How To Cable GT Rack Effects Modules

This page is under construction.  Some of the articles in the GT Effects section of the site include details and pictures about cabling.

Most modules have three types of cables - audio, switching, and power.  A few modules don't have all three types.  A few modules also have footswitch cables.

Footswitch Cables

Footswitch cables plug into the front of their associated modules.  Usually this will be a Rack Switch module.  Rack Switch modules have one of two types of connectors that match the type of your footswitch.  Just plug them in.  A few other modules, such as the Tube Reverb and Super Nova have extra footswitches, these also plug into the footswitch jacks on the front of those modules.

Most of the footswitches have attached cables.  If they are not long enough, you can get the appropriate connectors and extra cables to extend them.  Very long cables may lower the switching signal enough that the footswitches won't function.  There is a practical limit on this, but we haven't found it yet.  It will depend in part on the quality of cables you use.  We've extended switching cables to 100 feet with no problems.

Always use high quality, shielded cables.  See the 12-Button Footswitch documentation for notes about VGA cables.

When using VGA cables, use the jack screws to screw the connectors to the footswitch and the Rack Switch connectors.  That prevents them from being kicked loose and also helps support the weight of the cables so the pins do not bend.

When you connect the 12 Button Footswitch to a Rack Switch module and power on the Rack Switch module, the power indicator LED on the footswitch should come on.  If it doesn't, the footswitch probably isn't getting power.  Check to see if the power LED on the back of the Rack Switch is on.  Make sure the cable is connected securely.  If the footswitch LED still doesn't come on, try switching a footswitch or two to see if their LEDs come on.  If they come on, the footswitch power indicator LED may be burned out.  Also verify that all 15 pins in your VGA cable are wired.  Some VGA cables use only 13 pins and will not work with the 12 Button Footswitch.

Power Cables

Most modules have DC power connectors on their rear panels.  These are meant for 18V DC, regulated power.  You can use our 18V Power module or your own power supply.  Cable from your power supply to the modules' DC connectors just like you would for regular guitar pedals, using power daisy chain cables.  Each module requires a certain number of milliamps, which you can find in the description for the module.  Make sure your power supply can supply the total number of milliamps for each daisy chain.

If you are using the 18V Power module, it has two power supply connectors.  Each connector can supply about 2000 milliamps of power, enough to power many modules.  The display will show how many milliamps are being used on each channel.  Adjust your daisy chain connections so that you are using about the same amount of power on both channels.  You should use both channels and balance them as best you can.  Using only one channel or having them badly out of balance will decrease the lifespan of the transformer.  They don't have to be balanced exactly, just as best you can with the modules you have.  You can daisy chain daisy chains.  Depending on which modules you are powering, you should be able to power dozens of modules with a single 18V Power module.

Any pedal daisy chain or power cables with the standard 2.1mm DC connectors should be fine.  If you are purchasing new cables, go for shielded ones with larger gauge wires (lower gauge number, eg 24 gauge is bigger than 26 gauge).

Audio Cables

Most modules have a single audio In and single audio Out 1/4" connector, just like normal guitar pedals.  A few have additional connectors for loops and other routing options.  Connect your modules the same way you would connect standard guitar pedals to build your signal chain.

Use short cables where you can.  Use high quality shielded audio cables.  You may need multiple lengths of audio cables, depending on how far apart your modules are installed, whether they are in different enclosures, etc.  Mono or stereo cables will work fine.

Switching Cables

Most modules have one or more connections for a switching cable.  The switching cables connect the module to a Rack Switch, Switch +, or Switch X module which allows you to control the module with a footswitch unit.  The cables are standard audio cables with 1/8" audio connectors like those used for headphones plugged into your phone or mp3 player.  They are male on both ends, either mono or stereo.  Shielded and larger gauge (smaller gauge number) is better.  They are widely available at low cost in a variety of lengths.  The length isn't critical, as long as they are long enough to connect the module.  You may want to get various lengths from 6" to 24" or longer just to avoid having a lot of extra wire to deal with.

