Technical Discussion
Rollerblock Jr. uses two cups of similar sphericity, positioned in opposition to each other, with a single ball in between. This "double stack" design was invented and first described by Symposium in our original patent on the Rollerblock, which was filed in 1997 and predates all descriptions of similar "DIY" ("Do It Yourself") devices by several years. The use of a cup, as opposed to a flat surface race, has several advantages when operated without external force fields to damp ball motion (Symposium has since obtained a patent for magnetic bearing bias and stabilization; at present, this technology is employed in the Symposium Isis Rack. For a further technical discussion of the theory behind ball bearing isolation devices, please click here.
Materials Choices and Mechanical Drainage
The material used in the Rollerblock body is critical to non-resonant, neutral performance: Rollerblock Jr.'s robust aircraft alloy construction resists inherent resonance and also transmits energy through itself and out of the component to mechanical "ground" (in other words, the support surface), for best sonic results. Aluminum alloy is chosen for a specific reason: it is better as a coupling medium than brass, steels, or other materials because of its superior mechanical transmission speed which is bettered in nature only by two other metals, silver and copper; however, aircraft aluminum's excellent machinability, strength, hardness, general resistance to corrosion and reasonable cost make it the best choice.
Similarly, listening tests in different systems with various components confirmed that Tungsten Carbide was the best ball bearing material. While many might assume that this is due to Tungsten Carbide's extreme hardness, Tungsten Carbide's excellent mechanical transmission qualities, which are close to aluminum, make it a better "match" to aluminum alloy and thus a better choice than ceramic balls (which have slightly greater hardness but inferior transmission characteristics) for preserving mechanical transmissivity through the entire Rollerblock structure, a primary design consideration.
NEW! HDSE Version
New for 2009: Rollerblock JR HDSE, a high-performance Rollerblock Jr. edition designed expressly for extremely heavy loudspeakers and components. Please click here for detailed information.
Our Guarantee
As with all Symposium products, Rollerblock Jr. is made in the USA. We're very proud of its unmatched quality and precision, as well as its rock-solid and simple-to-use design. If dynamic, engaging, and musically truthful performance is the keynote of your goal in an audio or home theater system, we are confident that you will find that Rollerblock Jr. will outperform devices at several times its price, and "open" up your existing system - or the system you will own years from now - to a new and greater level of enjoyment. If not, we will refund your money - it's as simple as that.