It was during this time that Flim & the BB's bassist Jimmy Johnson joined the band and, like Husband and Wackerman, remained a regular member of Holdsworth's touring bands until his death. Making his last appearance on vocals was Paul Williams, with whom Holdsworth claimed to have fallen out due to the selling of live bootlegs by Williams. The "Atavachron" album in 1986 was a landmark release in that it was the first to feature Holdsworth's work with a brand new instrument named the SynthAxe. This unusually designed MIDI controller (different from a guitar synthesizer) would become a staple of Holdsworth's playing for the rest of his recording career, during which he would effectively become the public face of the instrument. The next year saw the release of a fourth album, "Sand", which featured no vocals and showcased further SynthAxe experimentation. A second collaboration with Gordon Beck, "With a Heart in My Song", followed in 1988. In the late 1980s, Holdsworth set up his own recording studio named The Brewery in North County, San Diego, which would become one of the main recording locations for all of his studio albums beginning with "Secrets" in 1989, and throughout the 1990s. In a 2005 interview, he stated that he no longer owned the studio following his divorce in 1999. "Secrets" introduced pianist Steve Hunt, who went on to play keyboard as a member of Holdsworth's touring band, and for two further albums. A collaboration in 1990 with fusion guitarist Frank Gambale came about in the form of "Truth in Shredding", an ambitious collaborative project put together by Mark Varney (brother of Shrapnel Records founder Mike Varney) through his Legato Records label. In December of that year, following the death of Level 42 guitarist Alan Murphy in 1989, Holdsworth was recruited by the band to play as a guest musician during a series of concerts at London's Hammersmith Odeon. With former I.O.U. partner Gary Husband now being the drummer for Level 42, these circumstances all led to Holdsworth contributing guitar work on five tracks for their 1991 album, "Guaranteed". Holdsworth would also play on Chad Wackerman's first two studio albums, "Forty Reasons" (1991) and "The View" (1993). Holdsworth's first solo album of the decade was 1992's "Wardenclyffe Tower", which continued to feature the SynthAxe but also displayed his newfound interest in self-designed baritone guitars built by luthier Bill DeLap.