Hi Benjamin.
Our recommendation now is no different than it's always been. Tenderfoot isolation feet have always been our default recommendation for all audio components. For tiny components, Baby Booties are sometimes appropriate. Iso-Cups are particularly well-suited as an alternative for amplifiers (and appropriate for audition with virtually any component).
Tenderfoot isolation feet and Iso-Cups are both state of the art and top-of-the-line products. Neither is inherently better than the other and comparative differences between the two will vary somewhat from one component and system to another. Tenderfoot is more versatile though, being at home with a broader array of components.
Tenderfoot and Iso-Cups both provide superb amplifier isolation. Iso-Cups, however, will often give an advantage and preference. Customers who have tried both with amplifiers sometimes choose to keep the Tenderfeet, though usually Iso-Cups are preferred. Many of our customers use Tenderfoot under some components and Iso-Cups under others. Almost always that I know of, Iso-Cups end up under the amplifier and Tenderfoot under the other components.
With small-signal components, Tenderfoot is rarely surpassed, especially with DACs. However, we have many customers using Iso-Cups with DACs, CD players, power supplies, sometimes all the components in their system, with excellent results. In most cases, you wouldn't go wrong with either type of footer supporting a component. With other factors being equivalent, we will recommend the lower-cost alternative, another reason Tenderfoot is the default recommendation.
This controversy of Iso-Cups versus Tenderfoot has been going on for years, because neither has been able to knock the other off the pedestal. Both have incrementally improved over the years, continuing to provide state-of-the-art audio and video component isolation.
Lighter components that do not weigh much often have a tendency to slide on Iso-Cup balls. This can be somewhat of an inconvenience with CD players and other components where you have drawers opening, knobs to turn, etc.
Because amplifiers have on-board transformers producing hum and other factors, amps are somewhat unique regarding vibration-control requirements. We have always experimented with Iso-Cup/ball combinations and tweaked Iso-Cup formulas to achieve optimal results specifically with tube amplifiers, so it's no accident they tend to provide optimal results with amplifiers. (Loudspeakers are a different animal altogether regarding isolation and vibration control, requiring a completely different approach to isolation other than Tenderfoot or Iso-Cups.)
Anyway, Tenderfoot is our default recommendation for components other than amplifiers. That's not to say that you "should" use Tenderfeet instead of Iso-Cups, though.
Steve
Herbie's Audio Lab
