Help me figure out my ring mod/joystick project.

[Taylor]

Er, please.

After seeing Colin's Nintendo Muff, I got this idea to do a stereo ring modulator where the x- and y-axes of a joystick would control the two carrier frequencies. I picked up one of these controllers and realized that it's not that sort of deal at all, but just 4 buttons for up, down, left, right. So I've scavenged a joystick pot from a newer game system controller, and I've been figuring out the logistics of attaching the nintendo joystick to my dual perpendicular pot (is there a better term for that?).

Anyway, that's the idea. I need help figuring out which ring mod circuit would be right for this project. The idea is that it should be able to accept 2 inputs, either to ring mod them both separately, or to modulate one with the other as a carrier (selectable with a switch), and the x-axis should control one carrier frequency and the y-axis the other. I'd also like a traditional carrier frequency pot for each, in series with the joystick to select the range in which the joystick will work (I have no idea what value and taper this thing is). I'm really not married to the stereo bit, but I would like to have 2 separate carriers, and a carrier input. If those 2 things can be done without having a real stereo setup that's fine with me.

Any ideas? Am I mad? Thanks.

[ExpAnonColin]

In order for something to be "ring modded", there needs to be two signals...  the audio and the carrier.   Are you asking for a circuit that has two inputs, each can either be modulated by seperate carrier waves or modulate one another?  If so, no such circuit exists to my knowledge, but it wouldn't be too hard to hack one up.  If you just want to have 2 inputs, one that modulates the other, that's pretty easy... Most synth ring mods have this.  Check the schematics archive on my site...  In relation to the last bit of your post, if you  want the joystick to just "mix" between two carrier waves you only need a single input, and you'd be wiring the joystick as an active mixer between the two carrier waves.

-Colni

[toneman]

is this your 1st project??
did U google for "ring modulator"??
There's the simple dual xfmr diode ring (modulator).
This & MayB a couple of buffer OAs in & out would B about the
simplist RM U could build.
Check out the schemo on the old PAIA RM, the 4710.
Think schemo is @ Anders' site in NE.
staymodulated
tone

[Taylor]

Are you asking for a circuit that has two inputs, each can either be modulated by seperate carrier waves or modulate one another?

That's what I had in mind. But as I said, I'm not married to that idea.

In relation to the last bit of your post, if you  want the joystick to just "mix" between two carrier waves you only need a single input, and you'd be wiring the joystick as an active mixer between the two carrier waves.

-Colni

I guess I didn't explain this too well. What I had envisioned was that the joystick would control the frequencies of the oscillators that are being used as carriers. In this case there would be 2 separate oscillators, left/right on the stick being lower/higher frequencies, respectively, of one oscillator, down/up being lower/higher of the other. So I could use the joystick while I'm playing to simultaneously control 2 carriers.

This is not my first project, though I am relatively new to DIY effects. I'm familiar with what a ring mod does and sounds like (I don't know if I came across as not knowing what I'm talking about, or if it's just that I have no posts, but I did research before posting this). Anyway, thanks for the responses. I guess I'm going to try the passive ring mod with buffer opamps that toneman is talking about. I know I've read some things about that on your site, Colin. Off to read.

[Tim Escobedo]

A quick and dirty "stereo" ring modulator, where X is one stereo channel, and Y is the other, could be a very easy hack, since bleed through isn't a issue (or rather, bleedthrough is desired). Something as simple as summing the two channels through diodes might suffice.

Using a analog joystick to control two different oscillators, one for each channel, is certainly doable. But in this case, you probably want a honest to goodness balanced modulator where bleedthrough isn't desired.  The devil with such things, however, is getting a real balanced modulator. Transformer/diode ring modulators are damn near impossible to get cancelling bleedthrough. Best bet may be hunting down some relatively hard to find balanced modulator chips and using trimmers to null bleedthrough. In the end, kind of a pain in the butt (X2 for stereo). Look to analog synth DIYers for info.

[Dan N]

This is the schematic for a chime/gong/whatever synth called a Synchime. There is a grainy Maplin article somewhere on the web. I put one of these in an old Tandy joystick and it is a pretty fun noise maker (and an awful poor ring mod). I added an aux in with a switching jack between R14 and the junction of R17, RV3, pin 1 IC3a.

http://experimentalistsanonymous.com/diy/Schematics/Synchime%20Synthesized%20Chime.gif

The joystick pots were 50K, so I put in 1M range pots.

Edit- Just looked close and there is another switching jack between R15 and the output stuff from IC3b. Both jacks work when I inject a signal from a generator. Can't say which is better.

[Paul Perry (Frostwave)]

In my commercial ring mod (the Blue Ringer) I have a voltage controlled local oscillator (based around a CA3080).
THat might look like doing it the hard way.. but the advantage for you wiht a joystick, is that it is pretty easy to arrange a jystick to act as a voltage generator (OK two generators!) and then, you can use it wihyt other voltage controlled stuff as well, eg filters.

But, if you want something cheap & simple, use the joystick pots in 7555 oscillators.

And if you aren't worried about anythng, just want to sound like Mars radio, take square wave output from the 7555 timers & run them to an XOR gate as a poor mans ringmod.
Hell you could make this for $10 plus the joystick, spray it pink & sell it on *BAY for $$$. Just be sure the oscillators go down to LFO range for max mayhem.