Ring Modulator Suggestion?

[james t]

Hi everyone,

I am fairly new to this DIY-stompbox thing, but have found it to be quite a cool hobby.  I appreciate the community that you all have developed to involve new people like me.

I have a friend who has heard about my *working* prototype (a tweak-o by Joe Davisson, for whom I thankful), and has asked me how difficult it would be to assemble a ring modulator.  I have a copy of Craig Anderton's Electronic Projects for Musicians, and I know that he has a ring modulator project.

Is the Anderton one my best bet, or are there other either (1) cooler sounding, (2) easier to find parts for, or (3) more reliable designs floating around that someone has had experience with?  

Thanks in advance,
james t

[petemoore]

And I liked mine. Great Green tone, never really got it to unity, but probably coushould have tried a little harder...I'm waiting for the results to come from the new Stutter efkt [GEOFEX], it purportedly produces Ring Mod efkt. [Ihaven't tried it]
 IMO Ring Mod is really cool effkt. but I haven't seen a 'plethora' of schematic choices, maybe someone will come up with a 'Doubleringer' or something...
 The Green Ringer liked best to be 'goosed up' with a fuzz ckt as i recall.
 'I like my octaves *FTM, Tycho, Bobtavia...but they're just too severe to use with the present lineup and songlist.
  I too need to work up another good Ring Mod because I thing I could sneak that in there without being so conspicuoctavious.
 there are a couple others, A Dalekator [link in a recent 4-5 days ago post] which looks pretty wild, and is named after a Sci Fi films robot character [similarity in sound..'/?']

[moosapotamus]

Simplest ring mod type circuit is probably Tim Escobedo's Thing Modulator.

Do a search here for more info on ring mods in general.
Frobnicator
Green Ringer
etc... and, so on...

The Anderton one is pretty good (a couple of audio clips on my web site). It uses an obsolete opamp, but there is a good replacement for it (5532, maybe? can't remember right now). It does have a slight bit of carrier bleedthrough, but most of the simpler ones do, too. I think it's definately worth building if you've never built a ring modulator. You can even get a kit from Paia. Oh... also, the Anderton ring mod needs a bipolar power supply, two 9V batteries or the MAX1044 (see GEO, +9v and -9V from a single battery).

best...
~ Charlie

[brett]

Hi.  I like the Ring Frobnicator, except that it isn't very quiet when you're not playing.

My Dalekator is quiet when you're not playing, because it modulates your signal with itself (ie there isn't any separate modulation tone to "break through").  But that also limits the Dalekator to octave-up ring modulation.  Sooner or later I'll make up a tone generator and try using it with that (the one in John Hollis' Ring Frob is a beaut).  The Dalekator should be a top ring mod once I work through that.

Unfortunately, there doesn't seem to be a good, simple, all-rounder ring modulator available.  

But even as you read this, in a workshop far far away, the search goes on....

[Mark Hammer]

The Anderton one is pretty good.  I've built the EPFM1 and EPFM2 versions.

The nice thing about it is that there are plenty of mods you can do to make it work well for you.  Ring mods are fairly unruly demons, so any circuit that lets you add more control to suit your own needs is better from a playability stance.

Mods well worth considering are a 3-way range switch for the modulating tone.  Modulation just inside the audio range (20-50hz) allows for a tone that is just slightly unpitched, and still permits riffs to be heard as such.  Modulation at higher frequencies (50-200 hz) will allow for something that becomes more pitched as you go higher, and more unpitched as you go lower.  Higher modulation rates produce the whacked out I-have-no-idea-what-that-note-is-supposed-to-be tones.

The nulling trimpot is one of those cases where a multi-turn is well worth the money.

Shaping the tone of the carrier signal (guitar) so that it is steady and closer to sinusoidal helps the RM to behave.  In the EPFM2 unit, you'll see a series resistor and diodes to ground between the input stage and 565.  Those diodes clip the signal for a steady level, but they also introduce some harshness that could be improved upon.  

One way to do this is to stick a passive lowpass filter between the input stage and the diodes.  Using the f=1/(2pi*R*C) formula, take the series resistor that Craig discusses varying for different input levels, and divide it up into 2 or 3 components that add up to the same overall resistance.  From their junctions, run a cap to ground to filter off high end.  Aim for a cutoff frequency around 2-3khz.

There are plentyof other mods you can do too, but I'll leave this posting short and sweet.