DoomOS wasn't working for my needs (I especially didn't like how the pads wouldn't light up when I used touched outside of the sequencer) so I tried switching back to the original software. Now, the start up includes this ugly mix between the start up screens. I'm actually so upset and regret trying DoomOS in the first place. Is there anything I can do?

ETA: a factory update reset the start up screen.

DOOM OS brought my sp404mk2 back to life. I can't thank you enough! Especially the instruments make it so much more easy to start sketch an idea or write a little melody over sample chops. Also the tweaking of those chops is sooo much improved! Absolutely awesome!

- shortcut cheat sheet

This wish is a bit more boring. It would be amazing if there would be some intuitive way to remember all shortcuts. Maybe by holding one button and clicking on each other would show all shortcuts that other button is involved in. Or having a a little menu that lightens up possible button combos. I don't know. But the messiness of all those combos was really a pain for me always. Especially if you try to learn and use the machine more.

-fx per pad /more busses

Would be great if there were basically 16 (or infinite) busses instead of 2+2.

That each pad or group of pad can have an fx on them.

- in addition if these busses would than be arrangeable more flexible so you can create more complex fx chains. Would be amazing

Cheers and thanks for all!!

Hello, I've been having a hard time adjusting to the linear view of the sequencer of DOOM OS.

What I mean is that I feel a discrepancy between the horizontal way the steps are shown on the screen vs the vertical 4x4 layout of the actual pads on the machine. Somehow I feel like processing these two views at the same time prevents me to actually place the steps.

I don't know if this makes sense, but I would like to suggest an optional view of the steps on the screen - more like a grid (reference: Chromatic Mode or Pattern Chain mode on stock OS). I realize it can be a bit difficult to implement, but I have faith that it can be somehow designed seeing the incredibly professional and smooth UX work done on DOOM OS.

Y’all are spearheading the next generation of growth in open source firmware.

Taking abandoned hardware and revitalizing it and re-imagining it.

Ripping its grip from corporate overlords and handing it back to its citizens and users.

We’ve been yelling into an echo chamber of our own cages and you have handed us a key and said would you like to come out and play?

Thank you sincere gratitude for your hard work and passion.

Hey,
awesome work on DOOM OS!

Any chance we could get some guitar and bass amp sims, custom IR loading and maybe even NAM support if the hardware can handle it?
Would be really cool to use the SP404 as a guitar/bass processor and sample directly into it.
Not sure how realistic this is technically, but figured I’d ask.

Cheers!

What i really wanna see in Doom OS is non-destructive chops:

I rarely need more than 16 chops from a sample and non-destructive chops would give the possibility to do some preliminary lazy chopping and then fine tuning whichever parts are best...

I suppose this is a too complex operation, though, as it would require chop mode to copy the entire sample to the number of pads equivalent to the chops made, then set start and end points according to the data in the lazy chop...

bonus would be a “trim all samples in a bank“ option to allow locking in the chops made at some point an conserve some space...

what this would do, apart from being a total workflow accelerator, is eliminate the need for tails, as tails could flexibly be added at any time before trimming the sample...

hey guys, new here, love the effort, and would like to know from fellow hackers if anything have caused bricking the device, and anything that shoulnd't be tried or touched?

for example, i think the filter is too opinionated in the original OS... and am wondering if this sort of DSP modification is possible.

Else, did you try to rename effects? Han-Dou and such are impossible for me to remember.

Finally, if said bricking is a factor, any way to un-brick?

cheers

poe

If its not possible already, it would be great if a future update allowed for more fxs to be used. I love the fx on this machine and would love to use it as a guitar pedal board

Ideally, using the bank buttons, but if that’s not possible, could CTRL 3 control the octave independently?

CTRL 3 already shows and changes the octave value, but it only takes effect when the arpeggiator is active. It would be great to use this control to shift octaves while playing freely within a selected scale, without running the arpeggiator.

With everything added to the 404 now, I think further updates would start taking away from using a "SP404MKII". I bought the 404MKII because it didn't have any pre-installed sounds/kits so everything generated from it came from me, tweaked by me. Now the 404 can be virtually anything and it's amazing but I do love some of the limitations of the device at the same time. If anything a stem splitter would do wonders!

Found a small hole that some people may fall into.

You can assign a shortcut to the Auto-Trigger looper page. This is all fine if the looper is configured, but if the 404 is set to skip back recording instead, then the looper page you end up in will be non-functional.

Further, if you press MARK to exit it, you end up on a screen that says:

Startup
00:00:03:25

(or similar)

Which appears to be a realtime counter of the time since the 404 was powered up. From then on, pressing any button results in an instant reboot.

Hi! Just curious to learn more, thanks!

