Pilot Comparator

Last updated: 2026-06-01

The Pilot Comparator lets you pick any two presets and hear them side by side on your VL3X. It sends Program Change so the device itself plays each preset, not a software simulation, and it shows a read-only parameter diff between the two. Your loaded preset is always safe: stopping the audition restores whatever was loaded before you started, and nothing is overwritten unless you explicitly save.

Picking the Two Presets

Each side, A and B, picks its source independently. Side A is the first preset and side B is the second; either side can use either source type.

• Device slot: reads the preset over USB with one fresh read per pick (no cache). Type a slot number and press Tab to commit, or scroll the dropdown and click. A slot that has no saved preset is treated as uninitialized, and Pilot offers to initialize it or pick a different one rather than failing silently.
• .syx file: parses a single-preset .syx file from disk. See the scratch-slot note below for how a file gets auditioned on the hardware.

Scratch Slot (auditioning a .syx file)

The VL3X can only play presets that live in its own slots, so to audition a .syx file the Comparator must first write it to a slot. When you start auditioning a .syx side, Pilot asks you to choose a scratch slot: a slot you do not mind overwriting. It refuses the currently-loaded slot, the slot the other side is comparing, and a slot already in use by the other side's scratch write, so you can never clobber a preset you are actively relying on. Once written, the side shows "Scratch Slot A" or "Scratch Slot B" instead of a raw slot number, and it behaves like a normal device slot for the rest of the session.

Hearing A and B

With both sides ready, the transport gives you Hear A, Hear B, and an A/B toggle.

• Hear A / Hear B: Pilot captures whatever slot is currently loaded on your VL3X, then sends Program Change for the side you picked. The A/B toggle snaps to the live side.
• A/B toggle and arrow keys: click either half of the toggle, or press the ← and → arrow keys, to switch between A and B live on the device. The switch happens by Program Change, so you hear the real hardware sound of each preset.
• Stop: ends the audition and sends Program Change to restore the slot that was loaded before you started. If the VL3X was disconnected mid-audition, the restore is best-effort and queues until it reconnects; a Reconnect to restore button appears while disconnected.

The Parameter Diff

Once both sides are ready, a read-only diff panel lists every parameter that differs between A and B, grouped by effect block. Each block card shows a colored dot, the block name, and the number of changes; blocks are expanded by default, and a block with more than three changes can be collapsed to its first three. Each row shows the parameter label, its raw offset, the A value, and the B value.

Two empty-state messages can appear when there are no parameter differences:

• "Identical at step 1" when the two presets match at step 1 and have no metadata differences either. If both sides point to the same device slot, an "A and B point to the same source" hint is added.
• "There are no vocal/guitar differences to show." when step 1 is identical but metadata differs, for example a 1-step preset versus a multi-step preset whose first step matches. A "(Only step 1 is compared right now.)" note explains why the parameter list is empty.

Saving the Live Side

While auditioning, "Save Slot NNN to a new slot" clones whichever side is currently live (A or B) into a destination slot of your choice. The copy is lossless and uses the standard preset-copy path, so the live preset is written byte-for-byte and the originals are not modified. Pilot refuses to save over the currently-loaded slot, the slot Stop will restore, or the slot that is live right now, and it offers to initialize a blank destination slot before saving.