Line 6 Helix Floor/LT/Rack Usage Guide

Expert guidance for using the Helix device library in MIDI Markdown files.

When to Use This Skill

Invoke this skill when working with:

Line 6 Helix Floor, LT, or Rack guitar processors
Helix preset and setlist management
8-snapshot control (full range)
Helix expression pedal automation (EXP1, EXP2, EXP3)
11 footswitch control (FS1-5, FS7-11)
Helix Looper functionality
Command Center macros for external gear

Quick Start

Import the Library

mml

@import "devices/helix.mmd"

Basic Preset Loading

mml

[00:00.000]
# Load Setlist 1 (CC32=0), Preset 6 (PC=5)
- helix_load 1 0 5

# Load preset and switch to snapshot
- helix_load_snapshot 1 0 5 2  # Setlist 1, Preset 6, Snapshot 3

Snapshot Control

mml

[00:00.000]
# Named snapshots (1-8)
- helix_snap_1 1
- helix_snap_2 1
- helix_snap_3 1

# Parameterized (0-7)
- helix_snapshot 1 3  # Snapshot 4

Critical Firmware Timing Requirements

Firmware 3.5x: Conservative Timing Required

CRITICAL: Add 350ms delay after ALL Program Change messages before sending CC

mml

# ❌ WRONG - No delay (firmware 3.5x)
[00:00.000]
- pc 1.10
- cc 1.69.2  # Snapshot might be ignored!

# ✅ CORRECT - Use helper with delays
[00:00.000]
- helix_load_snapshot 1 0 10 2  # Built-in 350ms delay

Firmware 3.10+: Improved Timing

Improvement: CC69 (snapshot) messages are buffered during preset load

Still recommended: Use 350ms delay for safety with complex presets

Firmware 3.80 (Current): Stable

Known Issue: MIDI Clock Rx doesn't apply on preset change

Workaround: Use Tap Tempo (CC64) after preset changes if tempo sync is critical

Preset and Setlist Management

Understanding Helix Addressing

Structure: 8 Setlists × 128 Presets = 1024 total presets

Addressing:

CC0 (Bank MSB) + CC32 (Bank LSB) = Setlist selector
CC32 values 0-7 select Setlists 1-8
PC values 0-127 select Presets 1-128 within active setlist

Complete Preset Load

mml

[00:00.000]
# Load Setlist 3, Preset 20
- helix_load 1 2 19  # CC32=2, PC=19 (0-indexed)

# With specific snapshot
- helix_load_snapshot 1 2 19 3  # Snapshot 4

# Direct setlist selection
- helix_setlist 1 2  # Setlist 3

# Direct preset within current setlist
- helix_preset 1 19  # Preset 20

Snapshot Control (8 Snapshots)

Full 8-Snapshot Range

The Helix Floor/LT/Rack has 8 snapshots (0-7), providing maximum flexibility for live performance.

mml

[00:00.000]
# Named snapshots
- helix_snap_1 1  # Snapshot 1
- helix_snap_2 1  # Snapshot 2
- helix_snap_3 1  # Snapshot 3
- helix_snap_4 1  # Snapshot 4
- helix_snap_5 1  # Snapshot 5
- helix_snap_6 1  # Snapshot 6
- helix_snap_7 1  # Snapshot 7
- helix_snap_8 1  # Snapshot 8

# Parameterized
- helix_snapshot 1 7  # Snapshot 8

8-Snapshot Song Arrangement

mml

[00:00.000]
- helix_load 1 0 5  # Load song preset

# Intro - Clean
- helix_snap_1 1

# Verse - Rhythm
[00:16.000]
- helix_snap_2 1

# Pre-Chorus - Add delay
[00:28.000]
- helix_snap_3 1

# Chorus - Drive + reverb
[00:32.000]
- helix_snap_4 1

# Bridge - Ambient
[00:48.000]
- helix_snap_5 1

# Solo - Lead tone
[01:04.000]
- helix_snap_6 1

# Breakdown - Clean + tremolo
[01:20.000]
- helix_snap_7 1

# Final chorus - Epic lead
[01:36.000]
- helix_snap_8 1

Expression Pedal Control

Three Expression Pedals

Helix Floor/Rack models have 3 expression pedals (EXP1, EXP2, EXP3).

