Jeannie 8-voice polyphonic open source synthesizer with 24dB Ladder Filter and 12dB State Variable Multimode Filter

Jeannie is an 8-voice polyphonic open source synthesizer kit with digital sound synthesis and digital filters based on a fast ARM Cortex-M7 processor with 1MByte Ram. For sound generation, the user has a variety of classic and band-limited waveforms at his disposal. A pool of 15 waveform banks with 63 different waveforms each offer plenty of space for sound experiments. A waveshaper with different characteristics provides for gentle to vicious sounding distortions. To tame the waveforms, there is a digital 12dB multimode filter with fade function from low-pass to highpass and a band-pass function. In addition, there is a 24dB LP ladder filter. A 24Bit DSP effect module with adjustable parameters rounds off the sound synthesis. An integrated polyphonic 16-step sequencer provides for the playfulness of the small synthesizer. A total of 2048 sound patchesfrom 15 banks can be loaded and stored via an integrated SD card. A color 1.8 inch TFT display allows a clear menu structure and easy operation of the synthesizer. The parameters are entered via four rotary knobs below the display and an encoder for selecting the sound programmes and switching to the menu functions. In addition, there are six buttons for operating special synthesizer functions.

• 8-voice polyphonic DIY synthesizer
• ARM Cortex-M7 processor 816MHz with 1MByte Ram
• two digital oscillators per voice
• 15 waveform banks with a total of 945 waveforms
• 12 standard waveforms partly bandlimited
• noise generator (white and pink noise)
• oscillator modulation (XOR, XMOD, MOD, AND, PHA, FM)
• Waveshaper with different waveforms
• 2 LFOs for pitch and filter modulation with 6 different waveforms and fade in and fade out
• 2 PWM LFO from 0.04Hz – 25Hz
• Digital 12dB multimode filter with resonance and crossfade function (LP/HP/BP)
• Digital 24dB Ladder filter with resonace and FM
• 2 ADSR generators 0.3ms - 12s with positive and negative control
• 24Bit DSP effect module with 15 effects and adjustable parameters
• Polyphonic 16 step sequencer
• SD cards for loading and saving sound programs max. 2048
• Color 1.8 inch display with 160x128 pixel resolution
• Volume control
• Boost function for improved bass response
• Stereo audio output jack 6.3mm
• 4 potentiometers for parameter input
• Rotary encoder for menu control and sound selection
• 6 function keys
• External power supply 12V DC / 1000mA
• and power switch



Jeannie Technique

Github: GitHub - rolfdegen/Jeannie-Open-source-Synthesizer: Jeannie 8-voice polyphonic open source synthesizer

Panel PCB


MCU Teensy 4.1

32bit DAC PCM5102A

Fx PCB SPN1001-FV1


There is Trusted Builder. Please ask

Greetings from germany. Rolf

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Hello, some people here in the forum still know me from the Shruthi/Ambika time. When Emilie stopped distributing these wonderful DIY synthesizers, I continued to distribute them at that time - and still do.
But the technology also continues. That’s why we now have a new synthesizer in our programme which is based on Shruthi and Ambika.
I also have to thank T-Synth who gave us many suggestions in the beginning.
Jeannie is 8 voice polyphonic, has a ladder and a state variable filter, 2 LFOs, 2 ADSR, 800 waveforms, wave shaper with 11 waves, step sequencer and much more.
We have also implemented an FX chip. Now there is reverb, delay, chorus as well and in really good quality. I always missed the effects in Shruthi and Ambika.
The software is open source.
I hope it is a worthy successor for Shruthi and Ambika.



Hi there , here is a new Video on Youtube

Jeannie Synthesizer

This explains the build and i had add some Soundexamples .
And maybe we build this engine with analoge filter …

Jeannie and 400 Patches

Have fun listening. :star_struck:
Sound only comes from Jeannie. No external effects.

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Nice video from Andre :grinning:

Have fun listening. :star_struck:

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Current voice patch (polyhonic 8 voices)

Greetings from Germany. Rolf

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Jeannie modulation menu…

24 Modulation Slots

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Jeannie & DeepMind Klang Impressionen

I like the sounds from 16:00 min very much

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