AOM Logo June 1998


A Diamond in the Rough
Black Diamond Racing's "Round Things" Record Clamp


Andrew Chasin

In a scant few years, D.J. Casser's Black Diamond Racing has risen from relative obscurity to the upper echelon of audio tweakdom. Having almost singularly pioneered the use of carbon fiber for damping and resonance control in audio applications, Casser has recently turned his attention to the world of analogue playback, where the control of micro-vibrations and resonances is of the utmost importance. The Round Things record clamp is the latest member of Black Diamond Racing's unimaginatively named, yet justly famous, stable of carbon fiber resonance control products, which includes The Shelf, Those Things and the Mk.III and Mk. IV Pyramid Cones.

Black Diamond Racing's Round Things Record Clamp

The Round Things clamp is a two-piece affair consisting of a thin circular disc, dubbed the "coaster", and a thick rounded puck, both fashioned from carbon fiber and finished in a high gloss. Holes drilled through the center of both components (unthreaded in the case of the coaster, threaded via a brass insert in the case of the puck) accept a turntable spindle ¼" in diameter with a thread density of twenty threads per inch - a configuration chosen for compatibility with VPI's array of turntables. The coaster, in the words of D.J. Casser, "is the interface portion of the clamp", designed to be sandwiched between the LP's label area and the threaded puck. The bottom of the coaster contains a recessed area, said to aid in the coupling of record and clamp, and its edge is beveled to forty-five degrees so as to provide adequate clearance during a cartridge's traversal of the LP's runout groove. Although the Round Things record clamp will work with turntables other than those from VPI (provided, of course, that the spindle is of the appropriate dimensions), I would caution owners of non-VPI turntables to ensure that their turntable's motor is able to cope with its relatively high mass (about fifty-percent greater than that of the stock VPI clamp) before proceeding.

Associated Components

Analog: VPI Aries turntable, Audioquest tonearm, Benz-Micro MC Gold moving coil cartridge, Black Diamond Racing "Round Things" record clamp
Preamplifier: Audible Illusions Modulus 3A with John Curl designed gold MC phono board
Power Amplifiers: Celeste Moon W-5, Sonic Frontiers Power 2
Loudspeakers: ProAc Studio 150, Meadowlark Audio Shearwater
Cables: XLO Type 4 digital cable, D Lin Audio Silver Bullets 4.0 interconnects, Transparent Audio MusicWave Plus loudspeaker cables, Cardas Hex 5C phono interconnect.
Accessories: Echo Busters room treatment products, Lead(less) Balloon turntable stand with Air Head isolation base, Target equipment stands, Black Diamond Racing Mk.III and Mk.IV Pyramid Cones, Nitty Gritty 2.5Fi Mk.II record cleaning machine, Nitty Gritty Pure-2 cleaning fluid, Stylast stylus treatment, 15A dedicated AC outlets.

While the clamp was not accompanied by any form of user documentation (a side-effect of the review sample's early production origins, I suspect), its use is quite obvious. With an LP on the turntable's platter, the coaster is lowered over the spindle until it comes into contact with the LP's label area. The puck is then threaded onto the turntable's spindle and tightened against the top surface of the coaster, the latter being held firmly so that it is not allowed to rotate against, and hence wear, the LP's label. When the clamp is used with one of VPI's turntables, the rubber spindle washer used in conjunction with the stock VPI clamp should be left in place, preventing any "dishing" of the clamped vinyl disc. Although the two-piece, and hence two-handed, nature of the Black Diamond Racing clamp puts it a notch below the one-piece VPI clamp in terms of ease of use, the sonic payback is well worth the additional effort.

I could certainly speculate as to the physical goings on which allow the Round Things record clamp to quite clearly outperform the stock VPI clamp (the ability of the fibrous material used by Black Diamond Racing to more effectively damp motor and bearing induced micro-vibrations, as well as those which result from the stylus/vinyl interface itself, for example), but the clamp's musical, rather than scientific, contributions are what concerns us here, and it is the former which proved nothing short of profound.

