Spatial resolution and efficiency of the ATLAS muon Monitored Drift Tubes (MDT) depend on drift time resolution, noise levels, and accurate threshold setting. A new 130~nm readout device is developed and optimized for the required time resolution, to guarantee rise times below 10~ns with acceptable time slewing effects. Moreover, the large chain-amplification results in increased sensitivity to any disturbance, mainly from the supply. To avoid additional costs to clean up the setup from such disturbances, the readout chain adopts innovative techniques at system, circuit, and design levels. These are minimizing readout chain disturbance sensitivity. This paper describes the achieved performance by showing measurement results and presenting resolution studies taken in a high energy test beam at CERN.