ISA Series transformer-based preamplifier: Focusrite's classic ISA preamp design based on the original ISA 110, in a highly cost-effective and flexible package Flexible, independent DI channel: independent gain control, output for routing to an amp, independent XLR output on the rear, and routing to the optional A-D converter Optional stereo 192kHz A-D converter: upgrade with an optional digital card that delivers the best A-D performance in its class, with a dynamic range of 118dB Switchable impedance: four input impedances that help shape your sound, including that of the original ISA 110 Dedicated insert point: allows you to place extra processing between the preamplifier or DI and the optional converter, such as an EQ or compressor Back in 1985, a single channel ISA 110 preamp would have cost you about $7,000 (chassis and unit together), or roughly to equivalent of $13,800 in 2010. When you stop and think about it, the ISA One (a topological spot-on recreation of the ISA 110) is almost indecently affordable today. From its genuine Lundahl L1538 transformer to its bespoke zobel network, the ISA One gives you the very heart of the Focusrite sound though top-quality components. It's one of the sweetest vocal preamps on the market, thanks to a variable impedance selector that lets you get the best tone out of just about any mic, and an independent DI lets you capture simply fantastic guitar and bass tone by blending DI and miked amp signals together. If you love to play with sound and get creative with your technique, an ISA One will be one of the most rewarding preamps you'll ever own.