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syntherjack

Joined: Oct 29, 2012 Posts: 21 Location: Poland, Poznan
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Posted: Tue Oct 30, 2012 1:42 am Post subject:
OneDog - Pocket synth with sequencer Subject description: My new project of "all-in-one" hand-held synthesizer |
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Hello,
been reading this forum since few years, now its time to go more active.
I would like to present my new design - hand-held sequencer/synthesizer.
Sound engine contains 3 square wave generators and 4 triangle/square wave LFOs. 3 LFOs modulate pulse width of 3 DCOs, while fourth LFO act as output volume modulator - its frequency goes to audio range. You can create 2 8-step sequences simultanously: sound pitch (note) sequence and note slide sequence. The interface is extremely reduced (only 2 knobs, 2 pushbuttons and 2 switches), but creating new sequences is quite easy. Device has also 8 memory slots, each holds 8 step note and slide sequence. Circuit uses no DAC, all waveforms are mixed analogue. All fits in mint can and is powered with 9V battery.
Topology:
- 3 DCOs, analog output & mixing,
- 3 triangle wave LFO, modulating DCOs pulse width, synchronized with sequence,
- 1 square wave "effect" LFO,
- 8-step sequencer with note/slide sequence,
- 8 memory slots.
Controls:
- note selection (over 6 octaves),
- slide on/off,
- sequence transpose,
- sequencer speed,
- "effect" LFO speed,
- memory bank selection / read / write,
- "live" effects - double speed, reset sequence (not implemented yet).
Inputs:
- sync input (not implemented yet).
Output:
- line out.
Demo was recoreded in one take. No external effects, pure OneDog audio output. At 1:11 "effect" LFO comes into play. Hope You enjoy it.
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andrewF

Joined: Dec 29, 2006 Posts: 1176 Location: australia
Audio files: 4
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Posted: Tue Oct 30, 2012 3:36 pm Post subject:
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very impressive!
Are you planning to share/sell/manufacture these? |
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syntherjack

Joined: Oct 29, 2012 Posts: 21 Location: Poland, Poznan
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Posted: Thu Nov 01, 2012 9:51 am Post subject:
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The are some plans, but rather "foggy". Maybe i will launch it as kit, it's extremely easy to build and fits almost everywhere.
Jack |
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bbriadn
Joined: Sep 16, 2013 Posts: 1 Location: Canada
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Posted: Mon Sep 16, 2013 6:08 am Post subject:
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Fantastic! Have you decided how you are going to proceed with this? Kit, instructible, etc  |
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syntherjack

Joined: Oct 29, 2012 Posts: 21 Location: Poland, Poznan
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Posted: Mon Sep 23, 2013 4:24 pm Post subject:
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Hallo,
i'm in the middle of circuit / software redesign. I've added simple drum machine and improved synth engine (chords, oscillator sync, manual PWM and more). It sounds much better now and is quite power efficient. I will make some demo, after i finish. |
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capicoso
Joined: Nov 19, 2012 Posts: 128 Location: Argentina
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Posted: Mon Sep 23, 2013 5:20 pm Post subject:
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Nice. A video would be cool so we can see how you operate it.
What microcontroller are you using? |
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syntherjack

Joined: Oct 29, 2012 Posts: 21 Location: Poland, Poznan
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Posted: Tue Sep 24, 2013 7:30 am Post subject:
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It's based on ATMega8A microcontroller, clocked by internal oscillator @ 8MHz with 3,3V power supply. On 9V battery it works forever.
Here is video of operation:
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