Sequential Prophet Rev2 – undocumented special menu

The Prophet Rev2 features an undocumented special menu. Besides other things, it allows to copy user banks to preset banks (and the other way around). A very handy feature in case one wants to host other than the factory patches in the “ROM” preset banks.

To call the “debug” menu, just press the buttons down, up and global simultaneously.

Get the duration of a couple of audio files

I wanted to know the total duration of a couple of mp3 files, using onboard tools of a Mac. Thanks to StackOverflow, it’s as simple as:

find . -name "*.mp3" -exec afinfo {} \; | awk '/estimated duration/ { print $3 }' | paste -sd+ - | bc | awk '{printf("%d:%02d:%02d:%02d\n",($1/60/60/24),($1/60/60%24),($1/60%60),($1%60))}'

Obviously, I could have figured this out in a couple of seconds by reading some man pages. But searching the web was even more convenient. So I leave it up to you to figure out what exactly the above commands are doing. Alternatively, just use soxi :) .

Sequential Prophet Rev2 startup sound

The Prophet always is loading a certain patch when booting. Unlike other instruments, it does neither remember the last used preset nor start with the sound of the very first memory slot. Instead, the user can actually set up the sound to load the following way:

  • Select the preset the Prophet shall load at startup.
  • Enter global menu.
  • Leave global menu.

That’s it.

Modulation matters

Modulation is a key ingredient to synthesizer sounds. Modulation adds movement to the sounds, making them less static. Common modulation techniques include envelopes to shape the volume and partials over time, low frequency oscillators (LFO) to periodically alter the pitch of oscillators (vibrato) or the volume of the sound (tremolo), or velocity to add volume or brightness to notes played harder than others. Advanced synthesizers provide a modulation matrix which allows to route modulation sources (like the ones mentioned above) to various destinations.

As a rule of thumb, the more modulation capabilities exist, the more different sounds can be produced by a synthesizer and the more complicated it is to understand and use. As a consequence, some synthesizers are designed focussing on the quality of the basic building blocks (oscillators, filters) and provide little modulation capabilities (e.g. one LFO only synths like the Korg prologue and minilogue xd or the DSI/Sequential OB-6, for which Steve Hunt offers a “Low Frequency Expander for OB-6” breakout box).

When it comes to LFOs, it’s not only the amount that matters, but also the waveforms provided. The Korg prologue and minilogue xd’s LFO just provide three (saw, triangle, square). More advanced LFOs may also provide Random/S&H waveforms. A waveform seldom to find is Sample & Glide, which provides a less stepped random waveform. It can be found, for example, in the Korg Z1 (four LFOS) or emulated in the John Bown Solaris (four LFOS) by routing the S&H waveform through a lag processor (actually a low pass filter). This waveform allows for very subtle, unobtrusive modulations.

The abovementioned Korgs just provide one LFO with three wavefroms only. Additionally, the single LFO can only be routed to one destination at a time (pitch, shape, cutoff). This design is pretty straightforward, and the panel controls give the musician immediate access to the modulation. While I’d like to congratulate the designers for resisting the temptatoin to add more, I perceive the design as very limiting.

At the other end, there are synths (like the Access Virus or the Sequential Prophet 08) which provide both multiple LFOs and a modulation matrix. One can create a lot of very interesting sounds with them, but without reading (and understanding) the modulation matrix menu entries it is difficult to understand how a particular sound was designed. But anyway, the sounds of analog machines with modulation matrix are much sought after, as the still popular Oberheim Matrix-1000 proves.

The original Waldorf Microwave I, known for its extremely punchy envelopes, provides two special parameters for the LFOs. The first one is “Symmetry”, which has a special effect on the sine wave.

The second one is “Humanize”, which adds random variations to its rate. The Microwave also is known for its extremely flexible (and even loopable) third “Wave envelope”.

Admittedly, I’m a big fan of all kinds of weird modulation capabilities and can spend hours exploring what sounds can be achieved using them. On the other hand, machines limited in modulation are interesting as well, as I pay more attention on the details of the limited capabilities, which fosters creativity, as Kebu states.

This entry was posted in Uncategorized on by .

Updating the firmware of a Korg prologue

As with the minilogue xd, the prologue updater tool asks to consult the user manual for details how to boot the synth into update mode. Unfortunately, neither the german nor the english manual contain the information required. It’s simple. Just hold the buttons six and eight while powering the synth on and wait until the display reads as “Version Up Mode”. Just upgraded mine from 2.0 to 2.1.

This entry was posted in Uncategorized on by .

Korg prologue and minilogue xd – Using liked programs aka favorites

Both synths provide a favorite system. Unfortunately they work differently and are hard to remember in case you only use them every now and then. So here’s a quick reference.

minilogue xd

You can register up to 16 favorites using the panel buttons:

  • Select the program you want to register.
  • Hold the Shift button.
  • Press the button which you’d like to serve as a shortcut to this program for about a second or so.

