MidiALF

MidiALF is an 8 step DIY friendly MIDI/CV sequencer with 40×2 LCD, 8+2 clickable rotary encoders, 8 LED switches and 8 tactile switches.

MidiALF_in_acrylic_case

MidiALFCV_naked_(small)

MidiALFCV_done_(small)

Manual

Build instructions

Troubleshooting

Ordering

Latest firmware: midialf_201

Features

8 steps in 4 sub-sequences which could be linked as two 16 step sub-sequences or one 32 step sequence.

Each sequence contains 10 tracks:

  • note/mute
  • velocity/skip
  • gate/legato
  • CC1/send
  • CC2/send

Sequence direction: forward, backward, pendulum, random.

Nonlinear sequence progression modes (same as in MIDIBox SEQ v4):

  • forward, backward, replay
  • interval, repeat, skip

Conditional triggers for Note, CC1/2 and re-trigger, similar to the ones in Elektron’s RYTM and Digitakt. No more static sequences, spice it up periodically, randomly or manually by pressing the SHIFT key!

Note, Velocity, CC1/2 randomization. Note value can be randomized according to a selected scale which can be different for each step of the sequence. Try mixing different scales in the same sequence, endless joy!

Note re-triggering, 2-16 per step, velocity and pitch modulated, chromatic or restricted to a selected scale. Also can be conditionally triggered. Now you can ratchet just like TD.

Song mode: up to eight steps, each specifies the sequence to play, how many times and at what transposition.

Sequence and step randomization using 167 music scales (thanks to MIDIbox.org).

Real-time and step recording modes: records notes, velocity, legato and CC1/CC2 values.

Two assignable CC LFOs with the period of up to 2 bars and sync to start, sequence and step in addition to free running.

Internal storage for 64 programs each containing 4 sequences with setup parameters and 16 character name.

Sysex send/receive of sequence, program or all programs.

Remote control with CC.

Super stable internal clock based on Mutable Instruments MIDIpal technology, 25-250 BPM.

Optional CV extension board: adds 4 x CV an 4 x Gate outputs.

Firmware upgradable by SysEx.

Midi only variant is powered by external 7.5 – 9V DC power supply, center pin positive, minimum 300mA. MidiALF/CV variant needs 16VAC AC power supply.

DIY Resources

Schematics: alfsch#1 alfsch#2 alfsch#3

MidiALF_brd

Bill of materials.

Source code: midialf2_src

PCB and MCU

You can purchase MidiALF main board directly from me for US$35.00 and pre-programmed ATmega644p MCU for US$15.00. The CV extension board is US$30. The prices do not include shipping from California, USA. PayPal payments only.

Case

[to be announced]

MidiALF_plexi

Acknowledgements

MidiALF is built around technology developed by Mutable Instruments: most of its hardware components can be found in various MI’s projects (mostly Shruthi-1 and Ambika), while software implementation uses quite a lot of code from MIDIpal. Not to mention the breakthrough Avril programming framework that brought modern C++ programming (read: productivity and sanity) to Atmel MCU world. Without this MidiALF project would not be possible, so thank you, Olivier, for sharing your talent with all of us!

I’d also like to thank Thorsten Klose of MIDIbox.org for his kind permission to use music scale definitions and non-linear sequencer progression modes found in MIDIbox SEQ v4.

MidiALF v2 Conditions are fully modeled after famous Elektron’s Trig Conditions. Whoever invented them at Elektron is a genius. This invention made the whole concept of sequencing a lot more interesting musically. Thank you, Elektron!

264 thoughts on “MidiALF

      • Looks great… LCD connector seems to be on the wrong side though. If you don’t have rework station the best thing to do is to sacrifice the connector: cut the plastic and remove pins one by one.

  1. finished midiALF DIY step sequencer

    Pete, you’re totally right! That was my roadblock yesterday. Above photo shows the problem solved with desoldering braid and patience. No damaged pads and I reused the header!

