Synth patch backup

Back up and organize Yamaha DX7 and FM synth patches on iPhone, iPad and Mac

Yamaha's FM synths send their sounds as SysEx: a single voice, or a 32-voice bank in one long message. Saved as files, those sounds can be sorted, recombined and sent back from a phone, tablet or Mac. Here is the routine with Syxloom, our SysEx librarian.

Which FM formats Syxloom reads

Syxloom shows patch names for these dumps. Support is based on published MIDI specifications; layouts from community documentation are labelled in the app.

  • Yamaha DX7 single voices and 32-voice banks.
  • Yamaha TX81Z, DX21, DX27 and DX100 voices and 32-voice banks, and TX81Z performances. On DX100 and DX27 banks, slots 25–32 are marked as not stored by those models.
  • Yamaha reface DX voices, whose several blocks are kept together as one library entry.
  • Korg volca fm2 programs (community-documented layout, labelled).
  • The Korg volca fm and volca fm2 receive DX7 voice and bank data, so DX7 entries list them as compatible destinations. The original volca fm cannot send dumps, so keep its banks as files.

Before you connect

Syxloom uses Apple's CoreMIDI, so a USB or DIN MIDI interface or Bluetooth MIDI works. Keep the app open while capturing or sending; switching away stops the current operation.

Check the instrument too. The DX21, DX27 and DX100 exchange bulk data only with SYS INFO on, and accept a bank only with MEMORY PROTECT off. The TX81Z answers only on its basic receive channel. The reface DX reportedly needs "MIDI Control" on to reply (community-reported).

1. Capture a dump

One catch: the original DX7 (Mark I) is widely reported not to answer dump requests, so send from its front panel (FUNCTION 8, SYS INFO AVAIL, then MIDI TRANSMIT?). The TX7, DX7II/DX7s and TX802 are reported to answer. Both are community reports.

  1. Open Monitor and choose the MIDI input your synth is connected to.
  2. Start the dump on the instrument, or send a request preset from Devices (DX7, 4-op, TX81Z or reface DX). Presets use MIDI channel 1; for another channel, paste the request as hex in the Library and send that.
  3. Wait for the capture to show as complete. Stalled or aborted captures are marked, and a damaged one is never read as a patch.
  4. Save it to the library with a name you will recognise.

2. Read the names and check the data

The inspector lists the patch names and checks framing, length and checksum. A DX7 bank and a 4-op bank are both 4,104 bytes; Syxloom tells them apart by the header's format byte, never by size. A name with non-text bytes shows as "(name not decoded)" rather than a guess.

Yamaha's checksum byte makes the data and checksum add up to a multiple of 128, so a byte changed in transit shows as a mismatch. Repair checksum saves a corrected copy, but it cannot restore a damaged byte; capture again when you can. A dump missing only its checksum byte (a 4,103-byte bank, say) is explained and can be saved as a corrected copy.

3. Organize the library

Tag entries, add notes, star favourites and search with several words (every word must match a name, tag, note, model or patch name). Find duplicates spots identical files and DX7 voices repeated across banks.

4. Build a 32-voice DX7 bank

A DX7 bank is also the format the volca fm and fm2 receive.

  1. In Bench, open Patch tools and choose the DX7 Bank Builder.
  2. Pick voices from anywhere in the library, including inside other banks. Empty slots get INIT VOICE.
  3. Save. The new bank gets a calculated checksum; source entries are untouched.
  • The volca fm display reportedly shows 8 of the 10 name characters (community-reported); the Bank Builder flags longer names.
  • A volca fm2 program can be saved as a DX7 voice; the fm2-only settings are dropped.
  • There is no 4-op bank builder: TX81Z and DX100 banks can be stored and resent, not assembled.

5. Send it back with pacing

Every send goes through Review transfer, which shows the destination, the messages in order and the gap between them; nothing leaves until you confirm. A saved pacing profile is reused for that instrument.

Yamaha and Korg publish no timing for these, so Syxloom's gaps are labelled suggested: 150 ms for a DX7, 100 ms for 4-op models, 50 ms between reface DX blocks, 500 ms after a volca fm bank.

A gap applies between messages, and a bank is one message (about 1.3 seconds over DIN MIDI). Some USB MIDI interfaces are reported to drop volca fm banks; a DIN interface is the suggested fix.

The receipt shows your device delivered the bytes, not that the instrument stored them, so check the sounds on the synth and keep the original file until you have.

Where Syxloom fits

Syxloom is our SysEx librarian for iPhone, iPad and Mac; one purchase covers all three. Its format support is based on published MIDI specifications, and layouts that come from community documentation are labelled in the app. It has been tested on simulators, with a virtual MIDI harness on the Mac and with large generated test libraries, not with physical instruments, and it cannot confirm that an instrument received or stored a patch.

Syxloom is also sold with Midiary, our Standard MIDI File studio for iPhone and iPad, in the MIDI Toolkit bundle on the App Store.

New to SysEx? Start with What is MIDI SysEx, and how do I back up my synth?.

The app in this guide

Every app here is one we make. This guide is checked against the live catalogue each time it changes — if an app named here ever left the store, the build would drop it rather than link to nothing.

Yamaha, DX7, TX81Z, reface, Korg and volca are trademarks of their respective owners. Instrument names are used only to describe compatibility; Shadowfetch is not affiliated with or endorsed by Yamaha or Korg.

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