PEARL Tube Coolers have been in continuous production for 20 years, during which time over 300,000 pieces have found their way into audio systems the world over. Perhaps the longest running and most successful tube audio accessory of all time PEARL coolers have inspired a host of much more costly imitators, none of which combines the functions of cooling and microphonic reduction achieved by the long-established PEARL design.
Based on research begun in the early 1950s by the US military and the aeronautical industry, PEARL coolers achieve the glass temperature reductions shown over 50 years ago to greatly increase the operating life of soft-glass enclosed electron tubes. Determined during the '50s research is the fact that the "soft glass" almost always used in receiving tube manufacture is susceptible to high temperature operation in that it becomes effectively "porous" at elevated temperatures, thereby allowing atmospheric contamination of the high vacuum within the glass. By several extensively researched and solidly confirmed mechanisms such contamination has been shown to have destructive effects on the electron emitting surfaces upon which tube functioning is completely dependent and extended tube life relies.
Fits the next tubes:: 6L6, 5881 6LF6 KT66 6550 (GE)