Midification of Conn 642 PART 1

[DaveKennett]

Dave’s Miditzer 216 PART 1

When I first downloaded the 216, I was so taken that I knew I had to have a console for it.  We had a 1960s vintage Conn 642 two manual with 25 pedals, but I was somewhat tired of the sound.  Could that be the midi source for the Miditzer?  Could I keep the Conn operable and still do the midi interface?  After a couple weeks surfing the net, I decided to proceed.  It then took about two months to complete after ordering the first supplies.  But there were some bumps in the road.  Special thanks to all those on the forums for smoothing out the bumps.  I hope that by telling my story, I can make the path easier for others.

Some internet research led to several hardware options that seemed feasible.  I decided to order  two CORE modules and six digital input (DIN) modules, along with some rainbow ribbon cable and connectors from SmashTV (http://www.avishowtech.com).  They were shipped on July 25th.  SmashTV was quick and accurate, but here’s what I did wrong.

2 CORE module kits w/PIC18F452, one Sysex ID 00, and one Sysex ID 01

No problem here!

6 DIN module kits

I was planning to use the keying voltage from the Conn to apply a + voltage to the DIN board when a key was pressed.  The board is wired with pullUP resistors, so that a key grounds the input when pressed.  I had to modify the board for pullDOWN resistors. The schematic for this board at http://www.ucapps.de showed that a jumper could configure it either way, but that is not the case with the SmashTV boards.  On the plus side, they use Dual In Line headers which mate nicely with easy to use crimp type IDC connectors.  If anyone is interested. I could post the details for the modifications separately.

3 1/4" Potentiometers

Used one for single expression pedal, broke one, and have a spare.

4 PCB mount MIDI jack

Didn’t need them; they are included in the CORE kits.

4 2 pin SIL connector

Used two for power hookup between COREs.

3 5 pin SIL connector

Did not use.

2 IDC connector 16 pin

Used one for connection of CORE to display (for troubleshooting)

1 (meter)16 conductor ribbon cable

Used about a foot for display (soldered to display)

35 IDC connectors 10 pin

Trashed a couple -  ran out - had to order more. Order at least six more than needed.

6 (meter)10 conductor ribbon cable

      WAAAY less than needed.  I ended up using about 80 FEET.

I also ordered a 00DM2004A-B-B6NTW 4-line display from 411 Technology Systems in San Marcos, CA.(Used only for initial programming and troubleshooting)  It served its purpose, and now sits in the box of leftovers from my project.

That should be about enough for now.  Next, I’ll talk about construction and programming the CORE modules.

Dave