There are rear panel XLR and TRS mic/line connectors and a separate DI instrument input--you're able to record a mic and DI at the same time. Besides gain up to 80dB gain, polarity flip, there is a mic impedance selector, 48-volt phantom on/off switch, a 75Hz rumble filter and an insert in/out for connecting an outboard processor.

I tested the ISA One here at my Tones 4 $ Studios and found it to be a complete professional system complete with a cue system that monitors either your DAW or the live mic and/or line sources directly for zero latency. I liked the unit's desktop look, large VU meter and most of all, its lush sound.

I recorded both vocals and a Martin D-28 acoustic guitar using a Violet Wedge large diaphragm condenser mic without EQ or compression. It is exactly like I remember using the original ISA 110 module except it is easier to "ride gain on the fly" with the One's 20dB of fine gain control and larger knob.

I used both channels to record a bass and a guitar--direct bass and a Royer R-121 mic on the amp. I monitored through the unit's headphone system and found it to sound super quiet and clean with plenty of power to drive my 55-ohm AKG K271s phones loudly.