Computer Audio Design Ground Control-Reference grounding box

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Computer Audio Design Ground Control-Reference
Computer Audio Design Ground Control-Reference grounding box

When it comes to audio, it seems to be hard to get majority agreement on anything, but the one exception to that rule is the broad concept that less is (generally speaking) more. But even here you can run into trouble once you start drilling down as far as cause and effect. Just take system grounding as an example: less noise – definitely good: the proliferation of separate ground boxes? Suddenly, customers are not so sure – especially once they start to factor cost into the equation… 

Not so long ago, system grounding was the brave new frontier, virgin territory for system improvement. Despite the established efficacy (and minimal cost) of a dedicated AC line and parallel clean ground to feed your audio system, remarkably few audiophiles, customers with many thousands of hard-earned pounds invested in hardware, had seriously trodden this path. It took the likes of Tripoint and Entreq to attract serious attention, something they achieved by producing large boxes of ‘ground’ with even larger price tags. If Entreq’s homely, wooden crates looked expensive, they were an absolute bargain compared to the $25K price-tag attached to Tripoint’s Troy Signature, the starting point in a range that tops out at around twice that! Not surprisingly, given the extreme pricing but also clearly audible benefits, it wasn’t long before more affordable, second generation ground boxes started to appear in the shape of the CAD Ground Controls and Nordost Q-Kores. In fairness to Entreq, they’d always produced smaller, more affordable units, but they never came close to the performance of their large, Tellus units – whereas the CAD and Nordost boxes did. 

Given CAD’s dedication to USB and network file replay, their natural fascination with things digital is understandable, the impact of their GC1 and larger GC3 on digital system performance entirely understandable. But even so, the arrival of the £20,500 Ground Control-Reference still came as quite a shock, a passive ground solution that costs considerably more than CAD’s server and DAC put together! And that was before I tried to shift the thing… At 50kg the GC-R’s doesn’t just look solid, it might as well be solid. That weight is down to two things: the sandwich of man-made materials inside and the substantial resin-mineral casework. The internal sandwich features the same ingredients as the other GCs, but the precise proportions vary between the different models. What they all do is absorb serious quantities of noise, particularly high frequency noise, converting it to heat. Think the same stuff you’d find in the wings of a stealth fighter and you’ll be somewhere close. The problem with the mixed materials is that they weigh a lot. The acrylic casework on the GC1 can just about cope, but it needs to be doubled up for the GC3 and, once you get enough to build a GC-R, that weight becomes a real problem – hence the substantial casework. Built from Krion, a product not unlike Corian, it is strong enough and non-metallic but also heavy, although in this case the added mass allows the GC-R to sink vibrational energy even more effectively than its acrylic-clad siblings. The cabinet material at least opens up a choice of colours, although you’ll need to get a quote for that flip-flop purple you’ve always fancied. But there’s no escaping the brutal reality that the end result leaves you with a serious logistical challenge to go with that peripheral mechanical advantage. All of which invites several questions – not the least of which is who in their right mind would drop this kind of dosh on a facility that theory suggests can be achieved with a bit of wire and a 13A plug?

The premise behind the GC-R (and all the other high-zoot grounding boxes) is that they provide a separate, clean ground for the system’s signal bus, independent of and in addition to the (essential) AC ground – although they can also be connected to the star-ground of an AC distribution block. That they work is, frankly, beyond dispute if you actually bother to listen to them. How well they work will depend on the system and the situation. Given the £20K ticket on the GC-R it seems fair to assume that it will be used with equipment of commensurate cost and, in many cases that will include multi-box digital replay rigs. It will also include systems where the owner hasn’t or can’t institute a separate, parallel AC ground. So the real questions posed by the GC-R are not, “Does it work?” – it does, spectacularly well – but should it be viewed as an addition to a separate AC ground, a substitute for one – or both? And related to that, is it a partial or total system solution?

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