Ground Control GC1.1 Earthing Device from CAD | REVIEW

ground control

I’ve already shared the story of how I met the folks at Computer Audio Design (CAD) once or twice on these pages, and how I wound up reviewing their Ground Control GC1.1 earthing device. But here’s a quick recap.

I didn’t know much about this UK-based company because, quite frankly, I’ve only been recently exposed to the new digital world where CD players and digital downloads have been mostly replaced with streamer and servers and stand-alone DACs. It took a while for me to catch the fever, in other words, and the words “computer” and “audio” took their sweet time in appealing to me. Not to be dismissive, but the only reason why I walked into that CAD room at the 2023 Florida International Audio Festival was simply because it was there. Talk about serendipity.

Words and Photos by Marc Phillips

I had just met PTA writer Matthew Partrick for the first time in person at the 2023 FLAX and I handed him the manual, How to Cover High-End Audio Shows for PTA, ninth edition. We were standing in front of the CAD and EgglestonWorks room, so I suggested we go in for a quick look. I pointed out a few things about the room, and we headed back out into the corridor to discuss strategy.

We both decided that he had all the info he needed. “You know,” I said, looking back toward the open door of the CAD room, “that room sounded great. Why don’t you start there?” He agreed, enthusiastically, and I left him to his own devices for the rest of the show. Meanwhile, Isabel Whitley of Computer Audio Design had seen my name tag back when I was in the room, and she had been preparing to give me the grand tour. I imagine she was a little disappointed when Matthew walked back in without me, but nevertheless he had a wonderful and productive visit.

A couple of months later, just before the Munich show, I received an email from Isabel personally inviting me to the CAD room. I felt a little bad for not speaking with her back in Tampa, so I made sure to stop by. We had a good laugh about the FLAX incident.

computer audio design

Just a few months later, Isabel and her husband Scott Berry, CAD’s founder and engineer, were at my home setting up equipment and giving me the scoop on the Computer Audio Design Ground Control GC1.1 they brought–as well as the CAD 1543 DAC. The Ground Control GC1.1, as you’ve already guessed, is a grounding device for high-end audio systems. (In the UK, they prefer earthing device.) The $2,250 GC1.1 is a compact, somewhat heavy (just under 5 kg) box with just two grounding ports designed for banana plugs on the back. CAD’s grounding wires, which cost $350 each, have one end designed to fit that port, and the other end matched with any type of connection you desire. We’ll go into that in a bit.

Isabel and Scott also brought their vaunted 1543 DAC MKII ($15,000 USD) for me to try, but with one condition. The 1543 DAC MKIII was close to being finished, and I’d be one of the first to test it, so there was no point in reviewing this demo sample. The real reason they brought the 1543 was because I asked them to–that was the turbulent period in the summer when I had review pieces such as the Antipodes Oladra music server and the Innuos PULSAR network streamer on deck, and I had no DAC in my kingdom at the time. CAD needed the 1543 back in a couple of weeks, but that was okay since the Merason DAC-1 Mk. 2 arrived shortly afterward.

Through all this shuffling over the last few months, the Computer Audio Design Ground Control GC1.1 has stayed put in my system(s). It’s small and it’s low-key and you forget it’s there, unlike other grounding devices with brightly colored grounding wires that tend to distract from the gorgeous gear on your equipment rack. That’s another way of saying that the Ground Control is one of the easiest and most compact (i.e. unmessy) earthing solutions I’ve discovered in high-end audio.

marc phillips system

Inside the Computer Audio Design Ground Control GC1.1

If you haven’t received the memo, the age of wireless technology and digital audio has prompted the need for new grounding strategies in high-end audio. For many audiophiles, an effective grounding strategy involved relying on individual manufacturers to properly ground each component. “Haven’t we already figured out grounding?” many have asked, and until recently I was once one of them. But a properly designed earthing product will lower the noise floor significantly, especially when we have so many modern devices saturating our homes with RF and noise and other very bad things. A grounding product such as the Computer Audio Design Ground Control GC 1.1 has become mandatory in 21st century high-end audio if you want to take your system to the next level of performance. I’m not trying to sell you anything, I’m just stating 21st century facts.

