KHE ACS MIDI Guide
All KHE amp/cab switchers are fully controllable via MIDI. This allows for remote switching of the amps and cabs by a MIDI footswitch or other MIDI controllers. This guide explains the KHEs MIDI operation and how to use it. The use of the KHE’s MIDI function is pretty straightforward. The programming of the MIDI controller or footswitch is often the more challenging aspect. Some controllers are simple, others can be complex. Always refer to your MIDI controller's user manual and study it thoroughly. By the way, the KHE’s MIDI operation is completely safe for the amps—sending incorrect or harmful MIDI data to the KHE is impossible. The KHE filters all incoming MIDI messages, executing only valid switching instructions to make sure the amps are safe and loaded all the time.
“Which MIDI Footswitch to use?” One of the most-asked questions we hear. There are plenty of options! To help you choose the right footswitch, we've listed some examples here: MIDI Footswitches & Controllers
MIDI Operation
First, it’s important to understand how the KHE’s MIDI works. It can be controlled by two types of MIDI commands:
Control Change - CC commands allow to remotely control the KHE’s font panel switches. One footswitch can control one amp or cab (toggle mode only). The footswitch layout can be arranged as follows: Button A: Amp 1, Button B: Amp 2, Button C: Cab 1, Button D: Cab 2 and so on. The MIDI CC command has two parameters: CC number ( = amp or cab number, see manual) and CC value ( = 127).
Program Change - PC commands allow to switch the KHE’s 100 presets. Each preset can be customized with any amp/cab combination. It enables to switch from one amp/cab rig to the next by a single footswitch. The footswitch layout can be arranged as follows: Button A: Preset 1, Button B: Preset 2, Button C: Preset 3 and so on. PC commands can also be used to switch the KHE in sync with patches on multi-fx units. A PC command has one parameter, the PC number (= KHE preset number).
So in short, if you want to load an specific amp and cab at the same time, use PC commands. If you want individual control like the KHE’s frontpanel switches, use CC commands. Keep in mind that a MIDI controller can not show the status of the activated amp or cab on the KHE. MIDI is a one-directional communication, the KHE does not send any data back to the MIDI controller.
More details on the PC and CC programming are provided later in this guide.
It’s important to know that not all MIDI controllers function the same. Many controllers offer both CC and PC functionality. But many controllers are PC only. Some have limited or incompatible CC operation. Make sure to choose a controller that has the right MIDI functionality for your needs and study it’s user manual in detail to ensure compatibility. Learn more: MIDI Footswitches & Controllers
Wiring & Connection
Connect the footswitch MIDI OUT to the KHE's MIDI IN jack using a standard 5-pin MIDI cable. Note that the KHE does not provide MIDI phantom power. Note that the KHE has a MIDI Input port only. It does not have a MIDI OUT or THRU port. Don’t use the CTRL jacks for the MIDI connection - those are not MIDI ports. When daisy-chaining multiple MIDI devices, connect the KHE last in the chain. If this is not possible, add an external MIDI THRU or MIDI MERGER box to split the MIDI signal beforehand. See Little Helpers (coming soon)
Notes:
The KHE CTRL jacks are not MIDI. Don’t connect any MIDI gear to them. The CTRL jacks are specifically designed for linking KHE units.
With some MIDI devices, the power-on startup sequence is critical. Try power on the KHE last in case of problems (after the controller).
Some MIDI devices have a combined MIDI OUT/THRU port, typically set to OUT by default. This may prevents the device from passing through incoming data. Try setting it to THRU. Refer to the controller's user manual for additional information.
When linking multiple KHE switchers, the system can be controlled by a single MIDI footswitch. Learn more: Linked KHE MIDI Control (coming soon)
MIDI Channel Setting
To receive MIDI data, the KHE’s MIDI channel must match the channel number of the sending MIDI controller. The MIDI channel is programmed in the KHE’s System Menu:
Enter the System Menu by pressing the KHE CTRL button for 3 seconds, then release it. The CTRL light starts to blink 1x, indicating “Page 1 - System Functions” is active. “Page 2 - MIDI Menu” has 2x blinks of the CTRL light.
Short-press the CTRL button to switch menu page 2. The CTRL light blinks 2x, showing “Page 2 - MIDI Menu” is active. With the AFX 8, this step is not needed, as it has only one menu page, which is the midi channel setting.
Repeatably short-press switch AMP 1 until the lights match the readout table. The MIDI channel is displayed with the first 4 amp lights in binary. Each press of the switch AMP 1 increases the MIDI channel by +1. The MIDI channel ranges from 1 to 15. With the AFX, which has no amp switches, use the FX/CTRL button instead to increase the MIDI channel.
Exit and save the System Menu by pressing the CTRL button again for 3 seconds, then releasing it. The CTRL turns red (or green if linked) and the switcher is back in normal switching operation. All settings are saved and will be automatically loaded on the next power-up.
Notes:
If multiple KHE switchers are linked, the the first KHE channel setting must be #1.
If multiple MIDI devices and CC commands are used, set each device in the MIDI chain to it's own channel number to avoid data collision. With PC commands, usually all device can have the same channel number.
The very first 30 KHE units from 2019 have a little different MIDI channel setting. See the 2019 ACS User Manual.pdf with all information about it.
