From the LS26 owners maual:
"BAL/SE: Select as appropriate for each input. For source components having balanced (XLR) connections to the LS26, select BAL. For single-ended (RCA) sources, select SE. Once selected for an input source, the setting is memorized."
"BAL/SE: Select as appropriate for each input. For source components having balanced (XLR) connections to the LS26, select BAL. For single-ended (RCA) sources, select SE. Once selected for an input source, the setting is memorized."