Suspended animation for audio signals?
By Roy Gregory
As audiophiles have become increasingly aware that building a system – and the performance eventually achieved – depends on more than merely throwing down the necessary cash to take home the latest, most magnificent black (or silver) boxes, we have seen the emergence of a new emphasis on system matching and set up. Suddenly as well as electronics and speakers, system infrastructure – those passive elements that up until now have been little more than necessary add ons – are finally getting their day in the sun, with issues surrounding AC supply, grounding, cable strategy and support receiving the attention they deserve. But even so, there’s a hierarchy of seriousness with which these system elements are treated and currently sucking hind tit is the whole subject of equipment support – despite the existence of excellent support systems from the likes of HRS and Grand Prix Audio and their quickly (in fact, shockingly) demonstrable benefits.
Part of the problem lies in the fact that for years, we’ve misunderstood and misnamed the whole support category, thinking in terms of isolation. Once you appreciate that internally generated energy is at least as significant a threat to the signal passing through hi-fi components as intrusive, external energy, your whole strategy and the resulting benefits are transformed. Look at today’s best support products and all of them include a coupling solution designed to sink energy out of the supported components and into the dispersive structure of the rack itself. Mechanical grounding of electronics has become the de facto standard approach, whether you use Apex footers, Nimbus pucks, Sort Kones or Stillpoints to achieve it. However, like all the best rules, there are exceptions, and it’s one of those I want to discuss here.
Harking back to the old ‘isolation’ model for a moment, several companies over the years have offered suspended racks or platforms to insulate your equipment from outside influence. Over the years, I’ve flirted with the idea of suspended racks, but they have all been quirky and far from practical in use. It’s easy to hear their impact on system noise floor, but it’s also easy to hear their impact on focus and dynamics – and not in a good way. Given that matching the dynamic range of real life is the biggest challenge facing most audio systems, that makes suspended racks a lousy trade-off. However, occasionally circumstances conspire to swing the balance in favour of isolation over mechanical grounding, a situation in which an effective, individual isolation system becomes the preferred solution. Such situations are indeed rare, but there’s one scenario that regularly repeats: the two-box tube pre-amp that separates its signal and power supply chassis. Why? Because the primary sources of internally generated energy (the transformers and power supply caps) are physically isolated from the audio circuits; circuits constructed using active devices (tubes) that are – in some cases critically – prone to external microphony. In this instance, providing a suspension system for the audio chassis can reap a rich dividend in terms of musical performance.
Clever Trevor…
The problem is that when it comes to suspension, one size very definitely doesn’t fit all, which is where Solid Tech’s Discs Of Silence (DOSs) come in. Each DOS comprises a small, flat inner disc and an outer, concentric ring standing around 1”/25mm tall, and the two elements are linked using small coil springs. A thread through the middle of the central disc supports a mushroom-like head, topped with a neoprene disc. Place three or four of the DOSs under your pre-amp chassis and hey presto, it floats free, supported on those sprung, central elements. But this is where things start to get smart. The problem with most suspension systems is that they find it challenging to accommodate differences in the mass and weight distribution of the unit(s) they’re supporting, leaving you with products offset front and back, side and side in a vain attempt to maintain something approaching level. The DOSs tackle this in two distinct ways. Firstly, although they arrive with three springs installed between the outer ring and suspended disc, there are holes provided to accommodate anything up to 12 springs per foot – at which point a set of four DOSs can float up to 175kg at the prescribed 5Hz frequency. A supplied table tells you how many springs to use, and fitting extras is simplicity itself. Secondly, the central mushroom support is itself height adjustable, with a lock nut to ensure its stays put, so once you’ve got the loading on the feet right, levelling the component is also straightforward. The adjustment provided also allows the DOS feet to bypass taller stock feet fitted to some equipment.
- 1
- 2
