Neutron Sound

Orgone Accumulator


Default Title - $360.00

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The idea of this is to be cheap and not use much more than a Teensy 3.1 and some op-amps and controls, so giant SD card waveform libraries and so on are out.

The code is open source, available on github.

The output sample rate is ~66.666 hz, there are up to 12 simultaneously calculated oscillators (depending on FX mode etc).

the output is 12 bit, and the waves are 512 point 16 bit. there is an analog fixed 19khz 4 pole filter to keep any digital HF from getting in your modules.

The 1v/octave input is real time converted, no look up tables or silly pitch bend schemes. the resolution is 1/72 of a semitone.

The idea is to have 3 waveforms which are interpolated between with the central knob and the "position" CV input. this way you can get a lot of variation with only one CV.

There are selectable waveforms on low, medium and high, the available waves change depending on what mode it is in (saw and square are not usually good for FM for instance so there are not many available)

at the most basic you can interpolate between them by turning the knob and fade perfectly smoothly between the different waves.
waves are selected to never cancel out and leave dead spots, as well as for their sound. (but not finalized yet) you could put in your own waves if you had the inclination.

the detuning is modulate-able, not only the frequency (which in normal mode can be an octave) but the amount via the detune enable buttons and the position. dynamic detuning is not something i have seen used much in synths, it is quite powerful.

In normal mode the detuned oscillators are evenly spaced above and below the main frequency, In prime mode, they are separated by prime numbers. this makes an overlap or "beat" of all the oscillators being in phase very unlikely to happen (i have not seen or heard it once yet) some other behaviour changes as well. in normal mode the range is much wider and you can do "hoover" octave up and down sounds.

I have called the modulation controls FREQ and INDEX, even though when not in FM mode that is not strictly true, but they do more or less the same thing. frequency and depth of modulation.

position, detune, index, and mod frequency all have analog attenuverter inputs, as well as the respective knobs

Either an on-board 12V -> 5V regulator can be used, or the module can draw from the system 5V rail. Power draw is also influenced by op-amp choice. With system 5V used, LME49740 U3 OPA2277 U4 it is 37mA on -12V, 39mA on +12V.

Muffs discussion (update after the january 2015 muffs threadopalypse)
original fixed now!

  • 39 mA +12V
  • 37 mA -12V
  • 50 mA 5V
  • 30 mm Depth
  • Ø 5.00 (3 Votes) Average Rating

Available as an assembled module and as a DIY project.