signaldust

Dolphin bassline

[Dolphin screenshot]

This little monophonic synth is a proof-of-concept toy inspired by a well-known silverbox from the early 1980s. Empasis is on "inspired" as calling it a model would be something between a joke and a lie. It should still do techno.

It has an oscillator, which you can ask to output either saw-waves or square-waves. The output of the oscillators goes into a variable frequency filter with optional resonance. Finally the output of the filter is multiplied by a slow, fixed-time envelope. Tweaking the knobs is suggested.

The oscillator will simply track the latest MIDI note-on message, so you'll probably want to sequence it. MIDI note-off messages matching the current note will gate the amplitude envelope. Overlapped notes won't retrigger the envelopes, and will cause the oscillator to slide to the new pitch. Notes with high velocity (about 101 and up) will trigger "accents" (these can be sliding notes too, or even half-way through the same note if you manage to convince your host not to send note-off in the middle), which will temporarily set the filter envelope timing to minimum and depending on the accent knob (and for slides also the remaining level of the filter envelope) boost volume and cutoff a bit (but see here).

Other than the tuning and accent knobs, the rest of the knobs conspire to modify the behaviour of the filter in somewhat chaotic way. In theory the cutoff will manually change the cutoff, the resonance will improve the filter quality factor, the env mod will control how much the filter envelope modifies the cutoff and the decay will change the decay time of the filter envelope.

You can listen to some pointless knob tweaking if want to, but hopefully some of the example patterns (included as MIDI files in the download) are a bit less awful.

Download Dolphin (requires processor with SSE2!)

Warning: version 1.5 changes the patch format (old patches should still load, ultimately depending on the host you are using; proceed with caution).

Version 1.5 also sounds slightly different than before.

Responses to be given frequently

  1. It doesn't sound like a 303! 

    It's not an emulation, nor will I care to make it so. The filter and feature set are somewhat similar but that's it. Get one of the existing emulations if you want something that claims accuracy.

  2. The GUI is awful!

    Don't you dare to comment on my drawing skills! This is personal. Now I must challenge you to submit a better looking drawing of a dolphin (if anyone does, I'll promise to post 'em here for the fun).

  3. Why does it use so much CPU?

    It uses 5 times oversampling and a slow method of solving the filter. It is designed for modern computers.

  4. Could you make it not require SSE2?

    Yeah, but I won't, because then you'd just complain about the CPU usage next (or alternatively get angry because your pride prevented you from complaining when I said you would). Really.

  5. What about MIDI CC support?

    Versions from 1.5 up (those with new knob-images) can learn CC; right-click a knob.

  6. What's wrong with the square?

    Not much. It's pretty standard band-limited squarewave, with very slightly unequal pulse-width and a bit of noise. The band-limitation isn't perfect, but together with the oversampling the aliasing shouldn't reach audibility. You probably wanted to ask the next question.

  7. What's wrong with the 303 square?

    As far as I can tell it's just really crappy. I like the sound of good square waves, so I care not to try to model what makes that particular square wave crap in that particular way. YMMV and see here.

  8. It has too much/little bass (or other sonic features)!

    I tuned that to my personal taste (along with the frequency dependancy of the resonance and the way the resonance distorts, all three of which are inter-related). As far as the bass goes, you can use some EQ if your taste is different.

    Note that the sound changes quite significantly in version 1.5, most obviously affecting the bass.

  9. The accents sound "wrong"! 

    They are largely a hack. There is a small possibility that I will change the accents in the future, but in that case I will probably make them a lot slower (in other words: less like the silverbox).

  10. Why make a stupid synth like this?

    Why not? It was a good learning experience.

  11. Could you make a Mac version?

    No.

Changelog

1.5.0: migrated to use new framework (knobs, MIDI CC, new patch format, etc) and retuned filter response

1.0.0: first public release