Standing for ‘Input Signal Amplifier’, the ISA range was born out of the original Focusrite Forte console of the late 80’s, and later the Focusrite Studio Console. The core modules from these consoles live on with Focusrite’s current range of ISA products, which have in themselves also become recording classics, and the choice of the world’s finest producers and engineers. All ISA products use the Lundahl LL1538 input transformer and a custom Zobel network, both of which contribute to their sought-after sound.