D.I.Y. Ring Modulator?

[bwanasonic]

Aside from Craig Anderton's EPFM, anyone know of a stompbox friendly DIY Ring Modulator schematic/layout they could point me to? How involved/possible would it be to convert Anderton's circuit to a standard 9v power supply? The bipolar thing always seemed like a huge drag to me, esp. for stompboxes.

Or maybe someone will give me a Frostwave Blue Ringer for Christmas...

Kerry M

[jimmy]

you could try tim escobedos thing modulator. its a pseudo ring modulator, so if your looking for a hardcore one, dont bother but if you want an easy easy circuit thatll get you through, its the one for you!

http://www.geocities.com/tpe123/folkurban/fuzz/snippets.html

i think thats it. its on the page somewhere

[jimmy]

you could try tim escobedos thing modulator. its a pseudo ring modulator, so if your looking for a hardcore one, dont bother but if you want an easy easy circuit thatll get you through, its the one for you!

http://www.geocities.com/tpe123/folkurban/fuzz/snippets.html

i think thats it. its on the page somewhere

[moosapotamus]

It would be very easy to adapt Anderton's ring modulator to +9V (single battery) by using a MAX1044 and a couple of 10uF caps, as described at GEO (+9V and -9V from a single battery).

~ Charlie

[Chris Goodson]

It would be very easy to adapt Anderton's ring modulator to +9V (single battery) by using a MAX1044 and a couple of 10uF caps, as described at GEO (+9V and -9V from a single battery).

~ Charlie

The book says it runs off 9volts?  That isn't a single battery?

[Mark Hammer]

I stumbled onto a NOS copy of the EPFM book in a local music store last week (since when did it come with a CD instead of a soundsheet?) and leafed through the non-circuit pages for the first time since I photocopied the best parts from a public library copy some 20 years ago.  As Craig notes, many of the circuits CAN be adapted to 9v but the extra headroom provided by a bipolar supply provides better performance.

Of course there is still the current issue to content with.  I find a great many of the projects in it had the sort of current needs that permitted battery operation, but not with any long-life expectations (e.g., 7-10ma draw is not uncommon).  Drawing what is expected from 2 batteries out of a single battery certainly places it in the tricky range as far as any hopes to provide single-battery operation .  Most certainly one would want to use an adaptor unless otherwise necessary...and if you're going to use an adaptor anyways, why not provide bipolar power?

As a sidenote:  The fastest route to ring modulation sounds is to identify the LFO-rate-setting cap on any modulation effect you happen to have and reduce its value so that the modulation can be shifted from being in the sub-audio range (say around 12hz or less in most such devices) to being in the audio range (20hz or greater).  It isn't a *true* ring modulator but achieves much of the "rubber band" sound that is central to RM tones.  The Hollis Frobnicator uses this trick but the same sort of thing can be applied in many other contexts and types of pedals: chorus, flanger, phaser, tremolo, vibrato, univibe, or anything else that is modulated by an LFO.  As in the case of ring modulators, the higher the modulation frequency, the weirder the tones as sums and differences become less like the basic note.

[Chris Goodson]

I built the CA ring modulator from a PIAA kit and it doesn't seem to work right.  Up until now I had no idea it might use two batteries.  If this is so, how do I hook them up?  
I apologise for sidetracking your post bwanasonic, but I've been wanting to get this thing working for quite a while.

[moosapotamus]

The book says it runs off 9volts?  That isn't a single battery?

No, because it requires a 9volt bi-polar supply, and you can't provide a bi-polar supply from a single battery without some additional circuitry. Most of the circuits discussed here can be powered with +9volts... positive battery terminal to V+, negative battery terminal to ground. For those types of circuits, the schematic will only indicate connections for (+) and (gnd).

But, if you look at the schematic of the Anderton ring mod, you'll notice that it has connections labeled (+), (-), and (gnd). To make a bi-polar supply, the positive terminal from one battery goes to V+, the negative terminal from the other battery goes to V-, and the remaining pos & neg terminals of the two batteries are tied together and connected to ground. If you have a copy of EPFM, check out the section on power.

~ Charlie

[ExpAnonColin]

I'd try looking at modular synth ring mods.  There was some other ring modulator on the net , very simple, but it's lost...  One thing about ring mods is you can get really really simple (Ring Mods ARE really simple things) or you can get very complicated, a la the Moog ring mod.  A simple 3 jack no knob balance modulator is mega easy to build... working on one myself...

-Colin