To recall:

  • Hold the Shift button.
  • Briefly press the button which represents the desired program.


To “like” or “unlike” a program:

  • Select the program you want to “like”.
  • Press button 4 for about a second or so.

To scroll through liked programs:

  • Ensure button 4 is lit.
  • Turn the Program/Value dial.

To scroll through programs by category:

  • Press button 2 multiple times to select the desired category.
  • Turn the Program/Value dial to scroll through the programs of the selected category.

To return to “normal” scrolling behaviour by program number:

  • Press button 1.
  • Turn the Program/Value dial to scroll through the programs one by one.
  • Press button 1 multiple times to jump forward by 50 program numbers.

The prologue provides further sorting modes and a live set feature. See page 12 of its user manual for details.

This entry was posted in Uncategorized on by .

OB-Xd preset location

The OB-Xd, provided by George Reales via discoDSP (and source on GitHub), is an excellent virtual analogue synthesizer emulation. It is not only available as a plugin for several DAWs, but also as a standalone app.

VSTs store individual presets as FXP files, or collections (aka banks) of them as FXB files.

In case you have downloaded an FXB file and want to install it for use in the stand alone app on a Mac, simply place the FXB in

Roland Lopes an der Dubois-Orgel in Wissembourg


Wie Christian Robischon letzte Woche war heute auch Roland Lopes bereits zum dritten Male in Weißenburg zu hören. Auf ihn freue ich mich jedesmal besonders. Das liegt an an der Auswahl der Stücke, seiner Registrierung, seiner Spielweise und auch daran, dass er gerne Transkriptionen von Werken mitbringt, die man nicht so oft an der Orgel hört. Hatte er am 5. August 2012 und am 30. Juli 2017 noch Transkriptionen von Jean-Babtiste Lully im Gepäck, so gab es heute eine Traskription von Johann-Sebastian Bach und einige von Jean-Philippe Rameau, der nach Lully als der nächste bedeutende französische Barockkomponist gelten darf. Das Programm:

  • Johann Sebastian Bach (1685-1750) – Fantaisie en sol mineur (BWV 542)
  • Jean-Philippe Rameau (1683-1764) – Ouverture (Indes galantes)
  • Jean-Philippe Rameau (1683-1764) – Menuets (Indes galantes)
  • Jean-Philippe Rameau (1683-1764) – Musette en Quatuor (Platée)
  • Jean-Philippe Rameau (1683-1764) – Menuets en trio et en duo (Zoroastre)
  • Jean-Philippe Rameau (1683-1764) – Entrée (Boréades)
  • Jean-Philippe Rameau (1683-1764) – Passacaille (Hippolyte & Aricie)
  • Johann Sebastian Bach (1685-1750) – Largo de la 3ème sonate pour violon (BWV 1005)
  • Denis Bédard (*1950) – Suite du 1er ton (1993) – Plein Jeu
  • Denis Bédard (*1950) – Suite du 1er ton (1993) – Dialogue
  • Denis Bédard (*1950) – Suite du 1er ton (1993) – Récit
  • Denis Bédard (*1950) – Suite du 1er ton (1993) – Grand Jeu

Christian Robischon an der Dubois-Orgel in Wissembourg


Coronabedingt habe ich heuer die beiden ersten Konzerte (Hans-Eugen Ekert am 2020-08-02 und Michel Bouvard & Yasuko Uyama-Bouvard am 2020-08-09) der Vésperales verpasst. Umso mehr habe ich mich darüber gefreut, wie Christian Robischon, der schon am 30. August 2015 und am 26. August 2018 zu hören war, erneut das Potential des Instrumentes zur Geltung brachte. Das Programm:

