Patch Bay and Outboard Gear

Patch Bay

The patch bay is used to control the flow of signal in the control room – to route analog signals to different pieces of hardware and tie lines. 

On a patch bay, outputs are typically on the top row (e.g. output from a mic in the tracking room) and inputs are usually on the bottom row (e.g. inputs into preamps.) The control room patch bay has two rows of outputs (top row of each bay) and two rows of inputs (bottom row of each bay).

Patchbays typically use a configured known as "normalling".  Outputs on the top rows are normalled to the inputs directly below them - this means that, without any patch cable connections, the signal will flow from the output channel above to the input channel below.  (Any exceptions that we've made are labeled not normalled). For example, in the picture above, for columns 17-24 on the top patch strip, the Microphone Pre-amps 3-10 are normalled to (signal automatically flows to) the MOTU 828x Interface Analog Inputs 1-6. Therefore mic pre-amps 3-10 will come straight into MOTU inputs 1-8 (software inputs 3-10). 

Unlabelled inputs/outputs have no connection attached.

The most important labels/connections on the patch bay to know about are the Microphone Preamps 3-10 Outputs, MOTU 828x Analog Inputs/Outputs, Studio Tie Lines (1-4, 5-8, 9-12), and MonCntrl Cue/talk in/out.

As can be seen (by them being directly above/below each other), the Microphone Preamps are normalled to specific MOTU 828x inputs (e.g. 'Grace 1' is directly above input '1/3*', meaning the output from the first (left-hand) Grace preamp is normalled to MOTU analog input 1 / software input 3. The 'Microphone Preamps 3-10 Outputs'  can be used, however, to send signal from the rack-mounted microphone preamps into outboard gear (hardware compressors, EQ's, effects) before going into the MOTU 828x Analog inputs or to send that signal into a different input in the MOTU 828x (other than the one that preamp output is normalled to). There is no 'Mic Preamps inputs' because the XLR sockets in the control room and tracking room (what you plug microphones into) are already routed (patched) straight into certain pre-amp inputs – to send mic signal to a different pre-amp you have to plug the XLR into a different socket.

The MOTU 828x Interface Analog Input connections can be used to re-route any signal into the MOTU. For example, this can be used to send signal from a preamp into outboard gear (e.g. LA-4 compressor) and send the signal from the outboard gear into the MOTU (which then becomes software inputs), or send some other input signal into a specific input. As shown on the patch bay, 'MOTU 828x Interface Analog Inputs ' 1-6 (columns 17-24 on the patch bay) correspond to software inputs 3-10: this is labelled as 1/3*, 2/4*, etc.

The MOTU outputs are used to send outputs from the audio interface (where software outputs go) to different places.    As with the 'MOTU 828x Interface Analog Input', these outputs are numbered as hardware/software input (e.g. a1/3* means analog output 1 (on the hardware) but software output 3 (in the DAW), as are the same). MOTU main L and main R (software outputs 1/2, which is the stereo output/main mix) are normalled straight to the presonus monitor station input ST1 (which then goes through the monitor mix A out into the genelec speakers, left and right). However, these patch points can be used to send any outputs on the MOTU 828x Interface to a different destination. MOTU outputs a5/7 and a6/8 are normalled to the presonus monitor station input ST2.  This is intended for cue mixes (for more information check the Headphones and cue mixes page!).

The Studio Tie Lines connections are used to send audio signal out to the 1/4" plugs labelled 'Studio Tie Lines' in the tracking room. These are used for setting up headphones with cue mixes in the control room. This will be explained in more detail below.

Outboard Gear

 'Outboard gear' refers to rack-mounted, hardware compressors, EQ's, and effects units in the studio. These pieces of equipment can be used  during recording by patching audio from a mic preamp output to the input for a piece of outboard gear and patching the output from the outboard gear to a MOTU 828x input. They can also be used during mixing by patching the desired audio from the software (MOTU 828x output) into the outboard gear, patching the output from the outboard gear into a different MOTU 828x input, and recording the new, processed audio.

Example (for recording with outboard gear) – to send audio from a mic in the tracking room through the first Grace pre-amp, into the LA-4 compressor, and then into software input 3: plug the mic into the appropriate XLR socket (either in the control room or the tracking room) corresponding to the Grace pre-amp 1 (all sockets are labelled with the pre-amp or software input (corresponding to a specific preamp that is normalled to that input) they go to); make sure signal is coming into the pre-amp (make sure the pre-amp is turned on and that phantom power is on if you need it if signal isn't coming through); using the patch bay, patch 'Grace 1' on column 17 of the 'Microphone Preamps 3-10 Outputs' into 'UREI LA4 Inputs' 1 or 2 (column 11/12) (inputs 1/2 just correspond to the left-hand LA4 compressor or the right-hand LA4 compressor, between which there is no difference); then patch 'UREI LA4 Outputs' 1 or 2 (same as whichever input you used) (column15/16, top row) into 'MOTU 828x Interface Analog Inputs' 1/3* (on column 17). Audio from the mic in the tracking room will now flow into the Grace preamp, out of the Grace preamp and into the LA-4 compressor, and out of the LA-4 into software input 3.

LIST OF OUTBOARD GEAR