Here you can find modifications that others have applied to their PPG instruments and kindly allowed me to display here.
Wave 2 Rack
This rebuild (to call it a "modification" would be mildly unfair :-) was done by Diego Wasser from Switzerland. He has added a MIDI interface to his Wave 2 and put it into a 19" case. To do that in a reasonable space, he has completely redesigned the analog and the TAS board.
Looks extremely good in my opinion! Here's a view of the slightly cramped interior of the case:
Pictures (c) Diego Wasser 2002.
Wave 2.3 with velocity-sensitive keyboard
This modification was done by Gregor E. on his Wave 2.3. To accomplish this, he put the keyboard of a Fatar SL 610 plus into the Wave and routed the keyboard's MIDI output to the Wave's MIDI Input.
After the modification, there's no visible difference:
In the Wave, there have been quite some changes:
In Gregor's own words (translated by me, admittedly :-):
The picture shows how the modification has been done: the original keyboard is mounted with 4 screws on each side. I cut an 8mm plywood plate to a matching size and bolted it on with wood screws through the existing holes. The Fatar keyboard is mounted in its original case with 12 screws, so you have to drill 12 matching holes into the plywood, which is a bit delicate. The Fatar keyboard can then be mounted onto the plywood from below with its original screws.
The pots for the mod and pitch wheel are removed from the Fatar, too, and inserted in place of the original PPG pots. The PPG ones have a different range and can't be used with the Fatar! Swapping the pots looks more difficult on first sight than it really is.
The Fatar electronics can be seen in the above picture on the little PCB above the keyboard; it has been mounted to the plywood plate with distance rolls and wood screws. The power supply for the electronics is done with the original Fatar power supply (on the left side in the picture).
One of the two MIDI Outs on the Fatar PCB is connected to my Wave's MIDI Thru port; to allow that, I've cut two traces on the Wave's MIDI PCB to inhibit a data collision with data coming from the Wave's MIDI In port. In a way, my Wave now has two MIDI Outs, an "original" one and one from the Fatar keyboard instead of the original MIDI Thru.
In my case, I don't need a direct connection between the keyboard and the Wave's MIDI In, since I control the Wave with a sequencer program. If you want to really do it perfect, you could of course merge the MIDI data streams with two MIDI Mergers (Philip Rees, for example); this way, you'd have a Wave that acts just like the original in every respect. (HS: I think that the Wave passes incoming MIDI events to MIDI Out, so one MIDI Merger on MIDI In should do. Yet to be researched :-)
The whole modification took me about 4 hours; if you know how it works, you should be able to do it faster. (HS: I doubt that :-) Unfortunately, the keyboard can't be bought any more; I got mine in an auction for 180 Euro. It might well be that the successor, the Fatar SL 161 works just as well.
Pictures (c) Gregor E. 2002
Wave 2.3 Rack
This modification has been done by DI Helmut Fischbach (who built a lot of stuff for Kraftwerk) for Manfred Hermann und Jon Kaiser from Berlin. For that, the whole Wave was "sliced" and put into a rack case.