Coffman Labs G1-A feet


G1-A
MONO AND STEREO HIGH-END AUDIO MAGAZINE

Since the release of the G1-A preamplifer, we have received great comments about the unique feet connected to the chassis. We wanted them to look great, but we designed them for more than aesthetics. We wanted them to do a good job of controlling vibration that might reduce the G1-A’s optimal performance level.

Here in Oregon, each foot is custom milled from over-sized solid aluminum billet. A circular groove machined into the bottom surface and an O-ring of rubber-like material is then pressed into the groove. Not only does the ring help anchor the G1-A to the rack and reduce the possibility of sliding, it also serves as the first line of defense in vibration control. What remains of vibration then propagates upward toward the G1-A chassis where a separate internal vibration isolation plate completes the job. Together, these layers significantly reduce vibration before it can find its way to the sensitive tubes and components inside the G1-A.

Most audio equipment doesn’t have a secondary internal isolation solution, but we had an idea of how to extend the G1-A feet concept for general use. Vibrational resonances are dampened by many types of materials, and many single materials like wood, cork, or carbon fiber help with vibration control. However, the vibration dampening effect can be greatly multiplied if several different materials, stacked together, act as a barrier.

After some additional experimentation, we found that two of our custom rubber ringed aluminum feet sandwiching a layer of felt, and compressed with a nylon binding rod provide better isolation from vibration than other options we have tried – including our own stock G1-A feet. Given four different types of material comprising each footer, vibrations reduce dramatically as they pass through the various layers. Ultimately, the feet do a great job isolating electronics so they can perform at their highest level.

There are two main benefits to the footers. First, we believe the result is a slightly smoother, and more natural sound. Second, unlike some vibration control spikes on the market, the rubber ring on the top and bottom of the Coffman Labs Footer helps avoid scratches on your valuable equipment and anchors the equipment to the shelf it’s sitting on.

The Coffman Labs Footers can supplement the stock feet on the G1-A, or they can be purchased separately for use with virtually any piece of audio equipment. Sets of three feet in a broad triangle formation under a piece of equipment will auto-level that component and distribute the weight across the feet. The feet can be tightened or loosened slightly to adjust height if needed.

Each foot can accommodate about 20 pounds maximum when the footer layers are tightened together on the post. Heavier equipment may require four or more feet. Too much weight on a footer will compress the felt to a high degree and bend or strip the nylon post, rendering the footer much less effective. Three feet together can support overt 60lbs, which is sufficient for most equipment. If you have heavier items, we have a custom options available on request—based on your specific needs. We’re currently working on a prototype of a larger foot. Four feet to supplement a G1-A’s existing feet are $100. Note: In this scenario, you will use the feet currently on the unit, and add the other layers under it (eg, for each leg of the G1-A, you receive one aluminum footer with the rubber insert, the felt, and the post which simply screws in under the existing foot.)




Mono and Stereo ultra high end audio magazine 2006-2014. www.monoandstereo.com.