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Subject: Re: [korgpolyex] Re: What would everybody think if...

From: Michael Hawkins <korgpolyex800@...>
Date: 2017-02-01

Thanks for taking the time to run through all that. I remember you pointing me at the teensy before. This time, I shall definitely have a long look at it.

On your say-so, I shall give the DSP-G1 a pass.

Thanks!

/Mike



From: "bperkins211@... [korgpolyex]" <korgpolyex@yahoogroups.com>
To: korgpolyex@yahoogroups.com
Sent: Wednesday, February 1, 2017 4:11 AM
Subject: Re: [korgpolyex] Re: What would everybody think if...

 
It was not but a month ago I was messing around with a DSP-G1 chip.  First I got it running on my workbench, then I brought it up to plug into my VST studio to add some reverb/delay.

I'd like to say first that I am not knocking a tiny synth packed into an 8 pin DIP package.  It's pretty impressive considering the memory limitations Jan had to deal with and the features he actually got into it.
But the more I played around with it, the more I wanted MORE from it.

Does it have a sawtooth voice?  Yes.  And it sounds more full with three DCO's and the detune adjusted.  But, the output of the chip seems kind of thin. 
Is it better sound than the Poly?  A little bit.  The saw sounds alot better and the detune effect is much wider.

The BIGGEST ISSUE IS ADSR's do not seem to be logarithmic.  They sound more linear tapered, as do the adjustments when controlled via MIDI CC (FIlter Cutoff control, for example).  Something about those ADSR's had me pretty frustrated...
There isnt any portamento.  Just a Range adjustment to glide the notes manually.


I do have the source code for that chip, it is available on hackster.  But it is only for personal use.. there is not a release for commercial use.

Is it possible to take the code, get a proper IDE setup and tweak things such as the MIDI serial port speed?  Yes.
I've gone thru the code and played with the idea to merge the chip with the HAWK before.
In the end though, I was pretty disappointed in the quality of the DSP chip.  It was fun to play with for about two hours, but then I realized it was not really meant for more than a simple synth.

What I have my eye on now it the Teensy Audio Adapter Board for use with the Teensy 3.0+  family of boards.
I figured on getting the Teensy 3.2 with the Audio board.

Here's links-
Audio Board  $15
PJRC Store


Teensy 3.2 USB board  $20
https://www.pjrc.com/store/teensy3_audio.html



Teensy Audio Library page (with tutorials) 
Teensy Audio Library, high quality sound processing in Arduino sketches on Teensy 3.1



This setup has much potential.  Easy to begin development.  Has a fairly powerful processor on the 3.2 board with 256k of program memory.
It has an expansion memory on the Audio board available for future Wavetable applications.
There is support to use TWO Audio Boards for Quad output.
The USB port can be configured into a MIDI interface.
Built in DAC/ADC's.  It can do both generated sound and process external input.
It has effects built in.
There is an active community and Paul, the designer, is very active in support.
It's Open Source.
It is setup to use the Arduino IDE to build code and compile.. a very popular format that is easy to use.


Those DSP chips seem to be very limited in comparison to the Teensy system.
Might want to check the Teensy out!

Here's a vid of a kid that made a simple synth out of one..
https://youtu.be/KbcNqarBTsI

and another example...
https://youtu.be/MxDHKpysxYs



/Blaine