AudioPrismís Ground Control:
Another Listenerís Opinion





The boysí night in

On Tuesday evenings, the husband of a couple who summer in a town not far from ours drops by for some listening as his wife attends a life-drawing session. My Tuesday-evening guest holds a PhD in electrical engineering Ė a no-nonsense, measurements-and-numbers kind of guy.

But flexible. His skepticism with respect to audioís weird-science accouterments was earlier eroded by a simple now-itís-on, now-itís-off demonstration of Acoustic Reviveís RR-77, which operates, or so they say, on a principle identified as the Schumann Resonance. Iíve mentioned this product in my Random Noise columns.

The important thing is, he likes good sound and listens with an open mind. Before we settled down, I asked him to look at a statement accompanying AudioPrismís Ground Control. It discusses ground planes in an historical context and segues to the GCís purpose and accomplishments.

My friend didnít get it. The statement wasnít convincing, nor, he thought Ė at least to look at Ė was the Ground Control itself, consisting in the main of a few of inches of copper wire encased in a tiny sock. I donít get it either, but Iím a techno-dummy who knows better than to pass along jargon I donít understand. I listen. Period.


So then. I began with Mingus Big Band Live at Jazz Standard, a nicely recorded, agreeably aggressive CD released in 2010 ( and

But I need to interrupt the narration to mention that Iíd installed an RCA-terminated Ground Control at each of my NuForce mono ampsí RCA inputs, along with another at my Integris CDPís negative RCA output. (I use balanced interconnects.) I also have spade-terminated Ground Controls at the negative binding posts of my Sasha W/Ps, for a total of five GCs.

The interruption continues. Thereís weird science, and then thereís weird science. The Ground Control is the work of EnABLís Bud Purvine, whom AudioPrismís Byron Collett describes as a brilliant designer of transformers and such. Purvine has accumulated patents, an enthusiastic following, and a presence on the Internet I invite you to investigate. I need to return to these fascinating little whatevers.

In the matter of a reliable A/B comparison, itís a lot simpler to pull and reinstate RCA-terminated Ground Controls than to remove and restore the spade-terminated GCs at the Wilsonsí binding posts. For most of us, the memory for other than gross differences in sound is short and unreliable.

To return to our story: the big-band disc and a second demo, a beautifully recorded Haydn string quartet on the TACET label, elicited a comment Iíll not soon forget: ďThis shouldnít be happening.Ē You can imagine the expression that went with this.

But it was happening. My friend was in the sweet spot. As before, standing at my systemís electronic components Ė in other words, behind the speakers and facing the wall Ė even I could hear it: with the ampsí and CDPís Ground Controls removed, the system relinquished a clearly audible slice of liveliness and body. Days before, I heard an improvement on my own when I first installed GCs at the speakersí negative binding posts. There is nothing vague about the benefit to an already excellent system these five Ground Controls deliver.

I like my Tuesday visitorís attitude. His background and assumptions defer, need be, to what he hears. Like Clement Perry (his GC review here), Iím sold on tweaks, but I donít hold all in equal esteem. A few in my system play a pro-forma role. If I removed the speaker-cable lifters, I doubt Iíd hear much of a difference. I figure that they do no harm and perhaps a smidgen of good. And they look sexy.

I hesitate to call the Ground Controls sexy. Like the featherweight RR-77 Ė is there actually anything inside that thing? Ė what they do for a systemís sound flies in the face of their seeming insignificance. The GCs Iíve been using are identified as Reference. The substantial list prices reflect the cost of their XHADOW silver connectors and the tariff we enthusiasts pay for success.

Reference RCA, $149.95 each.

Reference spade, $249.95 / pair.

You can check out the entire line, with prices, banana terminations included, at



























































Luminous Audio