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Circuitbenders Forum => Circuitbending discussion => Synths & Samplers => Topic started by: museumoftechno on November 26, 2007, 11:03:42 AM

Title: Octave control for Casiotone?
Post by: museumoftechno on November 26, 2007, 11:03:42 AM
Hello

I've got a couple of Casiotone keyboards, and I'd like to modify one (ideally my MT-52) specifically to lower its pitch by one octave.

Is there anyone who can make specific mods like this, or who knows how it can be done?

Cheers

Dave
Title: Re: Octave control for Casiotone?
Post by: Circuitbenders on November 26, 2007, 03:06:07 PM
Museum of techno eh? Welcome aboard sir!  ;)

Off the top of my head, and i could be wrong as i don't have one here, i think the MT52 has its clock speed controlled by a crystal oscillator which will probably look like the pic below .

(http://content.answers.com/main/content/wp/en/thumb/2/2c/200px-Crystal_oscillator_4MHz.jpg)

or a ceramic resonator 

(http://img-asia.electrocomponents.com/images/RF174081-01.jpg)

Either way, if you get a component of half the value of the existing one and arrange some switching so either the original or new component are used then i'm thinking the clock speed should half and the pitch should drop by an octave. Unless of course the relationship between clock speed and frequency is linear or something more complex or i'm talking complete rubbish here. I have been awake way to long.

Anyone?
Title: Re: Octave control for Casiotone?
Post by: Signal:Noise on December 01, 2007, 01:20:37 PM
I managed to find an octave drop mod for a casio tone mt55, i'll see if i can find pictures.
Title: Re: Octave control for Casiotone?
Post by: museumoftechno on December 15, 2007, 12:46:35 AM
Wow, thanks for the replies! I've not got any further with this... I'll have a look at the circuit board though, see what pops up.

This week I made a bass stylophone, although it's not a bend, I just hacked together a NE555 as an oscillator, a shitload of carefully selected resistors, some crappy capacitive filter circuit, and some aluminium sheet that I cut up with a pair of scissors. Which are now charlie chucked. It does, however, emit ALL the fucking bass.