Inside my amp there is a starground that connects to chassis, so all is as safe as can be without earth. I would not have even the barely working earth ground if it was not for me upgrading the sockets in my apartment so what can you do... I lost a bit of filtration and safety wise I do not get as much comfort. If I can figure out how to overcome the resistance of the earth ground I can add that filtration back in, but currently it seems like a losing battle in my mind so I will think about it another time.
I am trying to find a good editor for making a drawing.
Basically how it would work.
1. Diodes in front of both phase inverters to prevent cancellation pre-capacitors.
2. Phase inverter in parallel with bypass.
3. The bypass's and phase inverters at each end of the capacitors connect to line and neutral.
That is exactly what I want to make now. The capacitors attenuate noise off of the mains, the phase inverters cancel the noise altogether so nothing running in series in your house can experience any of the noise and re-introduction is impossible. The capacitors act like a crossover capacitor for speakers; they only allow certain frequencies through. The only potential flaw could be a loud diode but I could just buy some fancy ones for a few bucks instead of 30 cents.
Inverting a noise signal: first you need a sample of the signal, if you insist on using capacitors you need at least 2 in series and it is easier with 3, you need the appropriate resistive load to get the required phase shift at the specified frequency. You need a small isolation transformer to remove any common mode from the signal, then you need an adjustable attenuator and a mixer to mix it with the appropriate amplifier input.
And to top it off it will only work at one frequency, mains noise contains more than one frequency and it will need adjusting every time the noise level changes. If the noise phase changes due to load changes in the building it fails. Using a DSP phase shift with the appropriate parameters will work better.
So much for a simple solution that is why as smgidcumb mentions instrumentation books do not mention solutions like this and your problem is very common in the instrumentation field, think low level signals in an industrial environment.
And to top it off it will only work at one frequency, mains noise contains more than one frequency and it will need adjusting every time the noise level changes. If the noise phase changes due to load changes in the building it fails. Using a DSP phase shift with the appropriate parameters will work better.
So much for a simple solution that is why as smgidcumb mentions instrumentation books do not mention solutions like this and your problem is very common in the instrumentation field, think low level signals in an industrial environment.
Before you go any further tell us about your system, signal sources and amplifier, how are they connected to the mains? Are there any light dimmers connected?
The poor earth in your apartment is a minor problem with respect to noise, small signal amplifiers operate fine on floating deck power supplies with 100kV common mode voltage on them with proper shielding grounding and isolation. It is not just the amplifier which needs a star ground, all the signal sources connected to it need the same ground point
The poor earth in your apartment is a minor problem with respect to noise, small signal amplifiers operate fine on floating deck power supplies with 100kV common mode voltage on them with proper shielding grounding and isolation. It is not just the amplifier which needs a star ground, all the signal sources connected to it need the same ground point
A non inductive resistor fits that bill, not sure it will solve your problem though
I use an MMF-5.1 turntable into a Hagtech Bugle with PSU from Hagtech. Both hagtechs are upgraded with FM capacitors, panasonic resistors on PSU, kiwami resistors in the Bugle but first set is TF. In the same box is a passive switch for selection of 6 different sources. I have a RCA to mini cable for computer (movies and things, not so much music). Looking into a sony tuner for Christmas.
Then there is a passive volume control, stepped attenuator with dale resistors from ebay.
Amplifier is Peter Daniels 3875 kit that is the premium version. I am using a 25v secondary 350va Avel transformer.
All components go to my power conditioner which has sockets that are separated from each other and different CMC's for different levels of amperage to each socket. From there power goes to the bus bar which filter capacitors are connected between, and bus bar goes to a Neutrik power plug and then to the wall.
Non-inductive resistor:
This is awesome. What I will do is run my bus bars to components in parallel with a larger resistor than the ones I will use to burn off signal that is attenuated at the capacitors. On each side of the capcaitors I will have resistor and a bypass. The bypass on each side will feature a diode so that there will be a non-resistive draw of signal that is met on the other side of the capacitor by the non-inductive resistor and not the bypass because of the diode.
I guess I can forgo the parallel resistor to the bus bars all together if I test my equipment and find that the resistance of it is much higher than any resistors I could use.
I think this will be a big step forward for my power conditioners. The only thing that could be better would be if some company that was going to make some battery bank type power conditioner actually made the cells. I would use mini cells to provide the current for the attenuated information. That way I would not lose the potential across mains for the power to system, but would have zero noise draw on the circuit just pure current. I am going to try and replicate that with a non-inductive resistor but I know it will not be 100%. Two cree diodes and two/three mills resistors ought to work though.
Then there is a passive volume control, stepped attenuator with dale resistors from ebay.
Amplifier is Peter Daniels 3875 kit that is the premium version. I am using a 25v secondary 350va Avel transformer.
All components go to my power conditioner which has sockets that are separated from each other and different CMC's for different levels of amperage to each socket. From there power goes to the bus bar which filter capacitors are connected between, and bus bar goes to a Neutrik power plug and then to the wall.
