Review: Kenton MIDI kit for Korg Trident (Mk. II)

Tony Clark clark at andrews.edu
Wed Nov 19 02:59:45 CET 1997


   Well I'm back from another round of soldering, drilling, and 
frustration!  This time I have installed the MIDI kit for the Korg 
Trident Mk. II...
   Let me put my disclaimer up...

WARNING WARNING WARNING WARNING WARNING WARNING WARNING WARNING

   This is a tough kit and should not be attempted by the
                       DIY novice!

WARNING WARNING WARNING WARNING WARNING WARNING WARNING WARNING

   Okay, well, it wasn't as tough as the PS-3100, I'll say that up 
front!  Amazingly it CAN be installed by studying the installation 
instructions that Kenton sends with it, but you'd best be paying 
attention!  I'd still recommend getting the schematics for it though 
(thanks Mark!).
   Again, as with the PS-3100, Korg does NOT have the schematics or 
manuals for this machine.  Very annoying.  See my PS-3100 kit review 
for wonderful tech. personnel comments on this matter.
   Okay, well here's the scoop on the MIDI kit installation:

   The first big step is to drill the holes on the backside of the synth 
for mounting the MIDI sockets and setup button.  I used a hole saw that 
fits onto my drill to do the MIDI sockets.  Other people might suggest a 
panel punch.  Certainly that would be a little cleaner because I had to 
be careful not to get metal shavings all over the inside of the synth!  
This was easily prevented by using paper towels.  With the top of the 
synth open, get the edges of a paper towel between the top panel hinge 
and the wood underneath.  Let the towel lay down on top of the voice 
boards.  Now all of the metal shavings will be caught by this.
   Due to the way the back panel is arranged, I had to be extremely 
careful where I drilled the holes.  There is a circuit board (for the 
cassette functions) that could have been damaged by careless placement.  
As it ended up, the MIDI sockets and setup button sit directly underneath 
this board with practically no space between!
   The next big step is to get the digital board installed.  This kit, 
as was the case with the PS-3100, has two boards (digital and analog).  
Both boards sit on a metal backplate which is mounted ABOVE the main 
processor and voice board.  In order to mount it thus, I had to install a 
wood block on the inside of the left wood sideboard.  Fortunately the 
side wood pieces are really thick (1 1/2" or so) and can accomodate a 
pretty long screw.
   I suggest drilling the holes in the wood block as shown in the 
installation instructions, but COUNTERSINK the holes for the screws that 
mount the block to the side wood piece.  This will allow the mounting 
screws to pull into the wood far enough to give (me) piece of mind.
   Unfortunately the digital board has to be removed from the metal 
backplate in order to mount the backplate onto the wood block.
   Next I had to attach two ribbon cables to existing cables that connect 
to the main processor board.  Note that the Trident actually has TWO 
processor boards.  One takes care of the various keyboard functions, 
while the other takes care of the synth section memory functions.  Wierd, 
eh?  But at least it isn't stressed out like some other synths we know!
   In order to attach the ribbon cables to the two existing ones, I had
to do a little bit of tedious work.  The existing cables have plastic 
housings on them that attach to headers on the processor board.  The best 
way to attach the digital board cables to these is to remove each of the 
female pin connectors in the headers one at a time and solder the correct 
digital board wire on top of the existing wire connection to the female 
pin connector.  Then stuff the two wires (now attached to the female pin 
connector) back into the header.  Did that make sense?
   After connecting the two cables to the main processor board, the next 
step is to solder the ground wire from the digital MIDI board to pin 20 
of the processor on the main processor board.  Really I don't see why 
this is necessary since the power connection to the digital board 
supplies the same ground.  But just in case...
   Now the metal backplate can be mounted onto the wood block.  Then the 
digital board can be mounted back onto the backplate (watch that ground 
lead).  The two cables that were fitted into the main processor board can 
be connected to the MIDI board.
   The power cable can be soldered in next.  The Mk. II has a different 
power supply board (I think) than the Mk. I, so be careful where this  
is attached.  On the Mk. II the main power supply board has three outs 
and this is where the cable should be attached.
   Now the power cable can be attached to the digital MIDI board.
   I then soldered the MIDI sockets and setup button to their cable and 
plugged that cable into the MIDI board.  At this point the unit can be 
powered up and tested (keyboard MIDI only).
   Next came the analog board.  First mount the analog board onto the 
metal backplate holding the digital board.  The analog board has a number 
of wires leading out from it and these get attached to various points on 
the top panel.  Some wires are cut from the jacks on the back panel and 
new connections made, but don't worry, it all works out.
   Once everything is connected, the installation is over!

   How does it work?

   Good.  Fortunately the Trident has a 61-key keyboard, so I was right 
at home on my master (DX-11) keyboard!  Since the PS-3100 has only 48 
keys, I'm left with some dead keys on the top and bottom of my master 
keyboard.
   The MIDI controls are pretty good.  For starters, there are two 
controllers that can be assigned to any MIDI controller that you want.  
Unfortunately you can only let them control the VCF.  Other fixed 
controllers such as the aftertouch and velocity can control the VCF 
(both), VCA (velocity), as well as modulation and pitch bend (aftertouch).
   The kit can also respond to various MIDI messages such as "all notes 
off" and  "reset controllers".
   MIDI setup is done by pressing the red setup button on the backside of 
the synth and then pressing keys on the _master_ keyboard corresponding 
to the various MIDI functions as shown on a chart that comes with the kit.  
Takes a bit getting used to but is fairly quick once accustomed.
   For those of you that read my PS-3100 kit review, its MIDI controls 
are pretty much the same.

   Well that wraps up this review.  No doubt some of you are probably 
wondering why I have bothered to write all this stuff about the kits.  
>From where I stand, the guys at Kenton and Encore and etc. are providing 
some invaluable services to the analog community by designing these 
retrofits.
   I know that I couldn't possibly HAVE my analog synths in my studio 
unless they are retrofitted. That's just the way I've got to have it!  
And so I want to share my knowledge of their MIDI products and the trials 
and tribulations that go with it, so that anyone who has ever 
contemplated buying one of these kits can have at least one reference 
from someone who's actually done it.
   Well enough from me...I guess I need to go buy me some more MIDI 
cables now...

   Tony

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