bending report: Casio PT-30

[computer at sea]

I got one of these lovely units on eBay for next to nothing, as it was listed in need of repair.  Turns out it needed a complicated procedure involving opening up the battery compartment and filling it with double A's.

Feeling ahead of the game, I spent an afternoon poking around the circuit board. 

Folks, this is one you can safely skip. 

The board itself is in two layers, the most accessable of which just has caps, some resistors, a handful of jumpers, and one not so useful chip.  The second board, where, I would assume, the main chip (which looks to be surface mount) is located, is firmly fastened down to the keyboard mechanism, and looking down at it you see not only the usual tops of screws, but also the bottoms of some other screws.   I took all of the screws I could get to off, but was perplexed by those upside down ones, and thusly couldn't get at the second board. 

Focusing on the top board I found about a dozen points that minimally affect the chord and rhythm section, either increasing or decreasing snare resonance, or muting chords or bass.  I thought about hooking these up to a rotary switch, as all the bends share a common point, but there is no room inside the case for any extra hardware.

Unbent, this is a lovely keyboard.  The memory function is more evolved than Casio usually builds, and the analogue percussion sounds are very very nice. 

[sk-1]

I have two of these and they are very nice indeed.  One of them is my very first keyboard, given to me as a kid for my birthday when they were just released in stores and has unfortunately yellowed slightly with age.  Too much sun, I think has given it a mild tan.  I've partly restored the casing back to white and the keys I have fully restored to white.  The other PT-30 I just bought on eBay last month for forty bucks and it looks brand new and white as snow!.  Apparently it has only been taken out of it's original box twice since 1984... so you could understand that it is immaculate and there is not a single scratch on the rear panel.  It's cardboard box has undamaged corners and there are no marks, scrapes, scuffs or scratches anywhere.  Even the foam and manual look brand new so you can tell I am DEFINITELY not bending it or hacking into it!

BUT...

... my slightly yellowed and partly restored PT-30 is going to get (hopefully) a MIDI upgrade from Highly Liquid and also perhaps a DB-25 output for a circuit bending breakout box.  I hear the analog drums on the PT-30 are quite nice to bend and if done properly, you can get some pretty fat and wicked sounds out of it.  And poke around a little more because that bottom board is easy to lift and there is one or two screws hidden behind the protective foam that you see crumbling off the speaker wires.  Look at the main board edge and look under any foam that is stuck to it.  And watch out for the little board that sits behind the Casio logo (the tiny one connected by a ribbon cable).  That tiny board is GLUED to the front casing and you will need to carefully lever it off with a screwdriver.  I used a few layers of double-sided cellotape to secure it back on later.  And you won't have to undo any of those 'upside-down' screws to get at the keys because it sounds like you haven't found all of the screws that hold it down. I also missed a couple of screws because they were hard to find.  But eventually I unscrewed every single one of them and found that I never had to unscrew any reversed screws at all.

Anyway, if you ever manage to get the main board lifted up, WATCH OUT for the LCD display as it will come out loose and flop around quite possibly damaging the cable it hangs from.  That LCD is VERY fiddly and I had trouble keeping it dust-free and getting it to sit back in properly.

The PT-30 is a tricky board to pull apart, but I managed to get it down to 5 main pieces for cleaning and repair.

Most of my keyboards are immaculate so I ALWAYS go the breakout-box route.  It's so much more discreet.

But yeah... bend it only because of it's nice, warm analog drums.  From what I've read, there isn't much else to find under the hood of a PT-30.