The Stanford Reasearch SIM911 is a low-noise, programmable preamplifier which is ideal for a wide range of small signal applications. The SIM911 has a bipolar junction transistor front-end, offers lower input noise, and has a 100 kTone front-end impedance. This module maintains very low output noise resulting in exceptional overall noise performanceToneeven at low gain levels. The bandwidth of this preamplifier is independent of gain setting so waveforms do not change shape as the gain is varied. Dual parallel outputs (one frontand one rear) provide flexibility in cabling. Inputs can be configured as differential (A-B), single-ended (A), or internally grounded, and can be either AC or DC coupled. Additionally, the BNC input shields can be floated, avoiding spurious ground loops when measuring remote signals.