casio pk-1

[jamiewoody]

i picked one of these up cheap, but i cannot find any info on it.

the sounds are pretty much EXACTLY like the sa series, however, i have no idea if  the board is the same.

the box at least is cool. the lid is white slightly bigger than the bottom, therefore, lots of extra plastic on top. the perfect place for controls, so as not to compromise the speaker!

there are red and blue graphics on the white plastic box. kind of unusual, i think. i assume it is early 80s, perhaps before the sk and sa series, but that is speculation.

so, the question of the day...are there any cool obvious bends for this?

[Circuitbenders]

you must have had a go at enough stuff by now so i probably shouldn't have to say this again but, just get in there and see what you can do with it. 

If you picked it up cheap then you've got nothingto lose.

[jamiewoody]

well, i am a total novice at this sort of thing. i mean, i am still learning some of the most basic and practical things of electronics. frustrating trial and error...i would like to learn from other's experiences, go for the obvious, then poke around and discover more.

i think there is something to be said for following in footsteps of others who have been there first.

[adamduke]

finished this a few days ago...just about the exact same as the other casio SA series except that the OKI chip is M6387-03 (haven't seen it listed as a variable yet) while pins 3 & 11 connected seem to be the trigger for hidden sounds, just like pins 11 & 15 on the other OKI chips.

most other mods for this series seem to work though!

[Circuitbenders]

I don't think i've ever even seen a PK-1 before. It seems like one of those odd keyboards that don't appear to actually fit into a gap in Casio's range that isn't already covered by something else, most of the SA series for a start.

Is it something else thats sold under the name PK1 in certain places in the world?

[jamiewoody]

this is the same keyboard as i have, adam...i think i messed mine up though. it will no longer power up.

any photos from the inside?

[jamiewoody]

if i get mine working again, i am going to put an oscillator on it! that is the coolest mod there is! i've done it to two keyboards so far! definitely the most "synthlike"!

[adamduke]

I do have some pictures of the inside, but I can't seem to find my camera that they're on...

All the mods are fairly straightforward things that have been discussed already for the Casio series...no re-inventing the wheel over here on this one...

I really must order some LTC1799's!  I tried the crystal switch mod on an SA-20 and not only is it annoying to have to shut the thing off and on every time you want to use the lower octave, but I think I mucked up my board while working on it, so now it scares me.  Also, the voltage starve and glitch mods are fun, but now that I have them on one keyboard, I wasn't really in a rush to put them on this one with the limited real estate and all...

jamiewoody: are you talking about a 555 oscillator?  I'd have to build a breakout box, I'd think...you and I both know that this puppy is only about 12" wide.

I've got a spot waiting for one of those on my SA-20, for sure!

====

BY THE WAY....I just wanted to mention that I've lurked on here for a while and I TRULY appreciate all the openness, general goodwill towards each other and the intelligent dialogue for people of all skill levels on here.  What a great way to get more people involved in this fascinating world.  You guys are all awesome in my books.


....back to learning and the four Rubbermaid bins of projects in my shop!

Adam.

[Ciderfeks]

I've lurked on here for a while and I TRULY appreciate all the openness, general goodwill towards each other and the intelligent dialogue for people of all skill levels on here.  What a great way to get more people involved in this fascinating world.

Totally agree Adam, well put.

[jamiewoody]

adam, for my sk1 i built a 555 oscillator.

for my sa-2, i used an APC, but the way it is wired up, it basically does the same thing in application as the 555 lfo. i'm pretty psyched, as i made  a wood cabinet for the sa-2 and did a jackson pollock style paintjob on it with 3 colours on a white cabinet!  pics to come! it is a lot of paint, so i am giving it a couple of days to dry. i am going to clear coat lacquer over it all next.

[jamiewoody]

i got this thing working again. not sure what went wrong, really. i hooked up an power supply jack, and plugged it in. it still did not work, so i started poking around with a rubber handle screw driver.

eventually i touched 2 pins together on the  bigger IC . it worked, then stopped when i took the screwdriver away. so, i soldered a jumper to these pins and it now works...i still don't know exactly what i did, but at least it works.

i am going to build an lfo for it, and i may do a power crash. i think i noticed the 5ths switch when i was poking around, so i may add that.

are these things basically the same as the sa-2? it seems as though it sounds slightly different, tone wise, but i cannot be for certain. i do like how there is a lot of extra plastic to mount lots of controls.

[jamiewoody]

on the looks of the cabinet, a side view would be cool.  these have a classic 80s "synth" look. a sort of angle.tappered look. the top, where all the print is, is the perfect negative space to mount pots and switches!

on room for an lfo, i think i may, since i like the original box look, remove the speaker and use that space for the lfo circuit.

i have heard it is best to remove speakers for a better power crash? what do i do with all these speakers then? lol

[adamduke]

BUILD DIY SPRING REVERBS FOR EVERYONE!

[jamiewoody]

adam, if i build DIY reverb for everyone, it is hardly di-Y!

more like d-WHY?! lol

[adamduke]

ok, so i went a little overboard by totally referencing the title of the post by phantompowers....