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A New Ground -- Benefits of introducing the Synergistic Research Active Ground Block SE

Dedicated ground solutions are not a novel idea but over the past year it seems everyone has been coming out with their version. For a few months I’ve been thinking about introducing one to my system and had considered Entreq, Telos, Nordost and others. Although I have a bunch of Synergistic Research (SR) kit I had dismissed their older basic ground block as too rinky dink -- however when I heard about the new Active Ground Blocks I thought that could be the way to go. The Active Ground blocks are smallish devices with a mains connection and a plethora of outlets for grounding cables to every component. They incorporate a range of the latest SR UEF tweaks
http://www.synergisticresearch.com/isolation/ground-isolation/active-ground-block-se/

While the blocks alone are quite expensive ($2995) you will also need to lay out for connections to all of your components -- ideally the HD links. In my case as I have two distinct zones in my system I needed two ground blocks and 13 links -- quite an outlay

Question is is it worthwhile? Most certainly yes. The impact of implementing a full grounding solution in my system was one of the most profound changes I’ve experienced. It’s not a change that can be described in the usual audiophile terms of dynamics, frequency response, transparency etc. Instead it’s a shift in the wholeness, the verisimilitude, the gestalt of what you are hearing. Probably this is most obvious in a couple of places. Firstly is in background washes of sound (e.g. classic synth backings, or massed strings, or the whoosh that opens "Private Investigations") -- which now take on a scale, texture and clarity that had previously been completely masked. Secondly in vocals where a whole level of shading, nuance, breathwork, and subtly inflections are now audible. This is not simply more "detail" or a "reduction in the noise floor" it’s as if things which you did not know previously existed are suddenly there, as they had been all along

The effect is enhanced the more things you ground -- obviously all active components but even stands (my GPA stands are conductive so I connect a basic ground link to the bare metal inside the stand posts -- the surface metal is varnished and non conductive).

While I obviously can recommend the SR products I imagine any ground solution will bring similar benefits and would strongly suggest that anyone with a high resolution system explore some form of ground solution

ps For those in the now the music to accompany this review is A New Ground

128x128folkfreak

Showing 7 responses by atmasphere

atmasphere's avatar
atmasphere
7,068 posts
 
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's avatar
atmasphere
7,068 posts
 
@folkfreak 

 if that was the case then why would grounding the stands after everything else had already been grounded to the SR box make an improvement? And why would changing the cables used for the grounds make an improvement? I use equipment from a wide range of manufacturers so can't believe they all got it wrong out of the gate... I think there's more going on here than your hypothesis
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, in contrast to what is claimed by SR's website page on their grounding block.

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.
atmasphere's avatar
atmasphere
7,068 posts
 
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's avatar
atmasphere
7,068 posts
 
@folkfreak 

Sorry Ralph -- you're dodging my question. If I accept your argument then installing the grounding box fixes all of the issues that the designers of the original equipment caused by (as you hypothesize) grounding the chassis of some but of kit somewhere along the line

Ok with this fixed why the hell should it then matter that I ground a passive piece of metal and carbon fibre (the stand) -- or is it equally valid that these huge bits of conductive material are picking up god knows what nasties and the ground path is a way of getting this crap out of the system?

Actually I'm not dodging anything. However FWIW I'm not making sense out of the second sentence of your first paragraph here and I'm happy to address it if you can clarify.

Regarding the latter paragraph: FWIW some years back at my house I found it a good idea to ground my equipment stand (Sound Anchors custom stand) as floating it seemed to cause a little hum in the phono. But oddly(? perhaps not) as we improved the grounding scheme in our equipment over the years, for some reason grounding the equipment stand no longer has any effect.  I know I don't have a lot of RFI in my location, so I suspect that grounding a metal stand in a noisy environment is not a bad idea. But all that is needed for that is a bit of wire.

Note also that all depends on the house wiring being correct. In that regard the green wire on the AC outlet is the ground wire... and that's the one that is tied to house ground. Now the neutral (white) wire is also tied to that point, but the neutral carries current while the ground wire does not. So the ground wire will not carry any significant current if the audio equipment is properly grounded. This will prove to be an effective sink for RF noise and the like which is always present in some form.


atmasphere's avatar
atmasphere
7,068 posts
 
@folkfreak

No. The ground of the arm is independent of the audio signal.

In fact what is happening is that the tone arm is a balanced source which in most cases is being operated single-ended. That's why you wind up with that grounding wire which other single-ended sources don't seem to need.

At any rate the ground wire is independent of what is the signal ground in the preamp.
atmasphere's avatar
atmasphere
7,068 posts
 
@whart 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).
atmasphere's avatar
atmasphere
7,068 posts
 
@whart
I know it is grounded now, but will hum unless I lift the ground. I do have a decent meter and will poke around without opening up the units.
That suggests that the audio and chassis are the same thing FWIW...

@lowrider57
Two questions; will all components then have the same ground potential?
Star-grounding a component is an improved grounding technique, but does it change the ground potential from a traditional component grounding design as stated above?
1: They better!
2: It better not! The reason is there should be no current in the ground connection.

@whart
Measuring at the RCA input to the amp, with everything, including speaker cable, disconnected, the shield or collar side of the RCA jumped around radically, nothing nearly as low at the ground pin, but high voltages, lower voltages- and no OL type reading on the meter suggesting it is "off scale." Why is that so?
Sounds like an impedance that might involve an inductor.

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