So far, I’ve reviewed a number of earthing devices from companies such as Nordost, Atlas, AudioQuest and more. They all work, to varying degrees. In fact, many manufacturers have come up with complicated ways to ground a system, leading me to once believe that the more grounding there is in a system, the more the noise floor will be reduced. (That’s how a grounding device can create an instant rat’s nest behind your equipment rack, by the way.) Some manufacturers, such as Atlas and Ansuz, use star-grounding inside of a power conditioner, filter or power strip, which keeps things neat and tidy. These products can also be quite expensive.

Scott Berry explained to me that while grounding devices are usually effective, few address how to pair components for the best results. Since the CAD Ground Control GC-1.1 only has two ports per box, it’s important to pair those two grounding points in the right combinations. You can use just one of the ports, of course–Isabel told me that many clients use just one Ground Control per component. But Isabel also informed me that these are the three most common pairings: a computer-based server via an unused USB connection; a DAC/CD player via an unused digital connection and also to the pre-amplifier/integrated amplifier via an unused RCA or XLR input; and a phono pre-amplifier via the tone-arm ground connection.

“CAD feels the best results comes when you connect either Earth (the third pin on your wall plug, and normally connected to the conductive chassis of audio equipment) or Signal Ground (the negative side of an RCA/XLR) to a Ground Control. Connecting both Earth and Signal Ground to a GC1.1 Ground Control will typically not give the very best results.

“Most computer-based servers connect Signal Ground directly to the chassis to help reduce high frequency emissions and pass regulations. Whereas most audio components do not connect Signal Ground directly to the chassis. Also, most USB connected DACs now days have what’s called Galvanic Isolation – this stops current flowing from the server into the USB interface of the DAC. This helps reduce unwanted noise from your computer/server entering your sensitive DAC.”

ground control

For those reasons you shouldn’t pair a DAC and a server to the same Ground Control–it will work, but it won’t be optimal. Scott suggested connecting just the server to a GC1.1 (and nothing else) via an unused USB A Port gives the best results.

Scott also gave me another useful tip:

“If you want to understand how much high frequency noise your Earth in your home has attach a Ground Control to your power distribution strip or power conditioner and nothing else. If you hear a nice improvement in sound quality, you know that your Earth lines have some noise, and it may be worth using a Ground Control just on Earth. Most homes that are in a densely populated urban environment will have more noise on Earth compared to a remote home out in the woods.”

(Interesting…since I now live in a remote home out in the woods.)

“If a Ground Control does not offer much sound quality improvement when connected to Earth this means there just isn’t much noise there. In this case you want to concentrate on the audio components that produce most high frequency noise (computer-based servers, CD players, DACs) or to components that are sensitive to high frequency noise (phono preamplifiers).”

Since the CAD grounding wires have so many terminal options, you can choose a grounding wire with an RCA connection, or an XLR, or a USB, or whatever else you got. (Other connectors include coax, spades, banana plugs, ethernet and more.) I know what you’re thinking–what if I want to ground my system at more than two points? That’s where the compact size comes into play. You will have to buy a new Ground Control GC1.1 for every two additional components. (I have seen big audio systems at high-end audio shows where several GCs are lined up in a row.) Your other option is to check out the much larger Computer Audio Design GC3.1, which weighs in at 16 kg, and the new GC-R (which stands for Reference), which weighs in at a massive 50 kg and has ten grounding jacks.

computer audio design usb

CAD 1543 MKII DAC and USB II-R Cable

Despite the fact that I only had the CAD 1543 MKII DAC on hand for a couple of weeks, it made a big impression. I don’t want to dilute my impressions down to the fact that this is the most expensive DAC I’ve used in my system, but I had the sense that I was in the company of a very refined, high-performance product that instantly made my life easier.

The 1543 MKII is stripped down to the essentials–there is one USB port, and two unbalanced RCA outputs. That’s it. There’s an important reason for this:

“The CAD 1543 MKII DAC has used as few components as possible in the signal path. For that reason we do not offer additional inputs or outputs. The digital signals travel less than 1 cm from the USB board to the DAC chips. Due to there being only one input the digital signals do not pass through any switches. Digital signals run at extremely high frequency (MHz) and sound quality can be significantly reduced when switches are used in the digital domain.”

