The introduction of the original Tube Driver 1500 in 1996 began a new era of tube-driven amplification for cars. Shortly after the first production models were shipped, a group of veteran mobile sound professionals from Rockford Fosgate, PPI and others, joined to form a new company named Phaze Audio. At this time, Butler Audio was approached with the idea that it would produce the TubeDriver amplifiers and Phaze Audio would market and sell them. Butler Audio initially granted Phaze Audio an exclusive license for marketing and distribution of the Butler Audio line of TubeDriver amplifiers. In the late fall of 1997, Phaze Audio was also granted a manufacturing license to produce TubeDriver amplifiers.
In 1998, Phaze Audio saw a great opportunity for accelerated market expansion and purchased Precision Power, Inc. (PPI). After the acquisition, Phaze Audio/PPI decided to re-design the original Butler Audio TubeDriver amplifiers. In 1999, PPI came out with a line of amplifiers with tubes bearing the trademark "TubeDriver"; however, they are not BK Butler/Butler Audio designs and do not share in his original patented technology.
Phaze Audio/PPI was purchased in late 1999, temporarly ending all further TubeDriver brand production and sales. Shortly after this, in early 2000, BK Butler reclaimed all of his rights pertaining to TubeDriver. With a clean slate, BK Butler began an all-new design that would ultimately incorporate his newly discovered Tube Driver BLUE thermionic technology. Often working 18-hour days in his personal lab, it's estimated that no fewer than 100 different prototype versions of this new technology were rigorously investigated and thoroughly tested.