Non-inductive resistor:
This is awesome. What I will do is run my bus bars to components in parallel with a larger resistor than the ones I will use to burn off signal that is attenuated at the capacitors. On each side of the capcaitors I will have resistor and a bypass. The bypass on each side will feature a diode so that there will be a non-resistive draw of signal that is met on the other side of the capacitor by the non-inductive resistor and not the bypass because of the diode.
I guess I can forgo the parallel resistor to the bus bars all together if I test my equipment and find that the resistance of it is much higher than any resistors I could use.
I think this will be a big step forward for my power conditioners. The only thing that could be better would be if some company that was going to make some battery bank type power conditioner actually made the cells. I would use mini cells to provide the current for the attenuated information. That way I would not lose the potential across mains for the power to system, but would have zero noise draw on the circuit just pure current. I am going to try and replicate that with a non-inductive resistor but I know it will not be 100%. Two cree diodes and two/three mills resistors ought to work though.
I guess the power conditioner has a ground rail? How is the switch box case grounded? how is the attenuator case grounded? is the signal ground isolated from the case ground. Is the PSU inside the amplifier case or separate? How is the turntable low level signal ground handled? I hope you understand where my questions are leading
There is a lot of opportunity in your system for ground loops and noise pickup. Have you tried disconnecting different parts of your system to see if the noise reduces, the computer would be the first one I would disconnect.
There is a lot of opportunity in your system for ground loops and noise pickup. Have you tried disconnecting different parts of your system to see if the noise reduces, the computer would be the first one I would disconnect.
Yes the power conditioner has a ground rail, connected to a ground plat inside the case, which everything is mounted on.
Switch box? My pre-amp? I can not remember at the moment if I connected earth ground to the box or not. If it is then the low level ground from turntable connects at the same spot, which connects to the hole in the bugle board marked for low level ground.
The amplifier is one unit.
The computer is not usually plugged in.
Your questions are somewhat amusing because you think I have a bunch of audible noise. Yes I get a little FM from being near a radio station for some reason. I am wondering if it is the brass cones on the amplifier that need to be isolated from the chassis but I am not sure. LM3875 are known to have a problem with FM when near a station.
Aside from that all the noise left when I disconnected the earth ground going to the not-really-working earth ground in my apartment. I probably have less noise in my system then most systems out there thanks to power conditioning. You have to understand that most noise is not audible in a way you can recognize it, but when it is gone and comes back you will know. That is why I built two power conditioners for the only two people to audition mine. I promise one of them did not think there was noise in his system nor should the price tag let you think there would be.
I am looking for ways to improve and the diodes with non-inductive resistors sounds great.
Switch box? My pre-amp? I can not remember at the moment if I connected earth ground to the box or not. If it is then the low level ground from turntable connects at the same spot, which connects to the hole in the bugle board marked for low level ground.
The amplifier is one unit.
The computer is not usually plugged in.
Your questions are somewhat amusing because you think I have a bunch of audible noise. Yes I get a little FM from being near a radio station for some reason. I am wondering if it is the brass cones on the amplifier that need to be isolated from the chassis but I am not sure. LM3875 are known to have a problem with FM when near a station.
Aside from that all the noise left when I disconnected the earth ground going to the not-really-working earth ground in my apartment. I probably have less noise in my system then most systems out there thanks to power conditioning. You have to understand that most noise is not audible in a way you can recognize it, but when it is gone and comes back you will know. That is why I built two power conditioners for the only two people to audition mine. I promise one of them did not think there was noise in his system nor should the price tag let you think there would be.
I am looking for ways to improve and the diodes with non-inductive resistors sounds great.
The metal chassis creates a Faraday cage to protect the kit from "airborne" interference, but the power cable (and all other cables) act as antennas, which will pick up the RF junk from the air and inject it directly into the system. So airborne interference does in fact enter through the mains cables et all.
DestroyerOS may want to try some snap-on ferrites. They can be surprisingly effective against RF. They should be snapped on as close as possible to the entry point of the cable. The ferrite basically increases the cable's inductance, but only common-mode. Differential mode currents (such as mains AC current) will not be affected since both the supply and return wires are inside the ferrite, so their magnetic fields cancel. Only common-mode signals like airborne RF picked up by all conductors in the cable are affected by the ferrite.
Sorry, yes we are talking about AC.
The diodes are to make sure that the attenuated signal does not draw through the resistor on the side providing signal otherwise it would cancel attenuation. Come to think of it I may need four.
It is true cables can collect RF, no doubt. I might grab some ferrite beads.
I might write confusing stuff but I promise I never do experiments that put myself at risk! All manufacturing (all four unites to date) have been under direct supervision of a veteran electrician.
That did not work when I was using another set of speakers for the same issue.
Peter Daniels has specifically mentioned this as being an issue for some 3875 owners.
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