The Pressurizer is an interesting take on compression + boost from Amptweaker, here’s the manufacturer’s presentation, check out the Pro Guitar Shop video below.

Sustain without compression…a common suggestion Amptweaker™ receives that means “don’t mess with my attack.”  The Amptweaker PressuRizer™ compressor accomplishes this in several unique ways, and includes a built-in output FET limiter/booster, making this a powerful clean tone tweaker.  Using parallel studio-grade compression with wet/dry blend, and some unusual side-chain variations, it varies from smooth compression that limits the initial ‘whack’ to a dry-blended approach that adds compression after a short delay.  The PressuRizer is designed to work for both guitar and bass. – More info here