Digitech 2120 patch editor. SGS 2112 & 2120 VGS Pages MAIN & FAQ PAGE last update: 2010-03-01. SGS stands for „Studio Guitar System“ VGS stands for „Valve Guitar System“ The SGS 2112 and 2120 VGS have identical circuitry. Hardware is electronically and mechanically the same. The 2120 shipped later and, therefore, had later firmware versions. Digitech 2120 patches The following are patches for us..