The CAD USB II-R cable (starting at $1,500 for a 1.1 meter length), on the other hand, has stayed in my listening room for quite a while. It’s gotten to the point where whenever I need a USB cable in the main system, I automatically reach for the CAD. That’s not exactly a description of the Scientific Method, I know, but I have noticed this intuition before, especially with cables. You don’t think as much about the specific advantages a wire brings to a system until you work without it and notice things don’t quite sound their best. It comes down to this: my most satisfying digital results, with high-end digital products such as the Innuos Pulsar and the Antipodes Oladra, occurred when I used the CAD.

Both the CAD 1543 MKII DAC and the USB II-R cables combined to create that same no-nonsense, straightforward approach to digital audio. The sound quality of the two can best be described as effortless. The streamlined design is very true to the essence of “getting out of the way of the music,” a quality that is often problematic to DACs. I’ve often had the impression that some digital-to-analog converters let you hear all the work they’re performing behind the scenes. The best digital audio I’ve tested is the opposite–digital suddenly takes on the relaxed and open quality of the best analog playback.

I’ll go into more depth, of course, when I review the new CAD 1543 MKIII.

cad ground control

Computer Audio Design Set-Up

I listened to Scott Berry’s recommendations about grounding points, so I started off with the Ground Control connected to both the AudioQuest Niagara 3000 and the most obvious choice, the grounding hub on the back of the Music Hall Stealth turntable. I left the first grounding wire in its spot while I tried moving the wire from the turntable to the various phono stages I used, including the inboard MM phono stage from the Naim NAIT 50 integrated amplifier and my reference Allnic Audio H-6500 phono preamplifier. I also used the Ground Control with my reference Pear Audio Blue Kid Howard turntable with the Cormet2 arm and the ZYX Ultimate Airy X moving-coil cartridge.

From there, I switched to digital–the second grounding wire was used with everything from the Antipodes Oladra music server, the Innuos Pulsar music streamer, the Matrix Audio Element X2 Pure streamer/DAC and the Merason DAC-1 Mk. 2. I also used the Ground Control with the CAD 1543 DAC, obviously.

I put the Ground Control on a mission with my headphone rig. As I mentioned in the review of the Audion Silver Night headphone amp, which uses 300B tubes, and the highly resolving ZMF Caldera headphones, I could hear every little detail. But I also detected some tube rush, perhaps a touch of microphonics, something that seemed a little odd after listening to my more-than-properly grounded main two-channel system. I’ll skip to the chase–the Ground Control cleaned up the sound and I was lounging in headphone heaven for the rest of the Audion’s stay.

Finally, here’s the most obvious example of how effective this earthing device is. While converting my tabletop headphone rig into a tabletop turntable testing bench for the Stealth, I had to chase a ground hum. I checked everything twice, and then I remembered that the CAD Ground Control was over yonder on the other side of the room. One grounding wire from the Ground Control to the back of the Stealth and the hum had vanished. Night and day. I know, any type of ground hum or noise should be thoroughly investigated because something might be wrong–but the CAD stopped that infernal racket in the meantime.

cad 1543

Computer Audio Design Ground Control Sound

I’ve already spent too much time considering the sonic benefits of proper grounding: it’s not a matter eliminating tube rush and microphonics as with the Audion, but rather the illusion of more music coming through than ever before. Transients are sharper and quicker. Dynamics improve, because there is no longer a high noise floor that obscures the little and precious things that happen in most recordings. The Ground Control quickly accomplished all that.

One thing to mention about grounding devices, along with some power conditioners, is that it’s tricky to do quick A/B comparisons because it takes a few seconds for everything to settle–especially when it comes to energizing capacitors. I remember attending a Stromtank power conditioner demo where I was asked to count to seven before listening critically for the differences. It’s tougher than it sounds–you have to be patient. On the other hand, the CAD is a passive device, so it’s easy to perform comparisons on the fly.

If you know what to listen for, you’ll hear it when it happens. The music, for lack of a better descriptor, leaps out at you a little bit. At the same time, those black silences settle in with a sense of authority, changing the perspective somewhat. But I think the better approach is to listen to your system with the Ground Control in place for a while. Play a bunch of music. Let everything “settle in.” Then take the CAD out of your system.

If you’re me, you’ll experience an instant change in your mood for the worst. A high noise floor will make music sound more ordinary–flatter, lifeless and downright dull. Your ears will adjust to the noise after a spell, but you’ll always know that your system sounded airier, more natural and more quiet with proper earthing, and you’ll be mad at yourself for not trying out a high-quality grounding box like the Ground Control until now.

cad ground control

Listening Sessions

WARNING: further discussion of Tool’s “Chocolate Chip Trip” ahead.

