The Yamaha SPX990 features 20-bit analog-to-digital and digital-to-analog conversion technology, with sampling at 44.1kHz. A true 2-in/2-out stereo configuration that allows stereo sources to be processed without disrupting the original stereo image. Stereo inputs and outputs are all electronically balanced, with XLR and TRS phone jack connectors. In addition to the main effects, the SPX990 provides programmable pre and post effects that can be used to refine and polish your sound.