Mods/repairs in San Frncisco Bay Area

Can anyone recommend a skilled tech. in the San Francisco area for mods (and repairs) on my tubed pre/DAC and tubed and SS amps? I appreciate any leads. Thanks!
Nick Gowan from True Sound does high quality repair work and also does mods. He did a fine job repairing OTL amps I owned. Don't know where you are located. Can say he's worth the trip to Campbell if he's familiar with the components you want worked on.
L&M in Daly City

Soundwell in Berkeley

Gene Gerrior in SF

House of Music in SF