Depends on how you approach 'trivial'. I've been hacking on Music Thing Modular Chord Organs for some time: they are a little Eurorack oscillator that can play chords, based on a Teensy. The Teensy audio library determines what waves you can get, and there's a 12 bit DAC built in.
You can specify the sampling rate of the Teensy with a bit of fiddling, and the limits depend on what you're asking the audio library to do. The stock Chord Organ's set up to run at 44.1k, using a couple of submixes in the library to do things like set waveform levels independently.
You can also set an oscillator to drive the output pin directly, with just one waveform.
I've got a couple of 'em running at 2,822,400hz instead of 44,100hz. That's 2,822k for one oscillator (I can get four running at 768k), by telling the Teensy its sample rate is something hilariously high, just to run some square and 12-bit triangle and sawtooth waves.
I avoid aliasing pretty well :) and it's definitely a fully digital DAC output. It's just good at being free from aliasing because I'm not concerned about what the sampling rate 'means' in terms of 'usable notes'. The only thing I care about is getting my waves nicer. The Teensy also has a rectangular wave, which is PWM adjustable. That, at 2,822k or even 768k, is quite nice even when it's a really thin pulse…
And of course you could use the square to drive an integrator :)
None of this was possible in the early 80s when the Junos were designed.
The Cortex M4 in the Teensy runs at 200MHz. In the early 80s consumer-grade DSP didn't exist at all. There were some exotic studio processors with slow microprocessors supported by custom hardware multipliers, but 8MHz 16-bit microprocessors were considered fast, expensive, and exotic.
Roland had a stellar run with their hardware designs. The Junos may be one of the best synthesizers ever made hitting the bullseye for price, character, simple but flexible programmability, and a legendary sweet but powerful sound.
There's a finesse to this kind of audio design that IMO makes a lot of Eurorack seem clumsy and uninspired in comparison.
Agreed.
Its also pretty amazing what Yamaha was able to accomplish in the 1980s with the DX7 and successors using entirely digital synthesis without capable DSPs or microcontrollers.
Some interesting background here: https://www.gearslutz.com/board/showpost.php?p=10602091&post...
The thing with eurorack that can feel uninspiring because it's never one music instrument, especially if you rewire it often and it becomes this abstract blob of music tech that is never finished, which makes it both addictive and expensive.
Also, Teensy is amazing! I got one recently to play with some audio stuff and it’s so much fun. Amazingly capable board really, love that it can do USB MIDI etc.
You can specify the sampling rate of the Teensy with a bit of fiddling, and the limits depend on what you're asking the audio library to do. The stock Chord Organ's set up to run at 44.1k, using a couple of submixes in the library to do things like set waveform levels independently.
You can also set an oscillator to drive the output pin directly, with just one waveform.
I've got a couple of 'em running at 2,822,400hz instead of 44,100hz. That's 2,822k for one oscillator (I can get four running at 768k), by telling the Teensy its sample rate is something hilariously high, just to run some square and 12-bit triangle and sawtooth waves.
I avoid aliasing pretty well :) and it's definitely a fully digital DAC output. It's just good at being free from aliasing because I'm not concerned about what the sampling rate 'means' in terms of 'usable notes'. The only thing I care about is getting my waves nicer. The Teensy also has a rectangular wave, which is PWM adjustable. That, at 2,822k or even 768k, is quite nice even when it's a really thin pulse…
And of course you could use the square to drive an integrator :)