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Subject: Re: [korgpolyex] Re: The latest news on HAWK

From: Michael Hawkins <korgpolyex800@...>
Date: 2016-05-27

I would include the NJM2069 so that the entire originality of the Poly-800 would also be retained.

I don't mind using some pre-mapped tables in a sampler mode. But I would also prefer discreet oscillator wave forms that can be modulated, PWM'd etc. Just how much can be done will depend upon the CPU performance capacity. And coding skills and techniques.

To begin with, the most important goals are to simply replace the 80C85 CPU and MSM5232 with the STM32 and recreated all of the Poly functions. This in itself doesn't sound like much etc when you consider just how much more can be done with additional CPU performance and storage capacity. For a start, the envelope generators and all performance controls (except the keyboard itself) will be 16 or even 32 bit instead of 8. The DEGs will be able to be made much faster. And we can create many more modulation routings than are currently possible where the only restriction on doing more of them has been the CPU. Just making the existing TG with its locked clock into 8 fully independent oscillators will be a huge improvement too. The richness of tone where the detuning is fully independent should help alot. And, initially we can make the TG into an 8 stage instead of four stage harmonic block. That should also improve the character of the basic TG before we even consider using any wave samples.

I don't think the keyboard is something that bothers me that much because it's just too easy to grab a controller or other MIDI source to get velocity. But it might be nice to include a variable peddle input. Do people even use such a thing anymore? The challenge is to create a board that can be dropped into Poly or can be used to convert over to a 1RU unit. MK2 owners might end up being left out for now.

The Mk1/EX chorus board is definitely going away. The cables in and out of that board will just have to be integrated onto the new board.

I also want to include stereo panning effects as well.

Should be fun!

/Mike

From: "bperkins211@... [korgpolyex]" <korgpolyex@yahoogroups.com>
To: korgpolyex@yahoogroups.com
Sent: Thursday, May 26, 2016 7:14 PM
Subject: [korgpolyex] Re: The latest news on HAWK

 
Sounds like a cool project!

Seems it would take over so much of the Korg that it may just be best to make it's own module and transplant a NJM2069 into it.  And if you already are simulating VCF's on the STM, then would just one NJM be used at the final output as an extra filter to add in the mix?
Just seems the old non velocity keys on a Poly800 would be dead weight, as would the old chorus/amp board if you design FX in the code or use another uC for...  not much meat left on the bone when the new uC takes over.

Still it would be a cool project, I would love to help with the coding if I could..  To get the waveforms I suppose you would use premapped tables to reference, then convert to PWM output with a filter.

Tom the Electric Druid tried to explain how it all works with his little PIC vco chip.  His code would be something to look at to see how the tables work and how to "morph" waveforms from one to the next.

I am very green with C++/Arduino coding, but did have alot of fun making an arduino VC LFO for my NJM2069 external module project.
Help coding a project like this would be a nice challenge to sharpen coding skills.

/Blaine