Program Change Commands
PC commands allow to switch the KHE’s 100 presets. Each preset can be customized with any amp/cab combination and also the Master-FX-Loop on/off state (4x4FX/AFX). It enables to switch from one amp/cab rig to the next by a single footswitch. PC commands are also usually used to switch the KHE in sync with patches on multi-fx units. Loading presets via MIDI PC works together with the KHE’s Load Detection: it scans all cabinet jacks for a connected load. If a preset is saved with an unused cab output, the KHE will not load the preset for amp safety.
MIDI Controller Configuration & Setup:
A PC command has one parameter, the PC number (= KHE preset number). The PC number represents the KHE preset number (PC#1 = KHE Preset #1). Program the MIDI controller to send an individual PC command for each button. Refer to the user manual of the MIDI controller for more information on the programming. The footswitch layout can be arranged as follows: Button A: Preset 1, Button B: Preset 2, Button C: Preset 3, and so forth.
Creating, Modifying, and Saving KHE Presets:
All 100 KHE presets initially empty, with no amps or cabs programmed. To create a preset:
Load the preset by pressing the MIDI footswitch button with the PC command. The preset is usually empty (nothing will happen visually),
Activate the amp+cab on the KHE. The CTRL light starts to blink red. This indicates that the preset has changed but is not saved yet.
Short-press the CTRL button to save the preset. The CTRL light stops blinking, and the preset is saved.
Presets can be deleted as well: Either overwrite them with no amp or cab activated, or perform a system reset to set all data back to factory settings.
Setup Tip: While configuring MIDI PC settings, have a cabinet activated on the KHE. If the KHE receives a valid PC command, it will load an empty preset, deactivating the cab. This gives some visible and audible feedback to confirm that the KHE is receiving the MIDI data.
For MIDI PC control with linked KHE switchers, see this guide: MIDI with Linked KHE Switchers (coming soon)
Control Change Commands
CC commands allow to remotely control the KHE’s font panel switches: One footswitch controls one amp or cab. It works identical to the front panel switch operation and has the same safety features. The footswitch layout can be arranged as follows: Button A: Amp 1, Button B: Amp 2, Button C: Cab 1, Button D: Cab 2 and so on. Using CC commands usually requires more programming efforts on the controller.
A MIDI CC command has two parameters: CC Number and CC Value. Both data bytes must be sent to the KHE. If one is missing or wrong data is sent, the KHE will not execute the command.
CC Number: The CC number represents the individual amp or ab on the KHE. See the table below.
CC Value: The CC value sends the switching command. It is always set to 127 and operates in toggle mode (ON and OFF value = 127)
MIDI Controller Configuration & Setup:
Program the MIDI controller to send a separate CC command for each button. Set the first CC data value to address the amp or cab (refer to the table). Set the second CC data value to 127. If possible, set the command to toggle operation. Repeat this process for all buttons on the footswitch. Refer to the user manual of the controller for more information.
Notes:
For controllers with an on/off CC value, set both on and off values to 127.
CC works exclusively in Toggle Mode. There are no individual on / off commands.
CC Number #126 disables the active amp and cab (mute / all off).
CC Number #127 toggles the Master-FX-Loop on/off (ACS4x4FX or AFX8).
The lights on the MIDI controller can not represent the actual on/off state of the KHE.
Some MIDI controllers do not support CC operation or have incompatible operation.
The very first 30 KHE units from 2019 have a little different MIDI CC implementation. See the 2019 ACS User Manual.pdf with all information about it.
For MIDI CC control with linked KHE switchers, see this guide: MIDI with Linked KHE Switchers
Troubleshooting & FAQ
The KHE does not respond or react to the MIDI commands at all.
Verify MIDI Input: Ensure the KHE MIDI IN jack is used. Don’t use the CTRL IN or CTRL OUT jack.
Verify MIDI Output: Ensure to use the MIDI OUT port on the controller.
Check MIDI Channel Settings: Confirm the KHE and the controller are set to the same MIDI channel.
Power-On Sequence: Try to turn-on the KHE last, after the controller or other MIDI devices.
Test a Different MIDI Cable: Sometimes even new MIDI cables can cause troubles (they are usually cheap).
Simplify the Setup: If daisy-chained, reduce the MIDI rig to only include the KHE and the controller for the initial setup.
The KHE doesn’t respond with daisy-chained MIDI devices.
Some MIDI devices have a combined MIDI OUT/THRU port, typically set to OUT by default. This may prevents the device from passing through incoming data. Try setting it to THRU. Refer to the controller's user manual for additional information.
The KHE doesn’t work right with CC commands.
Check the programmed CC parameters in the controller (amp/cab number + 127). If on/off parameters are available, set both to 127. Ensure it is set to Toggle Mode. Confirm that your controller supports Toggle Mode or repeated sending of commands
My MIDI Controller cannot send CC#126 or CC#127.
Some MIDI controllers have an limited and incomplete CC data range (120 instead of 127). Refer to the controller user manual for information on the data range. A workaround is to use a 'MIDI event processor' in front of the KHE to modify the data. For instance, remap incoming CC#120 to CC#127. See Little Helpers (coming soon)
I added a new KHE switcher to my old ones, and now if I am loading MIDI PC presets, the KHE reboots.
This can be caused by a preset data collision (safety precaution to avoid loading any invalid combination. Execute a System Reset with all KHE switchers and start with a clean setup again.
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