You don't have to use the switching cable for a module if you want to leave the switch in one position all the time.  There is an override switch associated with each switch connection.  The override can be set to enable to switching or disable it and leave it on one setting.  That is useful for "always on" and some routing modules where you don't need footswitch control.  Then you don't use up a switch on your footswitch unit.

Usually you'll want footswitch control of your module.  So cable from the footswitch jack on the rear of the module to the Rack Switch, Switch +, or Switch X jack that you want to use to control the module.  Design of switching schemes is discussed separately.

You should always cable the modules' switch jack(s) to a footswitch via one of the switching modules, or use the override switch.  If you do not cable to a switching module and you do not use the override switch, the module may switch erratically or be "stuck" on one switch position.  Do not depend on that undefined behavior - it could change.

General Notes

All the major types of cables (power, switching, and audio) use different types of connectors.  You shouldn't be able to connect power to audio, audio to switching, etc.  You never need any connectors to change one type of connector to another, so don't use them and risk problems.  Obviously, you could damage your equipment if you connect different types of connections.

Once you have everything connected and working properly, you can leave it cabled inside your rack cases.  You may want to tidy up extra wiring so that it is not hanging in a big tangle.  There are rack cabling accessories available from third parties that provide brackets to which you can coil and attach your extra cabling nicely.

If you want to change up your signal chain, do it by adjusting the cabling.  You do not need to move your modules around in your enclosure(s) - just re-cable them differently.

You can cable them however you want, but it may be easiest to do power cabling first, balancing between the two channels if you are using the 18V Power module.  If you are using other power supplies, secure them in your rack and connect all the power cables.  Tidy up your power cabling.  Then connect all the switching cables.  Decide what order you want the modules to be on your footswitch.  This is separate from their order in your signal chain.  You may want certain modules on the easiest to reach footswitches, or some modules using adjacent switches if you want to stomp them together, etc.  You can test the switching using the LED status indicators on the modules and footswitch before you connect all the audio cables.  Finally connect all the audio cabling and test it all.

After you connect all your power cabling, you can power everything up.  The power indicator LEDs on the back of all the modules should come on, indicating the module has power.  If an LED is not on, the module doesn't have power (or possibly the LED is burned out).  If the power LED doesn't come on, connect the switching for the module temporarily and switch it on and off.  If the LED on the front turns on/off as expected, then the power LED may be burned out.  If the front LED doesn't switch on/off, and the power LED is not on, then you probably don't have power to the module.  It could be that both the power and front LEDs are both burned out.  This would be extremely unlikely, but is possible.  To determine if that is the case, cable the module's audio connections and see if it is working.  If it is switching and working OK, then both LEDs may be burned out.  In any case, it is more likely that one of the LEDs isn't actually plugged in correctly to the boards in the module, particularly if you just installed the module or had the enclosure apart for some other reason.  Check to make sure they are plugged in.

If you are using some power source other than the 18V Power module and a module isn't working or sounding right, make sure your power is good.  It should be 18V DC, regulated.  Polarity doesn't matter (center positive or center negative).  Make sure the power supply is capable of providing sufficient power for the connected modules, plus about 20% or so.  If multiple modules are chained to the power supply, disconnect all but one and test each one individually.  Then add modules one at a time to see if you have enough power for them.

Use high quality, low noise power supplies.  Do not use switching power supplies - they are noisy and will make effects sound bad no matter what you do.  The best power supplies and transformers are heavy, not small, light, and inexpensive.

Always power your effect power supplies (and amps and other gear) through a high quality power conditioner to remove power noise, protect your gear from surges and spikes, etc.  This can make a huge difference in the quality of your sound, as well as protect your equipment from a variety of problems.

If you are using third party pedals or rack effects, cable them in just like you would on a pedal board.

The connectors on the internal module cables and boards are not designed to be unplugged and plugged back in a huge number of times.  If they are used that way, they can get loose or start losing connection intermittently.  If that happens, you can replace the cable.  Another option, particularly if you gig and play out is to semi-permanently attach the connectors.  One way to do that is to use a small dab of clear silicone caulk to hold the connector together.  Don't go overboard and goop up the area so much that you won't be able to peel off the silicone when you do need to unplug the connector.  You may also be able to tape them in place.  Do not use superglue or anything else that is permanent.