Tech 21 SansAmp PSA-1.1
[File:SansAmpPSA1.jpg|thumb|right|SansAmp PSA-1.1]] The SansAmp PSA-1.1 is an improoved version of the classic rack-mount preamplifier unit, the SansAmp PSA-1, designed and distributed by Tech21, a NYC-based bass guitar and guitar effects manufacturer. The PSA-1 came out in the 1990s and is designed to be used either as an overdrive effect, a D.I. box or as a cabinet emulation unit. The pedal also comes in a digital plugin form, developed by Avid, which comes bundled with Pro Tools.
The PSA-1 and 1.1 are all-analog, except of the digital routing capabilities and its presets; including 49 presets for guitar and bass and 77 empty slots for custom preset storage. The pedal features a dual output with both jack and XLR connections, a dual input and an effects loop. It has input and output volume controls, drive control, low and high EQ controls and three control knobs that shape the gain structure, called "Buzz", "Punch" and "Crunch".
Both the PSA-1 and 1.1 units were been used by a variety of famous bassists throughout the years, including Adam Clayton of U2 and Geddy Lee of Rush.
Matt used it for distorted vocals controlled by a custom switch on his pedalboard. It was replaced by the Avalon VT 737SP on the Resistance Tour. Two Tech 21 SansAmp PSA-1.1's were also seen in Chris's bass rack during The Resistance and The 2nd Law eras.