Korg Poly800/EX800 Users

The board itself is OK for what it needs to do now. Which is to
dramatically improve envelopes, sequencer, LFO's, velocity, modulators
etc etc.
With that in place, I can add hardware (not to the CPU board) that will
be wired in to the main board. Much like the AtomaHawk but a much more
powerful board.
This could include a "voice board" that will be modular and allow
different options. Your results so far look fantastic, especially as a
foundation.
/Mike
On Wed, 2019-01-30 at 10:25 -0600, Synthetech bperkins211@...
[korgpolyex] wrote:
> Mike,  what F4 chip are you using?
> 
> A dual DAC I drive uses a I2S port.  It is driven via interrupt
> triggered DMA.
> The bit rate/clock is approx 1.4Mhz for 44.1Khz stereo sample rate.
> That DMA works great but it doesn't leave much time between
> interrupts to do other things.. especially if they are slow
> processes.
> 
> 
> Sounds like you ordered a lot of boards.. Kinda has you locked in for
> the design?
> 
> /Blaine
> 
> 
> 
> On Jan 30, 2019 8:44 AM, "support support@hawk800.com [korgpolyex]" <
> korgpolyex@yahoogroups.com> wrote:
> >  
> > Hi Blaine,
> > 
> > See the picture. This is the CPU replacement for the Poly-800. I
> > just ordered 100 pieces to begin testing the hardware and writing
> > new software.
> > The board is based on the STM32F4. Poly-800 owners will have to
> > remove the 80C85 CPU and pop this unit in.
> > 
> > With this installed, there is enormous potential to give the Poly
> > new voices. Much like you said below. We could place new voices
> > before, after or in parallel with the Korg filter.
> > 
> > Clearly, you have done a large amount of the work. And I don't
> > believe in reinventing the wheel. So I would hope that we could
> > come up with some way to integrate our activities in some way.
> > 
> > For one thing, I would like to see if it is feasible to drive a
> > dual D2A via my board. If that is possible, then I could probably
> > reuse most of your code.
> > 
> > 
> > 
> > On Tue, 2019-01-29 at 17:51 -0600, Synthetech bperkins211@...
> >  [korgpolyex] wrote:
> > >  
> > > Hi Mike,
> > > 
> > > I would be interested in collaborating with you.  Did you have
> > > anything in mind or any details?
> > > 
> > > I am still ironing things out with this.. but I believe in
> > > another month or so it will be working much more smoothly.
> > > It's slow going.  I only have some evenings and weekends to dive
> > > into the coding. I've been learning alot along the way.
> > > It's taken a long time just to study the code to understand it
> > > enough to dive in and modify it the way I want it to work.
> > > Every night I mess around with it, it gets a bit better :).
> > > Honestly I didnt think I'd ever get it working, but I just kept
> > > at it and very surprised at the results.
> > > 
> > > It could be possible to use a smaller chip, the F405RG instead of
> > > a 407.  Get pin size down to 64 instead of 100.
> > > 
> > > The possibilities can be very interesting.  This synth could be
> > > mixed in with the Poly's original DCO's and perhaps have a way to
> > > selectively run it through the Analog Filter chip.
> > > Of course the built in FX wont be much good if you used them
> > > while running it thru the Poly's VCF.
> > > It's also very possible to make a standalone version too.. Could
> > > be a side project that people would be interested in.. a cheaper
> > > Shruthi.
> > > 
> > > I just got in the $1.08 16/24bit stereo DACs from DigiKey.  I'll
> > > have to wait a few weeks for some breakout boards I bought on
> > > ChinaEbay to mount/test them.
> > > Unbelievably cheap how much this stuff is now.
> > > 
> > > I have a ton of ideas, very interested in hearing yours.
> > > 
> > > /Blaine
> > > 
> > > 
> > > On Mon, Jan 28, 2019 at 6:09 PM support support@...
> > > [korgpolyex] <korgpolyex@yahoogroups.com> wrote:
> > > >  
> > > > Hi Blaine,
> > > > 
> > > > it's great work! I am in the process of testing a new board for
> > > > the Poly-800 that is based on an STM32F4 too! The design
> > > > doesn't give the Poly any new DCO waveforms so I am very
> > > > interested in your work and how we could collaborate. I would
> > > > imagine it would be great to take what you have done and
> > > > develop it into a board to go into the Poly.
> > > > 
> > > > Let me know what you think about that.
> > > > 
> > > > /Mike
> > > > 
> > > > 
> > > > 
> > > > On Sun, 2019-01-27 at 20:57 -0600, Synthetech bperkins211@gmail
> > > > .com [korgpolyex] wrote:
> > > > >  
> > > > > Hey Mike,
> > > > > 
> > > > > I noticed it's been awful quiet on the yahoogroups.  Been
> > > > > busy?
> > > > > 
> > > > > I've been working on and off on this STM32F4 synth chip.
> > > > > It's been a slow progress, but I think I may have something
> > > > > almost usable here.
> > > > > 
> > > > > Here is a private/unlisted video..
> > > > > 
> > > > > https://youtu.be/Z6L2gvHk7sw
> > > > > 
> > > > > I'm keeping this quiet for now because I'm not sure if I want
> > > > > to share the work I've done so far with the public.
> > > > > 
> > > > > Anyway, take a look and let me know what you think.
> > > > > 
> > > > > /Blaine
>