Listening
The mid to lower bass region, so vital to music's bloom, body, and bravado, had a degree of weight and tautness with the Round Things clamp which was merely hinted at by the stock VPI clamp. I won't use the oft-abused "the bass plummeted another octave" cliché so favored by the superlative of the month club, as that would certainly be an overstatement. While the VPI Aries' already-superb bottom end extension was subjectively improved by the Round Things, it was the quality, rather than the quantity, of the bass which benefited most. With the VPI clamp at the helm, bass drum and timpani strikes, as well as plucked double bass lines, were rendered in a slightly rounded, inarticulate manner not reminiscent of the live experience. In contrast, the Black Diamond Racing clamp offered a tighter, more articulate presentation, devoid of the moderate, but audible, blur and overhang heard with the VPI clamp.

Owing to its more faithful treatment of both high and low frequency transients, the Round Things imparted a feeling of energy and life to analogue playback not heard with the VPI clamp. The Round Things' portrayal of the finale of Mahler's First Symphony (Zubin Mehta/Israel Philharmonic, London CS 7004) bristled with electricity and excitement, with massed double basses growling intensely, and brass fanfares blaring convincingly. This same recording, heard with the VPI clamp in service, lacked verve and vitality, sounding somewhat bland and dull in comparison. It is often the case that a component or accessory which imparts a feeling of vim and vigor to musical playback does so as a result of etching high-frequency transients. Not so with the Round Things. High-frequency transients heard with the carbon fiber clamp had a degree of smoothness and naturalness unmatched by the VPI clamp, removing the slight edge and glare heard with the latter during the massed brass passages of the aforementioned Mahler First Symphony.

The Round Things' ability to control the inevitable vibrations and resonances associated with vinyl replay allowed the VPI Aries to effortlessly unravel the heretofore unknown wealth of musical detail buried deep within the dense orchestral constructions of Mahler and Anton Bruckner. The multi-layered sonorities of Bruckner's Fourth Symphony (Bernard Haitink/Concertgebouw, Philips 835 385 LY), for example, were more readily heard as individual, yet consonant, musical passages, as opposed to the more homogenized whole heard with the stock VPI clamp.

Conclusion
It is certainly ironic that as phono cartridges have evolved to the point of being able to detect and electrically transform groove modulations of atomic proportions, they have also become more effective at detecting micro-vibrations generated from within the vinyl replay system itself. While much progress has, in fact, been made in physically isolating the electrical transducer from the turntable's drive system, as well as damping resonances in the vinyl disc itself, Black Diamond Racing's Round Things record clamp has made it clear that even a superbly engineered and mechanically-isolated turntable like the VPI Aries is not immune to the ill effects of self-induced vibration and resonance. Indeed, the sonic effect of the carbon fiber clamp on the sound of the Aries was profound (equally so on two different vintages of VPI's TNT to which I was fortunate enough to have access prior to the formal review period). With the Round Things in place of the stock VPI clamp, music had a newfound energy and vitality without the side-effects of edge or glare, mid and lower bass energy was more focused resulting in better low-end articulation, and complex orchestral passages were more readily unraveled - rather impressive for a device which is, after all, comprised of nothing more than two pieces of machined carbon fiber!

While I do not consider myself an inveterate tweaker (I don't dress my cables in jackets or ties, nor do I feel the need to randomly distribute pocket change atop my loudspeakers), I have found the sonic improvement wrought by the Round Things record clamp to far exceed its nominal asking price. I recommend it highly to owners of VPI turntables wishing to get the most from their analogue front ends.


"Round Things" Record Clamp
Manufactured by Black Diamond Racing Inc.
2625 South Greeley Street, Milwaukee, Wisconsin, 53207
Phone: (414) 747-8733, Fax: (414) 747-8734
Price: US$200
Source of review sample: Manufacturer loan
Copyright © 1998 Audiophilia Online Magazine Home