  • Jean Adam Guilain (ca. 1680-1739) – Suite du second ton pour le Magnificat (1706) – Prélude
  • Jean Adam Guilain (ca. 1680-1739) – Suite du second ton pour le Magnificat (1706) – Tierce en taille
  • Jean Adam Guilain (ca. 1680-1739) – Suite du second ton pour le Magnificat (1706) – Duo
  • Jean Adam Guilain (ca. 1680-1739) – Suite du second ton pour le Magnificat (1706) – Basse de trompette
  • Jean Adam Guilain (ca. 1680-1739) – Suite du second ton pour le Magnificat (1706) – Trio de flûtes
  • Jean Adam Guilain (ca. 1680-1739) – Suite du second ton pour le Magnificat (1706) – Dialogue
  • Jacques Thomelin (ca. 1635–1693) – Fugue sur «Ave Maria Stella» I
  • Jacques Thomelin (ca. 1635–1693) – Fugue sur «Ave Maria Stella» II
  • Jacques Boyvin (1649-1706) – Extraits de la suite du Sème ton – Prélude
  • Jacques Boyvin (1649-1706) – Extraits de la suite du Sème ton – Basse de trompette et dessous de cornet
  • Samuel Scheidt (1587-1654) – Magnifikat 6 toni I
  • Samuel Scheidt (1587-1654) – Magnifikat 6 toni II
  • Samuel Scheidt (1587-1654) – Magnifikat 6 toni III
  • Samuel Scheidt (1587-1654) – Magnifikat 6 toni IV
  • Samuel Scheidt (1587-1654) – Magnifikat 6 toni V
  • Samuel Scheidt (1587-1654) – Magnifikat 6 toni VI
  • Nicolas de Grigny (1672-1703) – Extrait du Kyrie de la Messe – Cromorne en taille à 2 parties
  • Nicolas de Grigny (1672-1703) – Hymne Veni Creator – Plein Jeu
  • Nicolas de Grigny (1672-1703) – Hymne Veni Creator – Fugue à 5
  • Nicolas de Grigny (1672-1703) – Hymne Veni Creator – Duo
  • Nicolas de Grigny (1672-1703) – Hymne Veni Creator – Récit
  • Nicolas de Grigny (1672-1703) – Hymne Veni Creator – Dialogue sur les Grands Jeux
  • Michel Corrette (1707-1795) – Final du Magnificat en la majeur

Korg Wavedrum live – Hiromi, Jackson, Smith

Percussionists like the Wavedrum due to its dynamics. Accidentally I stumbled upon a recording of Hiromi’s Trio project, where Steve Smith uses it in a pièce.

The energy the three musicians put into their music is incredible, as is their choreography.

Zynthian, the fun synthesizer

Of course I bought the V4 kit immediately, despite it’s more a project for the cold and dark season.

It took the whole eve yesterday to assemble the hardware, despite the fact I luckily had all the tools required available. Unfortunately it didn’t boot. Though the LEDs on the Raspberry PI and the soundcard lit during startup, the screen just left blank. Today I tried the following:

  • Try a new and more powerful power supply, just in case it was to weak to power all the hardware and the screen (as it happened with another Raspberry PI ages ago). This didn’t solve the issue.
  • Recheck the wireing inside the box. Everything appeared to be fine. Reconnecting the cables didn’t solve the issue.
  • Recheck the firmware image used. Heureka. I used »«, despite the fact the page clearly states that releases labeled as “RC” should be more stable. I downloaded »«, flashed it using Etcher and the device did start up immediately.

I connected a MIDI keybed and started Aeolus, a pipe organ emulation, on the device. Everything just worked “out of the box”. Phantastic.

I’ll check wether everything works as expected during the next couple of days. For now, I’m extremely content, thanks to the great work of all the people involved.

Zynthian Update – Raspberry Pi 4

Ages ago I was part of the Linux Audio community, but eventually I was bored by all the fiddling around and left Linux alone. Well, not exactly. For the kids of a relative, I configured a Raspberry Pi with a USB breakout box to use it as a pipe organ emulator. But some time later, they did the same I did – they bought a hardware pipe organ emulation. And I’m still extremely content with the instrument.

The advent of the Raspberry Pi 4, however, again makes the platform interesting for audio processing. And Zynthian, an open source project, upgraded to it. The v4 kit is available for 325 €. Before diving into it, I recommend an article for v3 as well as the Zynthian wiki.

Should I buy one of those tempting gadgets? Well, probably :) .

This entry was posted in Uncategorized on by .

Corrente Italiana

This Courante, a popular dance during the baroque era, is attributed to Juan Cabanilles (1644-1712). One aspect of performing it is that one can use several registrations for the various parts. There are several recordings, of which I found the following outstanding.

  • Bartomeu Manresa performs on a mallorcan instrument. I love his registration, especially the soft ranks chosen for the second part.
  • Jan Willem Jansen also has chosen a soft registration for the second part.
  • The recording with Michal Jung allows to grab some hints for fingering.
  • Nathan Laube performs on a more modern instrument and plays the piece extremely fluent and with carefully chosen registrations.

Scores are available via the International Music Score Library Project, IMSLP.

John Bowen Solaris – Preset Bank 8

About 5 years ago I explored the synthesis capabilities of the Solaris by creating several sounds for it. Every now and then, I posted the presets at the user forum. Eventually John included them in the OS as factory preset bank 8. Frankly, I still feel honoured :) .

In case you own one of the later Solaris’, you should have the sounds on board already (Bank 8 program 0 should read as »Softy«). If you don’t, here’s the files I sent to John on Feb 15, 2015.

Solaris Bank 8 – Christoph Eckert – 2015-02-15