Adjusting Casio Keyboard Electronics to 432 Hz tuning

[Lurch]

Hello All,

 

At this point, I am attempting to change the tuning on my older Casio WK-3200 from 440 To 432 Hz. I am aware of the Master Tune Function and I set it to -32 cents. However, 432 Hz is actually 31.767 cents. I would like for it to be exact and the Tune Function doesn't have that capability.

 

Is it possible to get inside of the keyboard and adjust the circuitry to change the setting?

 

Also, with the -32 cents setting in place and saving a song in Song Memory to the Midi (SMF) format, the midi format does not keep the -32 cent tuning. Is there a way to remedy that?

[CYBERYOGI =CO=Windler]

I have no experience with this model, but AFAIK all fully digital casios (generation MT-540 and later) are crystal clocked and thus have no tuning trimmer anymore. It might be possible to replace the quartz with an adjustable oscillator, but this may mess up USB or midi communication due to wrong frequency.

 

The limited resolution of tuning or pitchbend controls in digital keyboards have to do with the size of frequency lookup tables in rom to translate each note. Thus to save rom space (which was expensive), many cheap keyboards had only transpose in semitone steps instead of tuning, and pitchbend did rather a glissando than portamento.

[Casiokid]

There's a guy on Facebook and YouTube (DJ Steve Francis) who has three Casio keyboards including a WK3200, and  plays, records tracks with Audacity and sells his CDs all recorded at 432Hz -Check him out

Edited March 15, 2023 by Casiokid
better english

[Jokeyman123]

It can be done with an audio editor after the recording is done. I am looking at Audacity right now-select "all" go to "effect" drop-down menu-open "change pitch" and a select screen opens which allows for altering the entire track by semi-tones or by fine increments of frequency-and allows for stretch tuning also. This does not change the speed of the track (tempo), only the actual overal pitches/tuning-can be done for an individual wav file, or an entire composition as a .wav, .mp3 or any other audio file Audacity can open.

 

Of course this does not solve the problem of changing pitch in fine increments with the Casio keyboard which is what Lurch wants to do. At least one can make a recording and change pitch. I think some DAW's can do this but audacity is pretty simple to use for a one-pass audio recording.

[Lurch]

Yeah, The Audacity process works really great and fast. Very Handy, But yes, I just wanted to have live play be at exactly 432 hz including the smf player. The SMF play can be changed to -32, but only by going into the mixer After the song starts.  So, I have to allow enough blank space in the recording midi file before the song starts. Doesn't look like this will be an easy fix.

 

If there was a way to get into the midi properties to change the frequency, I could at least fix the midi files permanently.

 

Edited March 15, 2023 by Lurch

[Jokeyman123]

Could end up being a pretty tricky mod...but the 3200 has a pitch bend wheel.....I have never done this but throwing it out there.

 

Since the pitch wheel is a potentiometer-I wonder if you could change the pitch finely enough by adding a specific amount of resistance to the pitch wheel circuit, or even installing a separate pot to vary the pitch, at least for one tone at a time, not globally. I haven't done the calculation necessary to see if this is possible in such a fine increment-just a screwball idea i suppose. And then this will not affect a midi file playback, I'm pretty sure the pitch wheel is not active for a midi file, could be wrong, I don't know the 3200. And for this fine an increment-a fraction a cent, the 3200 as Cyberyogi suggests, might not be capable of such a fine incremental alteration regardless of how you alter the pitch circuitry.

 

Ironic-in that the early days of analog synths, where tunings could be continually adjusted-oscillators were famous for being unstable-one never knew when your entire instrument might shift up or down on its own. Now one ends up with the opposite problem. crystal-locked frequencies that sometimes also clock the CPU depending on design-so cannot be altered without changing the clock frequency of that CPU and screwing up the entire keyboard. Progress I guess....

[Chas]

@Jokeyman123- I did a quick online search for the W3200 release date, and it came back as 2012. If that's correct, then there's a strong likelihood that the WK is using digital encoders rather than potentiometers for its pitch bend wheel. With modern keyboards and synths transmitting and receiving all commands/ controls/ parameters digitally, many now use direct digital encoders rather than analogue potentiometers that have to go through analogue to digital conversion to be read.

 

But I am not 100% sure about this in the case of the WK,  so if anyone can confirm for sure please do!

[Brad Saucier]

Just a quick tip, WK-3200 was released in 2005. Pacparts website is a good reference for confirming the release date of a model.  They will have it listed on the main page of each model.  It's also a good reference for parts.