Deimos - free synthesizer (Windows, MacOS, Linux)

[onerob]

Just did a quick test and it's now validating

And the cursor is hidden for me, at least on my initial quick test.

[onerob]

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[onerob]

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[Tom Trnk]

Just did a quick test and it's now validating

And the cursor is hidden for me, at least on my initial quick test.

Okay, very odd that the cursor isn't behaving on my side then .. but good to hear it works for you! Enjoy!

[Tom Trnk]

To be future save, I would actually go the CLAP route. Its pace is way faster than VST3 back in the day, and according to Urs U-He, they get things faster done since they base all their code on CLAP in the first place, and then wrap them for VST/AU/AAX… which all only support a part of the features of CLAP. First of all per voice automation, which is crucial for expressive MPE playing…

Right, basing the code on CLAP and wrapping it for other formats seems like a sensible approach at this point. The framework I'm using was around before CLAP was a thing so it does things differently ..

So I still have to figure out how to get some MPE support going across different formats. Got a LinnStrument a year ago also for that purpose, but didn't get very far with that yet. Now that most other stuff is quite stable, I hope I can again look into it soon

[Tom Trnk]

Had to have a little break .. but there's a new update available now: Deimos 0.8.0

It comes with some bug fixes and adjustments, details in the devlog.

A small feature addition also made it in: Ring modulation!
Right-clicking the "Osc 1"/"Osc 2" buttons in the mixer will reveal an option to enable it.

More updates coming soon!
Enjoy

[jmonzani1]

I've just discovered this plugin and everything is smooth and well! (Windows 11 with Reaper). Looking forward to see what will come up.

[MaZe 6000]

Oh yes, this one is really good!
Lots of good ideas in a compact package, great features in a great interface, and most importantly great sound!

Thank you!
(Running CLAP in FL Studio on Win11 - no problems so far)

[Tom Trnk]

Happy to announce I finally got around to implementing support for polyphonic expression

New update available here: Deimos 0.9.0
Details in the devlog

Enjoy!

[Chris-S]

Filter has some "bump" in the Attack phase ?

Sawtooth with LP4 filter:

Screenshot 2026-04-15 145104.png

[Chris-S]

Do I see right that the OSCs do not have a free running (phase) mode?

[Tom Trnk]

Do I see right that the OSCs do not have a free running (phase) mode?

The oscillators are actually free-running by default.
They stop being free-running as soon as the "slop" control is turned to zero and there is no detuning between the oscillators, apart from very stable relationships like whole octaves for example. At that point, the oscillators for fresh voices should have a consistent phase relationship.

Filter has some "bump" in the Attack phase ?

Hah, it's been a while since I looked so closely at the synths output
Is your screenshot showing the onset of a note only? What other settings have you been using?
So far I haven't been able to reproduce something like in your pic .. but I can say that there is a little trickery going on with the filters attacks to help with certain resonance settings.

I found that there's a bit of DC that can leak through after the amp envelope finishes very fast. That's basically inaudible on its own but can only muddy up a mix, so I fixed that on my side. Will be in the next update if it plays nice!

[Chris-S]

All settings in Default basically.

The bump ist not consistend (different on every Note start). And it's audible on good speakers.

Phase: you say the Oscs are free running, but what ist the Phase knob doing then?

[Tom Trnk]

The bump ist not consistend (different on every Note start). And it's audible on good speakers.

Hmm yes, based on the picture I'm sure this one is audible
Thanks for the picture, I took a closer look again and my best guess so far boils down to partially overlapping midi notes, which could happen with a slightly jittery/quirky midi controller or some weird midi routing setup?

I guess overlapping notes because the peak of the bump doesn't line up with the others if the note you played had consistent pitch, and also because the synths amplifier section does some post-envelope compression/limiting so at default settings a single voice couldn't really produce such a bump.
If my guess is right, setting the synth to monophonic or enabling the "realloc" switch in polyphonic mode should prevent the bump.

Which OS + DAW + plugin format are you using? And can you reproduce the bump when manually clicking notes into a piano roll?
Apparently some DAWs might give a plugin different inputs when live playing vs playback of recorded midi, so there could be a few different situations to investigate

I would of course also be happy to take a look at your recorded midi to confirm or rule out my guess of overlapping notes.
I think I'll have to add some sanity checks for that possibility either way into my synth.

Phase: you say the Oscs are free running, but what ist the Phase knob doing then?

The phase knob mostly becomes relevant when combined with the waveform modifiers options found to the right of the waveform selection. How they behave often depends a lot on the phase setting. The phase also interacts with oscillator sync, and of course it can also be used as modulation target.

[Tj Shredder]

Happy to announce I finally got around to implementing support for polyphonic expression

New update available here: Deimos 0.9.0
Details in the devlog

Enjoy!

VST and CLAP don'tvalidate in Bitwig 6.0.2:
com.bitwig.flt.library.metadata.reader.exception.CouldNotReadMetadataException: could not read metadata: Plugin host did not respond for 20.0 seconds
I just see there is a newer Bitwig version, will try later if that solves the problem...