How Does Patchbay Normalling Work? With Examples

Summary

A patchbay brings the inputs and outputs of studio equipment to one accessible panel, making signal paths easier to see and change. The video explains three common normalling modes using a setup with a microphone, preamp, two compressors, and a two-channel audio interface. In the examples, equipment outputs are connected to the top row and inputs to the bottom row.

Normalling modes

Non-normalled

• The patchbay routes connections from the back of the rack to the front.
• No devices are connected by default; each connection must be made with a patch cable.
• For the example recording chain, the user patches the microphone to the preamp, the preamp to a compressor, and the compressor to an interface channel.
• Connections are easy to access and rearrange, but must be made manually.

Fully normalled

• Each vertical pair has a default connection: the top-row output feeds the corresponding bottom-row input, even when no patch cable is present.
• Equipment can be arranged so the usual signal chain works without front-panel patch cables.
• Inserting a cable into either the output or input of a pair breaks that pair’s default connection.
• In the example, patching the preamp output to the second compressor’s input overrides the usual route. The compressor can then feed its already-normalled interface channel, or an extra patch cable can route it to a different interface channel.

Half-normalled

• Default connections work much like fully normalled connections, but patching from a top-row output copies the signal instead of interrupting its normal route.
• Patching into a bottom-row input still breaks that input’s default connection.
• This allows the preamp signal to feed a second compressor while continuing through the first compressor. The two compressor outputs can then feed separate interface channels, allowing both versions to be recorded simultaneously.
• A signal can be copied from an output, but separate signals cannot be combined into one input.

How the wiring works

Normalling is implemented with switches attached to the jacks. Inserting a plug opens the relevant switch contacts.

• In a non-normalled bay, the switches are unused, so signals pass between equipment only through inserted patch cables. The video gives an ART XLR patchbay as an example of straightforward back-to-front routing.
• In a fully normalled bay, the switch contacts connect the top output to the bottom input when no plugs are inserted. Inserting a cable at either point opens the switch and breaks the default path.
• In a half-normalled bay, the top-output signal is taken from the wiring before the switch contacts. Patching from that output therefore copies the signal, while patching into the bottom input opens the switch and interrupts the default connection.

The video concludes that patchbays are often useful for working with outboard audio gear, while noting their cost and referring viewers to the creator’s earlier video about modifying an inexpensive unit for a home studio.

Speaker or source featured

• TeDubbs — the video’s narrator and presenter.