Despite its ultra-compact size -- this 4-channel line mixer is big on features! It yields the highest sonic quality at all output levels boasting ultra low-noise 4580 operational amplifiers for outstanding audio performance -- the same op amps found in its much bigger brethren. Expanding on the capabilities of standard-size mixers is where the MX400 does extremely well for example as a sub-mixer. If you are running short on available channels on your big mixer and need to bring the output of three different keyboards into your mix -- you can simply connect them to the MX400 work out the keyboard mix and connect the MX400s output to a single input on your main mixer. It will catch your eye because its cute as a button but you will want to own one because of what it can do for your performance.