Focusrite ISA 828 MkII Classic ISA Mic PreampThe ISA 828 MkII incorporates eight of Focusrite's classic mic preamps, with Lundahl LL1538 transformers on every input. Each channel has the option of mic or line inputs, while inputs 1 4 also feature instrument inputs on the front panel. Each mic pre has variable input impedance, to provide a range of subtly different sonic options when using microphones, including an 'ISA 110' setting, which replicates the impedance of the original Focusrite mic