    Lesson learned, though 🙂

    MidiALF plays very nice with Shruthi! Some interesting effects when you tweak the arpeggiator on the Shruthi while using the sequencer. I can’t wait to start integrating this into my setup more! The startup LED animation is so classy, also!

  2. @kvitekp, do you have plans as to how the CV board and jacks will be mounted? And how many/what they output, for that matter?

    I’d like to get a case going soon so I can comfortably use this in my live performance rig!

    • CV board is sandwiched to a main board sing the stand offs you have, exactly the same method in Shruthi.

      CV board is not yet routed, however 1/4″ connectors layout is final and Frank has Eagle files for it.

      CB board connectors are: 4 x CV, 1 x Gate and 1 x Strobe or Clock.

  3. It’d be neeto to add either space along the top or to the side of the case for panel mounted CV/Gate jacks and just wire em to the PCB. I feel the rear mounted option will be a bit cumbersome.

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  5. Hi Pete – I’m trying to figure out how to play midialf in 7/4 time – i.e. reset after step 7. Is there a simple way of doing this? I couldn’t find anything in the manual.

  6. I can’t fully understand if this sequencer controls one instrument at a time, or if it can sequence various midi channels at the same time, each with it’s own pattern.

  7. Hey,
    Is it possible to order MidiALF and MidiBUD programmed MCU with a little modification?
    I mean my own welcome text on the display.
    Is such a modification would be possible for the price of programmed MCU, or requires an additional fee?
    Cheers!!

    • Pre-programmed MCUs are programmed in bulks, and what you request requires a custom build and flashing.

      You can easily do it yourself — the code is published, so you can build and upload the modified firmware. The welcome string mode does not require any programming skills, it’s just a string change.

      BTW, MidiBud does not have a welcome string.

    • you can chain sequences together, so you have 4×8, 2×16 or 1×32. There is no automatic switching between programs in the current firmware. Future versions may implement “Song mode”

  8. I am really intrigued by the LFO with CV out, it has been really difficult to find MIDI synced LFO that outputs CV. Is there any possibility that the LFO parameters could be controlled by MIDI CC? Could this be added to the firmware in the future? Automating LFO this way would be a dream.

  9. I just bought a MidiAlf eurorack converted.
    The first this that really bugged me up is that when i link 2×16 there is no way i coud stay on one of the 8 step. This make it very hard to edit on the fly.
    That problem only make me very upset about the usability of this sequencer.
    Is this something someone could fix with a firmware update ?
    Until then the Midialf is going to be toss away.
    😦

  10. Hi Pete, do you think -drum mode- like in MidiBox could be easily implemented? (symbols instead of notes per step). Looking forward to get v2.0 . Thanks!!!

  11. hello pete !! i have a semi modular synth, i want to conect it to a keyboard and to a sequencer too . can i use the midialf cv to do that ? or i need a converter midicv before conected to the sequencer ? i hope understand me thanks you!

    • MidiALF/CV is a sequencer and a 4 xCV/4xGate Midi2CV converter in one device. I use it between MIDI keyboards and my modular and semi modular synths all the time.

    • Intl shipping you paid for does not include real tracking — just the fact that the package is on the way. I’m not sure how long it takes to arrive in you country, i would give it at least two weeks.

    • Diego, it’s on the way, give it some time. You order has been shipped 10 days, i’m not sure how much time it takes for package to arrive in your country, but give it at least two weeks.

  12. One thing that would be useful would be to be able to assign any of the 8 output jacks(4cv, 4gate) to either cv or gate so you can customize(6cv, 2gate for example). Are there any hardware limitations to this? How hard would it be to alter the firmware?

    • This is not technically possible because gate outputs are very different from CV outputs electronically. CV output could work as a slow gate through, but certainly not the other way around.

  13. Does anybody know of a UK source for a 16V AC adaptor for the MidiAlf CV board?
    I can find 15V ac or 24V ac, the only 16V one I can find is US sourced.

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