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Subject: Custom MIDI controlled NJM2069 Project

From: bperkins211@...
Date: 2014-09-13


Hello all,



I could use advice/help in recreating a NJM2069 VCF/VCA circuit.


I am going to use the DW8000 service manual as a reference, since I have one of the "voice" boards from that synth to use parts from..
I might as well re use the caps from one voice to simplify things.. there's an op amp in there too..
I already have all the filter chips removed.. might as well recycle the OEM caps and anything else I might manage to desolder with useable leads.



Here's a link to a nicely scanned DW8000 Service Manual


http://manuals.fdiskc.com/flat/Korg%20DW-8000%20Service%20Manual.pdf




I'd like to know what would be a good, cheap way to get a dual/bipolar supply

Any ideas better than this?

Dual 5V Power Supply Mini Board
looks like it would be about $10 + $4shipping for one of those.






I am going to attempt to make an interface that will control a NJM2069 with a MIDI interface system..
This one..  (I have a few of them on hand, even though they were sold out/discontinued)

MPA: MIDI Decoder with 4 Digital Potentiometer Outputs and 8 Logic Out – Highly Liquid Store


This custom controller will have a standard MIDI jack to send it MIDI msg's.
The controller will have a 4x digital potentiometer 10KOhm.
It will also have a few ports for G/+5v to toggle so I can possibly trigger/gate a  SSM 2056 ADSR I have on hand as well.



The point is to use an assigned MIDI CC msg to open/close the VCF cutoff, Resonance and perhaps both VCA's
I can also assign it to respond to any MIDI Note ON/OFF msg. to trigger once or retrigger the trig./gate for the ADSR.

I was also thinking of placing pots on the exterior of the case to control mainly the ADSR setup so it is purely analog.
Maybe a way to add a couple pots to also over ride the MIDI controls and have pure analog control of the filter CO and resonance.

Then I can create a custom VST controller (the easy part) so I can map all the controls to hand drawn waveforms and such inside a DAW.

Basically it should be able to not only control a raw input's Filtering/Resonance, but also the Volume so it can "beat sync" or Slice the input sound using the DAW's built in editing.

anyone interested in chiming in some help/advice?

~Blaine