FM-1 + D MINI with MidiPipe

One USB keyboard, seven synth parts plus drums and an external Behringer D MINI. The Mac routes MIDI; D MINI plays track 1, while tracks 2–7 and drums use the FM-1’s internal sounds.

Piterfly 1.1.0. This setup uses a Mac as the USB host and MIDI router. The release has been tested on the physical FM-1 and accepted by the project owner.

1. Connect all three devices to the Mac

Use three separate USB data cables, directly into the Mac or through a USB hub that supports data. The Mac is the USB host.

Keyboard

External USB MIDI keyboard

FM-1

MIDI port: piterfly

D MINI

USB MIDI connection

Mac

MidiPipe

Three devices
One USB host

Piterfly 1.1.0 appears as piterfly in the MIDI input and output lists. Select that port for the FM-1 in MidiPipe.

2. Connect the audio outputs separately

FM-1 audio

Internal synth parts 2–7 and drums

D MINI audio

External sound for track 1

Mixer / interface

Speakers or headphones

MIDI tells D MINI which notes to play. Hear its sound from its own audio output, alongside the FM-1’s audio.

3. Put these four tools in one MyPipe

MyPipe is the name of your routing chain in MidiPipe. See the official MidiPipe documentation and downloads (SubtleSoft) for the program’s tools and help.

Keep both connections in the same MyPipe. In the right-hand Pipes column, arrange the tools from top to bottom as shown.

MyPipe

Select each tool and choose its MIDI Input or MIDI Output port.

MIDI InYour USB keyboardMIDI Input: the keyboard’s actual port name
MIDI OutpiterflyMIDI Output: FM-1
Pass Through: OFF
MIDI InpiterflyMIDI Input: FM-1
MIDI OutD MINIMIDI Output: the external synth

Select the first MIDI In. Set MIDI Input to your external keyboard.
Select the first MIDI Out. Set MIDI Output to piterfly and turn Pass Through OFF. Keyboard messages are delivered to FM-1 and stop continuing through that part of MyPipe.
Select the second MIDI In. Set MIDI Input to piterfly; this receives messages that FM-1 actually sends.
Select the second MIDI Out. Set MIDI Output to D MINI.
Remove redundant Channel Router and Channel Filter tools from this main setup. The channels stay 1–7→1–7, 10→10.
Use File → Save and keep MidiPipe running while using the setup.

Two different “through” settings: MidiPipe’s Pass Through OFF stops a message continuing to later tools after the first MIDI Out. The piterfly GLO → MIDI THRU switch controls whether FM-1 sends received notes back out. These settings do different jobs.

4. Keep the MIDI channels unchanged

FM-1 track	MIDI in → out	Sound
Track 1	`1 → 1`	Behringer D MINI
Track 2	`2 → 2`	FM-1 internal synth
Track 3	`3 → 3`	FM-1 internal synth
Track 4	`4 → 4`	FM-1 internal synth
Track 5	`5 → 5`	FM-1 internal synth
Track 6	`6 → 6`	FM-1 internal synth
Track 7	`7 → 7`	FM-1 internal synth
Track 8	`10 → 10`	FM-1 drums

Choose the instrument by changing the keyboard’s transmit channel. Selecting a different track on the FM-1 screen does not change the external keyboard’s channel. This recipe uses IN = NOTES, with fixed track assignments.

FM-1 MIDI page: CH1 1, CH2 2, CH3 3, DRUM 10 — **CH1 = 1, CH2 = 2, CH3 = 3, DRUM = 10.** Keep CH1 assigned to 1; setting it to OFF also disables that track’s MIDI output.

FM-1 MIDI 2 page: IN NOTES, OTHER OFF, OUT SEQ — **IN = NOTES, OTHER = OFF, OUT = SEQ.** OTHER OFF ignores unassigned input channels. SEL also leaves 1–7/10 unchanged, but lets other channels play the selected track.

FM-1 HOME with track 1 selected and LEVEL 0 — Select track 1 with **PRESETS** in current piterfly (**ALGORITHM** in stock SLOOP), then set **KNOB 2 · LEVEL = 0**. Keep this level in every pattern used for the setup.

On D MINI: set its MIDI receive channel to 1 only, connect its audio output to your listening setup, and use channels 2–7 and 10 for the remaining parts. MidiPipe can then send all FM-1 output channels to it without a channel filter in the main pipe.

These are renders of piterfly’s actual UI. The common MIDI settings also describe the original SLOOP setup; the MIDI THRU page shown below is a piterfly addition.

5. Live keyboard with piterfly MIDI THRU

The current piterfly firmware adds per-track forwarding for the channel assignments above. With that build installed, turn TRK1 ON on GLO → MIDI THRU to send received track 1 notes back to USB MIDI OUT. The second MidiPipe input then receives them and sends them to D MINI.

piterfly MIDI THRU: TRK1 ON, TRK2 OFF, TRK3 OFF, DRUM OFF — Per-track forwarding for live keyboard notes.

Keyboard ch 1 → FM-1 track 1 → MidiPipe → D MINI ch 1.

Keep CH1 = 1 and IN = NOTES. The current per-track THRU works with this fixed map; the added synth parts use their own channel assignments on MIDI 4-7.

THRU forwards Note On/Off and velocity. CC, sustain and pitch bend are not forwarded. MIDI 4-7 assigns channels for added synth parts; THRU 4-7 controls their forwarding.