The model 571 wideband preamplifier is designed as a general purpose gain block for instrumentation such as oscilloscopes, spectrum analyzers, and analog-to-digital converters. It offers switchable 20 or 40 dB amplification of signals up to 100 MHz. The input coupling is switchable between direct, single-ended mode (with choice of 50 or 1000 ohm input impedance) and 50 ohm, ac, floating transformer mode. Designed for low impedance sources, the amplifier provides excellent self-noise characteristics.
Unlike the other 500 and 1600 preamplifiers, the 571 is not intended to function as an accessory to DL Instruments lock-in amplifiers, electronic fliters, or instrumentation amplifiers. Only 450 Series amplifiers and 4100 Series filter rack supplies or the model 511 power supply have sufficient current. Otherwise it is expected that the customer will wire in an external line powered or battery powered dc supply via the model 560AE connector supplied with the preamplifier.