How to Use a Patchbay | LedgerNote Jul 29, 2019Before we get started, let me say that any newcomers to the concept of a patchbay should also read our article called The Best Patchbay for Studio & Live Audio reason is that, before we review any specific models, we give a summarized run down of everything you need to know about these miracle machines, including how to use one. Patchbays 101 - The Pro Audio Files Most modern patchbays use tiny telephone (TT), or bantam connectors on the front. Although, some patchbays use 1/4” TRS or even XLR connectors. The rear typically uses DB-25 connectors to save space, but some units use 1/4” TRS or XLR. DB-25 (or D-sub) cables are multi-pin connectors that can carry 8 analog audio signals simultaneously.