I am considering getting a Gakken SX150 ( http://www.makershed.com/ProductDetails.asp?ProductCode=MKGK8 ), and want to make it into a MIDI controller. However, I do not have much money and would not like to spend money on hardware mods. I came across this program ( http://cmpercussion.blogspot.com/2008/08/theremin-to-midi-control-program-in-pd.html ) for use with Theremins, when I was researching Theremins, and was wondering if it could be used with a Gakken SX150. Would I need to keep it on a clean tone? If I needed to modify this program, how extensively and how much knowledge of pd would I need? And finally, would it still work if I decided to add a ribbon controller to the Gakken, like this http://www.coagula.org/content/pages/gakken-sx-150-hacking-controller-tutorial ?

Hello, Tanderbolt:
It appears to me that the modification proposed on:
http://blog.makezine.com/archive/2008/07/how-to-control-a-gakken-s.html

cited by the site you posted:
http://www.makershed.com/ProductDetails.asp?ProductCode=MKGK8

talks about controlling the SX150 via midi. As far as I know, a midi controller at least sends midi data to other devices, in the best case both ways. It may work if you have a theremin wtih midi out, so you can make sounds out of SX150 just playing your theremin.
I'm not on hardware-pure data interaction yet, but maybe some model of arduino suits your needs. Good luck with circuit bending anyway!

Sumidero

PD: http://www.arduino.cc/cgi-bin/yabb2/YaBB.pl?num=1148420030
http://puredata.hurleur.com/sujet-5679-puredata-arduino-send-receive-object

I have seen that article, but there are a few concerns I have. Firstly, I am looking to use a Gakken as a controller, not have it be controlled. Secondly, I want to stay away from hardware mods because I am broke. Also, to clarify, I do not own a theremin. I was interested in one at one point, when I found the pd program I posted, which can convert the audio in signal of the Theremin into MIDI, no hardware modification needed. I was wondering if I could modify it to work with the Gakken.

From what I know the Gakken SX150 is a DIY synth kit... with no midi out. So what you need to do is convert the incoming sound/tone/signal from the Gakken into midi numbers/notes. There is an object in PD-extended called [fiddle~] that I think should be your starting point.

What you are attempting to do is definitely possible, but it's not going to be easy if you're jumping into pd for the first time. There are other on this forum more knowledgeable then I on how [fiddle~] or [env~] works, but in order to take advantage of the help and tips you receive, you will have to have a good grasp on how PD works, how to get around in the environment, and the basic objects.

You can check out help patches and examples under the "Help" -> "Browser" menu.
I would recommend to read the PD FLOSS manual here:
http://en.flossmanuals.net/pure-data/ - read, do the tutorials - not all the information there will be specific to your needs, but it's well worth the time to learn it.

gakken's ribbon controller is really cheap and nasty, have you ever tried one? they are the flimsiest piece of junk ever.

for a ribbon-type controller that you can easily use with your computer straight out of the box without any modification or anything, look at the KORG nanopad. It's got a chaos pad style XY grid controller (just use the x or y axis if you want it to be a ribbon), also has 8 pad buttons you can use for interesting things. It connects straight to your computer via USB, so no need for a midi interface, AND you can be assured that the build quality of Korg stuff is going to be much better than some cheap magazine kit like the gakken.

amazon says you can get a nanoPAD controller for $40, which is as cheap or cheaper than the gakken anyway.

I have to say that you don't know what you are talking about. He is trying to modify A SYNTHESIZER so he can put midi into it.

HE IS NOT LOOKING FOR A MIDI CONTROLLER. I think you may have understood his question wrong. AND BTW, I own a gakken sx-150 and I've made some amazing sounds with it for what I paid for it. Just saying.

Cheers

@Tanderbolt said:

Firstly, I am looking to use a Gakken as a controller, not have it be controlled.

Looks pretty clear to me.