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Thread: New project with Teensy 4.1, DAC ADC and Analogs electronic....

  1. #1
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    New project with Teensy 4.1, DAC ADC and Analogs electronic....

    Hello to all,

    I would like to take the liberty of this short message to present a project in which Teensy 4.1 plays an important role.

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    I really want to thank Paul for the incredible work that is being done. I'm already a fan of the Teensy 3.2, two of which equip my "star" instrument (The River, a big analog polyphonic...).
    I'm now starting a new project in which the Teensy 4.1 takes a big place. It manages both the logic of the board and the multiplexing of all the voltages needed to drive the analog modules, but also offers a digital generator, designed as a support, a complement to the analog part. The 4.1 is completed by a DAC 8552 , a DAC PCM5102a and ADC CS5343.
    What fire power! The 4.1 manages 2 digital sources and destinations, with "nodes" encapsulated in classes that allow me to multiply the instances and types of syntheses.

    In this example, I don't use analog VCOs, all the sources come from the Teensy via the PCM5102a at 88K.

    Samples of sound

    The whole thing then passes through several filters and analog envelopes, VCAs as well as digital envelopes and digital LFOs, always generated by the Teensy. The latter does not exceed 20% of usage despite all this... Inexhaustible the bugger !!!
    A little before the end, you'll hear a bug I haven't managed to fix yet, 2 or 3 seconds of constant flow, I'd find

    At the very end, I add a bit of analog VCO, the cohabitation of the two seems very satisfying to me.

    Just one word then, thanks Paul and the whole community who brought me a lot of information ! I have developed a module that could be of interest to the community and that I will make available to you a little later: a wavetable generator that you hear several times in the demo, compatible with files from WaveEdit (256 * 64 samples). I also adapted the Mixers to allow 8 or 16 inputs, which seems simpler than mutiplying the Mixers.

    Best regards

  2. #2
    fantastic work, baloran! looks amazing!

  3. #3
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    Quote Originally Posted by lucian_dusk View Post
    fantastic work, baloran! looks amazing!
    Thanks Lucian

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    Sounds amazing too - worth the headphones for this one, not laptop speakers! Nice work.

  5. #5
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    Hey Baloran, sounds very good - thanks for sharing this
    How did you approach the VCOs? Did you built them from scratch / designed them by yourself, or did you have some template for them?

    Does someone of you guys know some good books about analog electronics in audio devices? would love to build an analog synth by myself one day
    MarkV

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    Hey! I'm so glad to find this post. I've been researching on how to pull something very similar to this off for the last few days. Loosing a lot of sleep. I don't really know where to start but there are definitively questions haha.
    Primarily I think I have two big ones!

    Just to run though the outlines of what I'm thinking. Teensy would generate all oscillators and controll voltages, and the audio would then run though analog filtering basically. Inspired by UDOs super 6, I'm thinking stereo signal chain just like you have aswell.

    Most pressingly I've been pondering DAC (i think). To just get started fidgeting with programming oscillators I really want to get a great base for the signal chain without any bottlenecks early on. I really want to give my moog a run for its money. 88k sounds like a very good start. Is there anything specific you think I should go for in the hardware to keep a high ceiling? How come you went for that frequency and not, say, 96?
    Basically, please recomment your favourite DAC for this application and maybe what you use to filter PWM to CV?

    And while I'm going, have you tried real-time waveform generation? Basically running the oscillators as functions instead of fetch tables? I'm really interested in how this platform would handle that with a large quantity (200-400) of sines or a few more complex algorithms. I think it would open some possibilities and, primarily, make waveform design, and just programming in general, a very different story.
    I'm just not sure the hardware can handle it yet.

    Thanks for giving me some new hope for my project! Have a nice weekend.

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    Quote Originally Posted by MarkV View Post
    Does someone of you guys know some good books about analog electronics in audio devices? would love to build an analog synth by myself one day
    MarkV
    Analog audio equipment is a very wide field and a complete jungle when you dig in to the practicals i dont know what level of knowledge you have, and I'm affraid i dont have any books to suggest. But if you are into synthesizers specifically I would recommend starting on youtube with channels like 'look mum no computer' that go into building modular sinthesizers. I myself started out studying filter topologies since those hold a lot of character.
    But in a wider sence i guess one needs some basic sence of the building blocks, what most analog audio equipment have in common is ofcourse the transistor (or vacum tube or op amp). So if you yet havent unlocked the secrets of those little buggers thats a good starting point i guess

  8. #8
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    Thanks to everybody

    Quote Originally Posted by MarkV View Post
    How did you approach the VCOs? Did you built them from scratch / designed them by yourself, or did you have some template for them?
    In this project, I use ALPHA RPAR IC (AS3320, AS3350, AS3340, AS3310, AS2164, AS3363 etc...). Nice products and prices These components are well documented, the old equivalents are in many famous instruments. My personal work consists mainly in creating an original architecture and the contribution of digital solutions in an this analog chain.

    Boober, For several days, the architecture being stable, I've been running at 96K. The CPU supports perfectly, I might keep this speed. A little further up I indicate the components used in ADC and DAC. There are two DACs, one for audio PCM5102a, one for the generation of control voltages DAC 8552 (16 bits 2 channels).

  9. #9
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    A great answer. Thank you! I'll read up on what you just said and maybe i can finally go ahead with my order.

    Quick side note, Booberg is my actual family name but it looks like a juvenile nickname when I see it in text haha. Damnit.

  10. #10
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    Quote Originally Posted by Baloran View Post
    In this project, I use ALPHA RPAR IC (AS3320, AS3350, AS3340, AS3310, AS2164, AS3363 etc...). Nice products and prices These components are well documented, the old equivalents are in many famous instruments.
    And oh! Those chips are pretty much the reason i got in to this project in the first place actually. After finally giving up on designing with discrete components a whole new wold opened up. They seem just amazing. But i'm thinking of going for the SSI2144 filter over the analog solutions CEM style one. Jusy because i love the mono/poly
    I'll definitively keep my eyes and ears open for future updates with your kit. More samples when you are ready please

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