In most components the circuit ground is directly connected to the chassis. And the chassis is connected to power cord ground. Pretty sure all common ground amplifiers are set up that way. You would not want to try your RCA trick with a non common ground amp.
So what you are proposing technically not make any difference, but anything goes with audio. According to the books what you are doing should make the system sound worse. You are supposed to ground everything in a component to a single point on the chassis via a "star ground". Grounding to different points is supposed to do bad things to the sound.
I would take a peek inside and make sure the circuit ground is connected to the chassis somewhere. The power cord ground should be connected to the same point. Then even though it goes against conventional wisdom......if your system sounds better go for it.
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In most components the circuit ground is directly connected to the chassis. I believe that is not true. And certainly, IMO, a **good** design will not connect circuit ground and chassis directly together, as it invites ground loop issues. As Erik indicated, many designs have a resistor connected between circuit ground and chassis, and many others go even further in isolating them from each other. I know, for example, that circuit ground and chassis are not connected together in most or all Audio Research, Ayre, and Atma-Sphere designs, among others. Regards, -- Al |
What you are doing is perfectly safe. The outside is ground anyway. Its real easy, with tube gear anyway, to look inside and see the one wire coming from the center of each RCA and going straight to the input selector. Only one wire. Don't take my word for it. Look and see. One wire. That's the pin, that's the signal, that's positive. That's why its insulated, and routed the way it is, away from noisy bits like transformers. That's why they lay them out the way they do.
Notice the outside of each RCA. They are not wired individually. They do not go to the input selector. On many amps they connect to a bus bar. Follow that wire, which notice is not insulated, it will at some point complete the circuit by being connected to ground. They may all come together at one point, I don't know, have only looked into and modded a few so there may be some exceptions.
When there are you can be sure its for sound quality not safety. Mainly the problem is the way electricity works, running a signal through a wire generates a magnetic field around the wire proportional to the signal. While at the same time every magnetic field crossing a wire induces a voltage in that wire proportional to the field. This is how electricity is generated, be it in a Koetsu cartridge or Hoover Dam, and this is how transformers work too. And antennas. Same deal.
So if you're hearing an improvement that kind of makes sense. What you're doing is providing a more direct route to ground taking that one small part of the problem out of the amp. A little less is a little less and if you hear it you hear it.
Count yourself lucky. The ground loop guys are right. Only thing they're missing is its a crap shoot. One guy does everything right, winds up with hum and hunting down a ground loop anyway. Another guy (that would be you) deliberately wires extra grounds which one would think ought to hum like crazy, and instead it actually sounds better. Go figure.
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I use these from Gutwire: http://gutwire.com/?page_id=1334They connect via your RCA, XLR, spade or Pin safely to an outlet. I've had mine for over a year and no problems whatsoever. All the best, Nonoise |
The following thread will be of interest: https://forum.audiogon.com/discussions/a-new-ground-benefits-of-introducing-the-synergistic-research-active Some excerpts: Atmasphere 6-27-2017
I did a survey of a number of grounding systems by interviewing the owners and having them do a few tests (as best as I can make out, these were similar to the SR, but none of them were SR units).
What I found was that in audio systems where a grounding system made an improvement, universally there were also bugs in the way that the associated audio equipment was grounded, which is why the grounding boxes were helping.
Just my opinion of course, but if the manufacturers of the various products (amps, preamps and the like) in those audio systems were to fix the bugs in their products, the result would be even better and at worst just as good as the (IMO rather expensive) grounding system add-ons.
My conclusion was that if a grounding box was helping, that was an indication that the associated equipment had design flaws in their grounding implementation. Atmasphere 6-28-2017
All it takes is one component to short out the grounding scheme on the other equipment.
How it works is, the chassis of the equipment should be grounded to the ground pin of the AC cord which in turn is grounded by the house wiring. There is no current on this connection....
... The circuit ground of the amplifier, preamp or whatever is **not** connected to the chassis in a proper setup but is instead ’floated’ at ground potential by a simple circuit which might simply be a resistor or resistor/diode arrangement. In this way ground loops between equipment are prevented and the chassis is allowed to act as a shield while not also acting as a ground return.
If only one piece in the system has the circuit and chassis be the same thing, then its connection to the rest of the system will compromise the grounding of the rest of the system. Now you have to do something about it and that is what these grounding block thingys do- at a tremendous price though, as a better solution would be to simply have the offending piece repaired by the manufacturer. Almarg 6-28-2017
Ralph, thanks. That all makes sense from a technical standpoint, as far as I am concerned. Question: Could similar adverse effects occur to an audible degree if rather than circuit ground and chassis ground/AC safety ground being connected directly together in one or more of the components in a system, they are instead connected together through a resistor whose value is simply too low? For example, I’ve seen in some ARC designs that resistors as low as 10 ohms are used for that purpose. Atmasphere 6-28-2017
Hello Al,
The resistor is there to prevent ground currents and often 10 ohms is enough to do the job, just as you see in the old Dynaco gear.
I like a little more myself, and its not a bad idea to place some high current diodes in opposite directions in parallel with the resistor. In this way if a component is damaged and places the AC line on the chassis, a fuse will blow rather than just cooking the resistor.
I’ve not played with the resistor value to see what effect it has, but it stands to reason that a value too low mitigates its use and not in a good way :) Atmasphere 7-5-2017
If you have a DVM there is a simple measurement that will tell you if the amp/preamp/whatever is properly grounded.
With the unit unplugged and out of the system, the DVM set to the Ohms scale:
The center pin of the IEC connection (or ground pin of the AC cord) should measure a short to the chassis; IOW about 0.5 ohms or less.
If the ground of the audio input connection measures the same then you have a problem. If it seems to measure significantly higher than things are good.
If you have no connection between the chassis and the ground pin of the AC cord then the equipment can be considered dangerous and will not meet UL standards nor EU Directives (CE mark).
And note especially the second sentence quoted from the following post! Folkfreak 10-29-2017
The [Synergistic Research] active ground block has active components inside as well as a ground connection.
... even passive ground solutions give results, consider for example the Entreq units which have no connection to the AC safety ground at all but still produce the same type of results. ted_d (Ted Denney of Synergistic Research) 5-1-2019
The Active Ground Block SE has an Active Electromagnetic Cell similar to what is found in our PowerCell line conditioners, the non SE version does not. This (the Active EM Cell) filters high frequency noise out of ground which is significant....
... NEVER EVER plug the Active Ground Bock into anything but the wall. Do NOT plug it into a line conditioner or anything but a wall outlet otherwise you will introduce impedance and crosstalk contamination and this seriously diminishes sound quality.
Regards, -- Al |
