Focusrite ISA428 MKII Classic ISA 4-Channel Mic PreNow in its second generation, the ISA 428 Mk II incorporates four of Focusrite's renowned mic pres in a simple to operate 2U enclosure, placing four mic preamps, instrument inputs and line ins at your fingertips. The original Focusrite mic pre was designed to suit the microphones of the time; today's model makes one small change, adding three additional input impedances to the classic ISA110 setting, allowing you to match any microphone, old or new,