mml

[00:00.000]
# Direct MIDI values (0-127)
- line6_exp1 1 64   # From common library
- line6_exp2 1 100
- helix_exp3 1 80   # EXP3 is Helix-specific

# With modulation curves
- line6_exp_swell 1 1 0 127  # Smooth EXP1 swell
- helix_exp3_swell 1 0 127   # Smooth EXP3 swell

Advanced Expression Modulation

mml

[00:00.000]
# Vibrato effect
- line6_exp_vibrato 1 1 64 2.5 20
# Params: ch, exp_num, center, freq(Hz), depth(%)

# Tremolo effect
- line6_exp_tremolo 1 1 64 4.0 30

# ADSR envelope
- line6_exp_envelope 1 1

# Attack-Release envelope
- line6_exp_ar 1 1 0.5 1.0

Footswitch Control

11 Footswitches Available

Full Helix models have 11 footswitches (FS1-5, FS7-11). FS6 is reserved for internal use.

mml

[00:00.000]
# Toggle footswitches (ALWAYS toggle, can't force on/off)
- line6_fs1 1
- line6_fs2 1
- line6_fs3 1
- line6_fs4 1
- line6_fs5 1
# FS6 is RESERVED
- line6_fs7 1
- line6_fs8 1
- line6_fs9 1
- line6_fs10 1
- line6_fs11 1

Important: Helix footswitches ALWAYS toggle. Cannot force on/off via MIDI.

Looper Control

Basic Looper Workflow

mml

[00:00.000]
# Start recording
- line6_looper_start_recording 1

[+8s]
# Switch to playback
- line6_looper_playback 1

[+16s]
# Overdub
- line6_looper_overdub 1

[+24s]
# Stop and exit
- line6_looper_stop_exit 1

Complete Looper Functions

mml

[00:00.000]
# Record/Overdub/Play
- line6_looper_rec_play 1
- line6_looper_overdub 1
- line6_looper_playback 1

# Reverse and half speed
- line6_looper_reverse 1
- line6_looper_halfspeed 1

# Undo/redo
- line6_looper_undo 1

# Stop and clear
- line6_looper_stop_exit 1

Tap Tempo

mml

[00:00.000]
# Send 4 taps at 120 BPM (500ms intervals)
- line6_tap 1
[+500ms]
- line6_tap 1
[+500ms]
- line6_tap 1
[+500ms]
- line6_tap 1

Command Center Macros

Controlling External Gear

Command Center allows Helix to send MIDI to external devices.

mml

[00:00.000]
# Load Helix preset and switch external amp channel
- helix_preset_with_amp_switch 1 0 5 2 10
# Params: ch, setlist, preset, amp_channel, delay_preset

# Load Helix preset, send PC to amp, PC to delay

# Snapshot change with external reverb mix
- helix_snapshot_with_reverb 1 3 64
# Params: ch, snapshot, reverb_mix_value

Complete Song Section Macro

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[00:00.000]
# Complete section: preset + snapshot + tempo
- helix_song_section 1 10 2 120
# Params: ch, section_preset, snapshot, tempo_bpm

Common Workflow Patterns

Song-Based Preset Organization

mml

[00:00.000]
# Song 1: Load preset, use snapshots for sections
- helix_load 1 0 0  # Setlist 1, Preset 1

# Intro
- helix_snap_1 1

# Verse
[00:16.000]
- helix_snap_2 1

# Chorus
[00:32.000]
- helix_snap_3 1

# Solo
[00:48.000]
- helix_snap_4 1

Setlist Organization Strategy

Recommended:

Setlist 1: Covers/Standards
Setlist 2: Originals Set 1
Setlist 3: Originals Set 2
Setlist 4-8: Special projects, recording, etc.

