My Big Polysix Modification Adventure

Well, I'm finally starting in.  I'm doing it.  My Polysix better look out.  It begins.

New Fatar Keybed with Aftertouch is on the Left.  Stock Polysix Keybed is on the Right.

A while back, I added aftertouch to my Mono/Poly.  It was a real hack-job, both mechanically and electrically.  It was ugly, but it worked.  It worked well enough that it made the synth feel so much more expressive and exciting.  I want this functionality in my Polysix.  I want it bad.

The aftertouch in the Mono/Poly worked, but it wasn't perfect.  The main problem is that the response from key to key is uneven.  If I'm going to do aftertouch again, I want it better.  To make it better, I figure that I should not just kludge aftertouch onto the exist keybed (like I did for the Mono/Poly).  I'm thinking that I should maybe find a keybed with aftertouch built-in.  And, if I'm buying a new keybed, I want one that feels nice...maybe a little less klick-y and plastic-y than the stock Polysix kebed.

After a bunch of searching, the only people that I could find that would sell me a nice Fatar aftertouch-enabled keybed were some very helpful British guys over at keyparts.co.uk.  They're the only ones!  Not even Doepfer (or his US reps) could get me what I wanted.  Weird.  So, I went with the British guys...and they were super helpful, so I was glad to give them my business.  The specific keybed is linked below.  You'll note that the keybed, it also has velocity sensitivity.  So, maybe the old Polysix will get both aftertouch and velocity!

http://www.keyparts.co.uk/shop?page=shop.product_details&flypage=flypage.tpl&product_id=20&category_id=8

With them being in the UK and me being in the USA, shipping could have been horrible.  But, the guys at Keyparts when to extra lengths to get the smallest box possible (total volume dominates the cost of something this light weight), which saved a ton of money is shipping.  Thanks guys!

Well, I received the keybed and it looks and feels great.  The picture at the top of this post shows the new Fatar keyed on the left and the stock Polysix keybed on the right.  The thin gray strip protruding from the end of the Fatar keybed is the aftertouch sensor.

So, now the adventure begins.  I've got to figure out how to wire the new keybed into the Polysix and I've got to figure out how to inject the aftertouch signal.  The aftertouch portion should be pretty easy (again, I'll just mimic the bench and mod wheels).  The hard part is wiring in the keybed.  There are several ways that it could be done...some simple but limited, some complex but powerful.  I think that I'm going to go for powerful.  That's for future entries.  Wish me luck...'cause here we go!

Edit: Here's my next step on the Keybed...Cutting the Keybed Feet.
Edit: Here's my next step on the Electronics...Replacing the Key Assigner.