The Focusrite ISA One is a analog portable preamp. I have been using it for about 8 months though it has been out longer than that. It does come with a user manual in digital format in case you need some help getting started but the manual is not necessary to understand how the ISA One works. The ISA One has cue mix stereo inputs and a single channel pre amp. It has an option to go with A to D for a converter as well. If you are looking for a portable preamp that will give your sound the boost it needs to get it to fit better in your mix then the Focusrite ISA One has hit the nail on the head. It has phantom power and the frequency response is 10Hz-125kHz. There is no EQ on the ISA One and no compression. Since it is fully analog there are no connection options like USB so you can connect it to your computer.
This unit is small but well made and it has a handle on the top of it so you can pick it up easily and take it to another place if needed. The ISA One may not be pretty to look at, but it will get the job done.
The variable impedance selector will allow you to channel in on the warmth of your sound and get it just the way you want it to be, and it will do this without messing up the overall quality of your audio sound source.
I am very happy the ISA One and it has done nothing but help us in many ways. We do not use it a lot but when we do use it; it works wonders for our sound. I highly recommend this portable and affordable fully analog preamp. You will be using it for years to come.