[sdiy] Roland Juno 106

[brianw]

On Feb 11, 2024, at 1:50 AM, Gordon wrote:
> On Sat, Feb 10, 2024 at 04:42:08PM -0800, brian wrote:
>> What's "the digital part"?
> 
>> There's no need to 'clone' the firmware, since that digital aspect doesn't really affect the sound.
> 
> Okay, so you're saying that the way the control ranges interact, the way the envelopes work over particular ranges, and the way the LFO works - and the way that is all mixed together to control the oscillators and envelopes - you're saying that this "doesn't really affect the sound"?
> 
> That's an interesting take on it.

Thanks for the details. If you forgive me my engineering focus on semantics, then what you're saying is that the digital envelopes and digital LFO, as well as the specifics of the frequency control for the DCO, is what needs to be recreated. i.e. It's not a 'clone' of the CPU, per se, or the entire firmware, but the audible aspects and characteristics of the signals generated by the CPU - the envelopes and frequency controls - that are critical.


>> I'm just curious what you're saying has yet to be reproduced with modern technology...
> 
> Nobody seems to really understand what the voice CPU is doing, so they try to "improve" it. This is nothing short of disastrous. If you compare the JU-06 to a real Juno 106 for example, it doesn't sound anything like the "real deal" because it just doesn't get the envelopes even close to correct.
> 
> That's leaving out all the "higher order effects" like the inherent wobblyness that the LFO has, the variation in the envelope times, and so on. There's a lot going on in that 2kB of code and 1.5kB of lookup tables.

This makes sense.

Thanks again,

Brian