Valve Amplification Company (VAC) is a U.S. supplier of high end audio electronics, principally utilizing vacuum tube technology.
Beginning with their second product, the CPA1 / CLA1 preamplifier, designs are largely the work of Kevin Hayes, who functions as chief engineer.
VAC continued to operate in Florida until the beginning of the Marantz Classic project, the production phase of which commenced in Durham, NC in January 1996.
It is the only 'auto bias' system in which the volume and character of the music being played does not alter the idle point of the tube.
It is incorporated in VAC power amplifiers as the iQ Intelligent Continuous Automatic Bias System.