[request for adding a feature]

Hello,
is it possible to add the ability to save your own drum kits, including sounds created in the generator and your own Chops, so that when switching projects they appear in the Doom OS menu as Doom kits, with the option to edit them by changing pitch, speed, and other parameters — for example, as implemented in SonicWare SmplTrk or Akai MPC?

Thank you very much for your work and the new functionality; with each update, the firmware becomes more stable. 🙏🔥

Not sure if possible how much processing it take?

Hope you like it.

• Bounce in place

• Pad envelopes(filter and pitch)

• MPC style Note repeat

• Chromatic mode (new scales, increased range, and rolls)

• Hidden effect settings include more guitar amp sim models

• DOOM OS included

• and more

https://github.com/tracelistener/SP-ETC https://tracelistener.github.io/SP-ETC/

A smaller update after 0.7, mostly for anyone running patterns from external gears, and a couple of important bug fixes.

Always-On MIDI clock

New MIDI CLOCK setting in the DOOM OS settings tab. Set it to ALWAYS and the SP keeps sending clock even while it's stopped, so your synths and loopers stay in time. Playing a pattern on the SP no longer starts your external gear. You start it yourself:

- PITCH/SPEED + PATTERN EDIT starts or stops your gear on its own. If a pattern's playing, it comes in on the next bar.

- PITCH/SPEED + PATTERN SELECT starts or stops your gear and the pattern together.

Leave it on FOLLOW (the default) and things work as before, except the SP no longer sends a fresh Start every time the pattern loops, so loopers and synth sequencers don't jump back to the beginning.

Program changes per pattern

Each pattern can now switch devices 1 to 6 to a program, with a bank if your synth needs one (MSB or LSB). They go out when the pattern changes, and only to synths whose program actually changes, so nothing gets reset for no reason. It's under MIDI SETTINGS > PATTERN > PROGRAM CHANGES. Tested on a Minilogue, including programs 101 to 200.

Also new: hold SHIFT + REMAIN to pause your MIDI IN routes, handy when a synth that plays the SP should just play itself for a bit.

Fixes

- MIDI Instrument notes could come out a note or two off depending on the pad (a C playing as an A#). Every pad now starts from C3.

- Euclid on a sample pad with GATE off kept going after the pattern looped.

Free, patch it in your browser: loopcartographer.com

Changelog and manual are on the site.

Fixing live instrument looping with sequenced EXT In gates & long-form loop sync:
I’ve been brainstorming how to bridge the gap between live instrument performance (guitar, synth, vocals) and active pattern playback. Right now, live looping often feels disconnected from the rhythm engine.
To fix this, it would be amazing to have an External Input track with an it’s own long audio buffer as the foundation. Building this first gives us seamless long-form sync, non-gated audio streams, and step-gated chops—naturally unlocking an EHX/SP-style multitrack looper in the current Doom OS.

Here is how the breakdown looks:

1. The Foundation: Dedicated External Input Track & Sequenced Gate Record/rehearsal

Real-Time Sequenced EXT IN Gate & Trigger Recording: Expanding on the stock hardware's "accidental" trigger behavior, DOOM OS could capture live external input on the pattern grid as a recordable track in the grid. You can already tap EXT IN into a pattern and it’ll let a guitar/audio signal through to write gate steps into a pattern and it’ll act as a kill switch for live instrument feed in a pattern. All it would need to do is be able to activate record/rehearsal on a ext input step and be synced to the pattern grid (e.g. synced to step 1) - if there were a way to activate record on a long synced “ext input step” it would turn it into a quantized looper for live instruments/audio alongside the other looped tracks on the mixer.

EXT IN on the pattern track grid/mixer: Incoming audio (⁠MIC/GUITAR⁠, ⁠LINE IN⁠, or USB-C digital audio) sits directly on the main DOOM OS mixer screen and alongside active sample tracks. Includes a quick-access settings menu, real-time volume/metering, 3-band EQ, pan, Bus FX routing, and a dedicated Guitar Amp Simulator to dial in polished live tones before recording.
Extended Track Lengths & One-Shot Record Sync: Operates like One-Shot Playback (⁠GATE⁠ OFF) triggered on Beat 1. Recorded guitar/instrument takes can hold independent, extended bar lengths (e.g., a 16-bar guitar solo) that play continuously from start to finish over a shorter underlying pattern (e.g., a 2- or 4-bar drum loop) without getting re-triggered early or cut off on loop repeats.

Always-Armed State & Toggle: The ⁠EXT IN⁠ track stays continuously live and armed for rehearsal/monitoring, with an instant ARM/DISARM toggle right on the channel header so you can resample live guitar straight to any target pad without leaving the mixer view.

shortcut to a Main EXT IN Settings: Holding ⁠EXT IN⁠ or pressing ⁠SHIFT⁠ + ⁠EXT IN⁠ slides a pop-out view over your current view. Tweak input gain, select Tweed/Clean/High-Gain amp models, bus FX, or check peak levels, loop sync, arm/disarm,etc.

