The CardMaster 21.255G is a versatile single-channel signal conditioning filter/amplifier designed for flexible operation and ease of use. With front panel control of filter frequency and gain, it avoids fixed factory settings or internal switch adjustments, allowing quick configuration during testing. Each channel supports single-ended or differential inputs, AC/DC coupling, and an integrated 24VDC, 4mA IEPE (ICP®) supply for direct use with compatible transducers. Signal level is clearly indicated by a three-color display, with additional overload indicators for protection. Up to 18 channels can be installed in a 19” rack (17 channels with optional Ethernet interface), or as a rugged standalone unit. The system offers nine gain steps up to ×500, filter bypass mode, and removable knobs to prevent accidental changes, making it ideal for applications requiring both stability and adaptability in signal conditioning.