Okay, now that the terminally uncool have left the building, I’ll explain why I’m so enamored with this drum solo from the world’s greatest living drummer, Danny Carey. CCT is a stupendous track, with incredible dynamics that will startle you, imaging that might trigger an acid flashback, and a soundstage that will figuratively knock down the walls of any listening room, no matter the size. But there’s another level to this track that can only be revealed with the most resolving systems. That higher level, of course, is a man named Danny Carey.

With the Ground Control GC1.1 in place, I heard more physical cues from Carey’s preternatural reach. I heard the sounds of those long arms reaching every corner of that huge kit with surprisingly little effort. The CAD captured so many of those astounding aural cues that prove, to a certain extent, that CCT isn’t nearly as much of a studio creation as it sounds. (I’ve mentioned this before, but it’s easy to believe that Carey gets a lot of assistance from studio gadgets until you actually watch some of Tool’s concert videos and witness that this drummer can replicate the same sounds live.)

Okay, okay–I’m tired of talking about CCT, too. But that was the first track I heard with the CAD in place, and my heart was still pounding from the beginning to the end of the track on every subsequent listen.

I’ve become a little obsessed over the new UHQR pressing of Steely Dan’s Aja, and I’m spending too much time focusing on the title track. (Before the UHQR, “Deacon Blues” was THE longtime fave from this album.) Like many Steely Dan fans, “Aja” is a masterpiece for featuring some of the greatest drum work of all time from Steve Gadd. (What, more drummers?) But there are two points on the song where a quick little figure on synthesizer, low and surreptitious, emerges from the depths of the mix. I never noticed it until recently, when the quality of my hi-fi jumped up several notches. Plus, the arrival of the Analogue Productions UHQR really fleshes out those small musical moments to a greater degree than before.

With some systems, that synthesizer is barely audible. With the CAD in place, I heard more than just a few notes from a keyboard. I realized that these two points in the song served as punctuation–“Aja” is an epic song, with many shifts in tone, and that synthesizer lick organizes the entire journey and reminds you exactly where you are within the structure of this sprawling track.

Finally, I believe that my highly favorable impression of Chet Baker’s Blue Room from Jazz Detective was due, in part, to the presence of the CAD Ground Control GC1.1 in my system at the time. Blue Room is one of those reissues of a long-lost recording, but it’s one where the sound quality is very, very good. It’s so good, in fact, you might think Chet is still alive and making records in 2024. It helps that this is already such a fine pressing with little surface noise, but the CAD enhanced this recording to the point where it transcended the idea of a historical recording that is merely intended for posterity.

1943 DAC

Ground Control Conclusions

Here’s a straightforward assessment of the Computer Audio Design Ground Control GC1.1–it spoiled me. I don’t like seeing it go. I will be able to keep it for a while, at least until the new CAD 1543 MKIII DAC comes out. Will I drag my feet with that review? I’m not making any promises, but it’s possible.

Many of the reasons to choose the Ground Control over any other earthing device are based on practical reasons. The GC1.1 is compact, easy to use, and it stays out of the way and lets you enjoy your hi-fi. $2,250, plus $350 for each terminated grounding wire, isn’t cheap, but the CAD is more affordable than many of the grounding devices I’ve tried–and I felt it was just as effective, if not more, at lowering the noise floor. Plus, you can upgrade by buying more Ground Controls, or perhaps move up to the GC3.1 or the GC-R.

Proper earthing isn’t a complicated thing. It’s not a tweak, there’s no snake oil, and everything is based on science that has been around for quite a long time. Audiophiles can look into grounding solutions without worrying that it’s the latest trend in audio that will ultimately pass. Grounding isn’t the latest trend–all those wireless signal producers and computers and routers and ethernet switches are actually the trend, and grounding is the solution.

The Ground Control, however, is a solution that appeals to me–perhaps more than any other grounding device I’ve seen. CAD has shown a tremendous amount of gumption in diving into this technology with such fervor. If you doubt this, try the CAD. It won’t be a tough decision for you to make because you’ll be spoiled, too. Highly recommended.

pta reviewers choice

ground control with cad 1543


marc phillips test bench

ground control

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