Reserved CC Numbers

Helix-Specific Reserved CCs

CC0   - Bank Select MSB
CC3   - Expression Pedal 3 (Helix Floor/Rack only)
CC32  - Bank Select LSB (Setlist selector)
CC64  - Tap Tempo
CC68  - Amp/Cab toggle
CC69  - Snapshot select
CC70-76 - Reserved for future use

All other CC numbers (4-31, 33-48, 77-127) are available for:

Block bypass control (via MIDI Learn)
Parameter control (via MIDI Learn)
Custom assignments per preset

Firmware-Specific Best Practices

Firmware 3.5x

mml

# ✅ Add 350ms after ALL PC messages
[00:00.000]
- pc 1.10
[+350ms]
- cc 1.69.2  # Now snapshot will work

# ✅ Add 100ms between rapid CC messages
[00:00.000]
- cc 1.51.64
[+100ms]
- cc 1.52.80

# ✅ Use snapshot-based workflow to avoid PC delays

Firmware 3.10+

mml

# ✅ CC69 is buffered - can reduce delays to +50ms
[00:00.000]
- pc 1.10
[+50ms]
- cc 1.69.2

# ✅ Still recommend +350ms for safety with complex presets

Firmware 3.80 (Current)

mml

# ✅ Use Tap Tempo after preset changes if tempo sync critical
[00:00.000]
- pc 1.10
[+350ms]
- line6_tap 1  # Sync tempo

Connection Recommendations

5-Pin DIN MIDI vs USB

Helix Floor/LT/Rack has both:

5-pin DIN MIDI (In/Out/Thru)
USB MIDI

For MIDI Clock (sync):

✅ Prefer 5-pin DIN - lower jitter, more reliable
❌ USB MIDI has higher jitter

For general control:

Either works fine
USB is more convenient for DAW integration

For live performance:

5-pin DIN is more robust
Easier hardware daisy-chaining
Optical isolation (no ground loops)

Common Mistakes and Fixes

Mistake 1: No Delay After PC (Firmware 3.5x)

mml

# ❌ WRONG
[00:00.000]
- pc 1.10
- cc 1.69.2  # Ignored!

# ✅ CORRECT
[00:00.000]
- helix_load_snapshot 1 0 10 2  # Built-in delay

Mistake 2: Trying to Force Footswitch On/Off

mml

# ❌ WRONG - Footswitches always toggle
[00:00.000]
- cc 1.51.0    # Trying to force off
- cc 1.51.127  # Trying to force on

# ✅ CORRECT - Use toggle commands
[00:00.000]
- line6_fs1 1  # Toggles state

Mistake 3: Using USB MIDI for Clock

mml

# ⚠️ SUBOPTIMAL - USB has jitter
# Use 5-pin DIN for MIDI Clock instead

Comparison: Helix vs HX Models

Helix Floor/LT/Rack (You Are Here)

✅ 8 snapshots (maximum flexibility)
✅ 11 footswitches (Floor/LT)
✅ 3 expression pedals (Floor/Rack)
✅ 5-pin DIN MIDI (hardware chaining)
✅ Dual DSP path
✅ Full Command Center
❌ Larger footprint

HX Stomp XL

⚠️ 4 snapshots (good for most songs)
⚠️ 8 footswitches (adequate)
⚠️ 2 expression pedals
❌ USB MIDI only (no 5-pin DIN)
❌ Single DSP path
✅ Command Center (enhanced vs HX Stomp)
✅ Smaller footprint

HX Stomp

❌ 3 snapshots (limited)
❌ 5 footswitches (limited)
⚠️ 2 expression pedals
❌ USB MIDI only
❌ Single DSP path
⚠️ Limited Command Center
✅ Smallest footprint

Troubleshooting

Issue	Solution
Snapshots don't switch	Add 350ms delay after PC (firmware 3.5x) or use 3.10+
Footswitches don't work	Helix footswitches toggle only, can't force on/off
Expression is glitchy	Send smooth CC curves, check MIDI rate limiting
MIDI timing is sloppy	Use 5-pin DIN instead of USB for clock
Preset changes ignored	Check MIDI Base Channel in Global Settings
Tempo doesn't sync on PC	Use Tap Tempo (CC64) after preset change (firmware 3.80)

Reference

Device Library Location

Main: devices/helix.mmd
Common: devices/line6_common.mmd (imported automatically)

Documentation

Official Manual: https://line6.com/support/manuals/helix
Firmware Notes: https://line6.com/software/reaper-extension

Firmware Version

3.80 (current as of library version)