Check the listing for details. 4MS Listen IO Input / Output Amplifier Eurorack Module. Condition: Used. Listed at 109.00 USD. 4MS Listen IOThe 4ms Listen IO is a simple concept packaged into an all-important utility: a module that enables signal level conversion for getting external sound into a Eurorack system and vice versa. Featuring a stereo input with enough gain to get external signals up to Eurorack levels and a stereo output with the ability to scale Euro signals down to line level, the Listen IO is an ideal way to seamlessly connect drum machines, audio interfaces, keyboard synths, Eurorack systems, and more. Dedicated level meters for each input and output channel provide visual indication that makes it clear when signals are coming in and going out at optimal levels, making it easier than ever to tie the whole studio together.Listen IO FeaturesStereo I/O module for Eurorack synthesizersStereo input with up to +30dB gain for boosting external signals to modular levelStereo output for reducing modular levels to suitable line level signals for interfacing with external gear