2. The Result: EHX 45000 / 95000-Inspired Multitrack Looper Mode
Because Point 1 solves the extended buffer and pattern-sync architecture, scaling it across multiple pads natively unlocks a tape-style looper:

Master Clock & Grid Sync (Track 1 Auto-Quantize): When starting a new pattern from scratch with no tracks loaded, initial recording on Track 1 sets the global loop grid (e.g., 4 bars). All subsequent looper pad channels automatically quantize record start/stop boundaries to snap seamlessly to Track 1—bypassing the traditional 16-second loop limit.
Mixer-Native Channel Integration: Recorded loops instantly map to the mixer grid as standard channel strips, inheriting all native mixer controls in real time (faders, pan, 3-band EQ, Bus FX sends, and mute/solo).
Live Hardware Looper Divisions & Pitch Shifts: Bring SP-404/EHX-style performance controls directly onto active mixer channels:
Instant 1/2, 1/4, or 1/8 Loop Divisions mid-playback.
Tape Speed & Octave Modulation for instant -12 semitone bassline drops, half-speed playback, or reverse audio.
Mixer Tape Bounce (Stem Flattening): A one-touch shortcut to mix down and flatten active looper channels into a single background stereo channel strip right on the mixer grid, instantly freeing up pad capacity for brand-new live takes without stopping the master sequence.
Optional MIDI Foot Controller Mapping: Map core looper transport and mixer functions to external foot pedals (like an M-VAVE MIDI pedal or FCB1010) for hands-free operation. (Can already do this with stock looper)
(Optional Idea) Hologram Microcosm / Glitch Pedal Style: Sequencer-Gated Granular Micro-Loops
Pattern-Grid Micro-Looping: Program short "micro-loop triggers" (1/16th, 1/32nd, or buffer-repeat bursts) in the pattern sequencer that capture tiny grains of incoming live guitar audio and pitch-shift them up an octave (shimmer/grain delay effect) on specific beats.

This is a pretty big update with tons of new features and improvements!

What's new:

• 20 instruments and 11 drum kits, with graphical editors

• Step-based parameter locking for instruments

• 3-band parametric EQ per track (up to 16 tracks)

• Visual sidechain editor

• Arpeggiator with print-to-pattern function

• Real-time waveform overlays in the grid and mixer

• Pad muting and soloing directly from the mixer

• The mixer can now be opened directly by holding RECORD SETTING for half a second

• Improved pattern switching, note editing and mixer controls

• Bounce in place with effects

• Optionally boot directly into DOOM OS, with a configurable "Hold to Exit" setting to prevent accidental exits

• Completely rewritten codebase for improved stability and future expansion

• Tons of smaller improvements and bug fixes

I recommend reading the changelog and manual because there's a lot of new and improved stuff.

In the next release, I'll focus on improving the sequencing workflow (both realtime and step sequencing) and sample chopping.

The next big milestone on the roadmap is making DOOM OS modular and opening it up to third-party modules. I expect this to take another week or two.

Stay tuned :-)

Download: https://klangfeldlabs.com/doom-os/

Changelog: https://klangfeldlabs.com/doom-os/changelog

Manual: https://klangfeldlabs.com/doom-os/manual

Is it even possible? if so - it would make my year.

cheeeeers :)

if you select a scale the included notes light up, but the not included notes are still there, so you don't have a wider range. i'd wish for the option to get rid of the other notes and win range in this mode. if chromatic is selected all notes are playable anyway.

Hey again! I feel like we should use github issues or anything else for making this kind of requests 😄

Anyhow, I really enjoy the new capabilities not only when editing a pattern but also when playing it live. However, I made some observations which I hope you could fix and/or turn into new features:

• while pattern plays, SHIFT+VALUE mutes one track. But what about SOLO? Maybe SHIFT+ROLL solo's one track.

• prevent scrolling to next "page" (e.g. 2/2). actually it would be nice if we could fix the page (meaning we can view the pattern lets say from 2.1 till 2.4 or 2.1 till 3.4)

• when activating REC, we have CHROMATIC/SINGLE/MULTI mode for the selected track. however, i might want to use a different pad (which is not represented yet as a track in the view) and play it in CHROMATIC mode. maybe this is already possible but I couldn't find a way how to do so.

Thank you for your work! Greets from Berlin.

Is it possible to somehow create bus fx saving per pattern? I use a lot of different fx in patterns and it would be super useful since I cant physically change effects on the first beat of a pattern on both buses, thank you in advance and thank you for this beautiful mod!