iPhone & iPad / USB MIDI

StajPilot for iPhone & iPad

A stage-ready MIDI controller and performance display for the KEMPER PROFILER Player.

Get StajPilot on the App Store Connection guide

Available at an introductory launch price. Check the App Store for your local price.

StajPilot's landscape controller showing eight effect blocks, detailed effect names, Fixed FX, rig information, gain, tempo and five slots — Your rig, effects and essential controls, together on one landscape display.

Wired USB MIDI
No account
No subscription
No internet needed to use the app

On stage

See your rig. Stay in control.

Effects, with their actual names

See detailed effect names and the live on/off status of eight rig FX blocks. Touch a block to control it. Fixed FX have their own controls, with state updates when switching rigs rather than continuous real-time state synchronization. Touch and Always modes are available.

Rigs and performance controls

Five slot controls, bank navigation, rig names, author and amplifier names, gain and tempo information. Tap Tempo and Pedal Morph display keep essential performance information close at hand.

Two ways to tune

Choose a Needle or Strobe tuner display. Open the tuner by double-tapping the rig-name area.

Your own Song Mode

A StajPilot feature for organizing custom song, slot and sub names. Your Song setup is stored on your device and retained through normal app updates. Deleting the app may remove that data.

The Needle tuner display in StajPilot — Needle tuner

StajPilot Song editor with a song name and five slot name and subname entries — Song Mode: names that make sense to you

Streaming first

Most display information uses real-time MIDI streaming, and many supported controls use two-way MIDI communication. StajPilot does not use continuous millisecond-interval polling to imitate real-time streaming. Features that require periodic polling remain disabled by default and are enabled only when needed, avoiding unnecessary load on the Player.

Explore before connecting. Tap DEMO at the bottom-right of the waiting screen to explore the interface without hardware. Demo Mode does not send MIDI commands.

Getting started

A direct connection to your Player.

Use the Player's USB-B port, a short data-capable USB cable, and an adapter appropriate for your iPhone or iPad.

Device tested: StajPilot was confirmed working on an iPhone 7 running iOS 15.3.

Power on the Player
Make sure your KEMPER PROFILER Player is powered on.
Make the USB connection
Connect your iPhone or iPad to the Player's USB-B port. A charge-only cable will not work.
Open StajPilot
The waiting screen changes to the main display once MIDI communication begins. Bluetooth pairing is not required; this iOS version uses wired USB MIDI.

Lightning iPhone or iPad

Use a compatible Lightning USB camera/host adapter and a USB data cable to the Player. If you already use an appropriate Apple camera adapter, an additional OTG adapter is not automatically required.

USB-C iPhone or iPad

Use a compatible USB-C data connection. A suitable USB Host/OTG adapter may improve connection compatibility when a direct connection behaves inconsistently.

Connection help

Start with what iOS can see.

A MIDI monitor such as MIDI Wrench can help distinguish device recognition from actual MIDI reception.

Does “Profiler” appear in the MIDI device list?

If not, iOS has not exposed the Player as a MIDI device. StajPilot cannot communicate with a device that the operating system has not made available. Check the cable, adapter, Player power and physical connection first.

If Profiler does appear, check whether new MIDI messages arrive. A listed device does not, on its own, guarantee that every message is being received.

Stuck on “Waiting for Device”

Confirm the Player is on, the cable supports data, and you are connected to the Player's USB-B port. Check for Profiler in a MIDI monitor. If it is absent, try a different short data cable and compatible adapter.

“USB Connected” appears, but information does not

Connection detection is not confirmation of active MIDI streaming or complete data reception. Check for new messages in a MIDI monitor, then reconnect and try another cable/adapter combination if necessary.

Some rig or effect information is missing

A partial display does not prove that the whole connection is working correctly. Check incoming MIDI, connector fit and cable strain. Try a different cable and adapter, and note which information is missing when contacting support.

The bank and slot show “---”

The current bank/slot number has not been established. StajPilot avoids presenting an unconfirmed number as current. This does not, by itself, mean all MIDI communication has stopped. The app can still display received rig/effect information, and slot controls remain available.

Reconnection or returning to the app fails

Close StajPilot fully, disconnect the USB connection, confirm the Player is on, reconnect, then reopen the app. If the behavior depends on plug orientation or connection order, test a different compatible host adapter. Record the exact sequence if the problem persists.

Still need a hand?

Send your device model, iOS/iPadOS version, Player firmware, cable and adapter details, and the steps that reproduce the issue.

Contact support

Behind the connection

Tested beyond the app's own screen.

~30USB cables compared

iPhone + iPadPhysical-device testing

USB + MIDISystem and message-level checks

As a guitarist, I wanted StajPilot to be something I could trust on stage. That meant looking beyond whether the app connected once.

I tested around 30 USB cables and several adapter combinations, repeatedly checking connections, reconnections, returning to the app and changing rigs. I also compared results with Android devices and the hardware version of StajPilot. The same connection setup did not always behave the same way across devices.

The investigation went beyond StajPilot's own logs. I used MIDI Wrench to inspect device recognition and incoming MIDI messages, and Apple Console to examine system-level USB errors involving the Profiler. I also traced incoming MIDI through the app's native input, message handling and display updates.

This work informed improvements to MIDI input and initial connection/reconnection handling. Rather than assuming that a partial display meant an app error, I checked where the information actually stopped arriving.

MIDI Wrench lists Profiler as a CoreMIDI device and shows incoming MIDI events. Unrelated personal device names are covered. — **Device recognition & incoming MIDI**MIDI Wrench was used to inspect MIDI independently of StajPilot. Profiler appears in the device list; the event area shows received messages.

AppleUSBIORequest log entries for Profiler endpoint 0x83 report status 0xe00002ed, transaction error, with 0 bytes transferred — **System-level USB transfer errors**Apple Console recorded repeated transaction errors involving Profiler. The failed USB requests shown report 0 bytes transferred.

These images document tools used during the investigation, not a synchronized capture. Cable and adapter compatibility can still vary between devices.

Technical detail: the USB log

The captured entries identify Profiler@00100000, endpoint 0x83, and status 0xe00002ed (transaction error). The byte count applies to the failed requests shown. The log records a failed USB transfer; it does not identify the exact electrical cause.

Built by a guitarist, for the stage.

StajPilot began with a personal frustration: navigating hundreds of rigs without a display. I first built the hardware solution for myself and later shared the firmware, supported by donations. The iOS and Android apps grew from the same idea: make essential rig information and controls more accessible to other guitar players.

Available now