Best DIY ring modulator? What to avoid?

[blackieNYC]

Man, there's a lot of these out there.  And I'll find in some thread that some just cant tweak out constant noise or LFO.  Sonically, the clips I hear are all wacky and fun.  To achieve some degree of reliability, which one should I build?   I may end up with the thing in a blend/ looper/switcher.  Some say they work best with a little drive or OD in front.  I'd like to have another something in the box- a two stomper. OD, fuzz, or something equally wacky to the ring.   Recommendations?

[digi2t]

String Ringer (Clone of the Lovetone Ringstinger). Hands down. Take no prisoners ringmod, LFO, and a great octave fuzz, all in one box.

Proof;

Build doc; http://www.aronnelson.com/gallery/main.php?g2_view=core.DownloadItem&g2_itemId=47423

I really should sit down and vero this for the non-etchers, like me. It's a great ringmod.

[Mark Hammer]

For me, there are a couple of features you want in a ring modulator:

1) "Carrier nulling": That is the ability to attenuate to the point, or near the point, of inaudibility.  Sometimes that can be a simple matter of using a better or 10-turn trimpot to zero right in.  Dedicated noise-gates can help if the RM does not have sufficient nulling capabilities.

2) Something as close to sinusoidal modulation as possible.  Ring modulators were originally used in electronic music with oscillators that could generate pure sine waves, so that all you got was a sum and difference tone.  When the waves become more complex, the number of sums and differences quickly multiply, and the result is noticeably less musical, and more in the realm of noise-generation.  This is true of both the modulation source and the signal.  So if it includes some facility for "rounding off" the audio input signal, that's a good thing.

3) "Drive" is useful insomuch as it sustains the input signal for a long enough time. Distorted input signals simply muddy up the output with too many sums and differences.  Far better to limit the input signal in some way.  I suppose diode clipping can work, but it shold be accompanied by some form of LP filtering.

4) Ability to dial in modulation frequencies just within the audio range.  The higher the modulation frequency, the further apart, and less "pitched" the sum and difference outputs with be.  If that's all you're aiming for, fine.  If you want some ability to produce sounds that are approximately pitched and able to sound like a melody of some sort, albeit with a slightly rubber-band quality to them, then you'll want a circuit, or want to mod the circuit, so that it can modulate below 100hz.  If it can go sub-audio, into the tremolo range, great, but it should at least be able to modulate down to 30-40hz.  If you can dial in the amount of modulation, so that you can add a burr but keep the boing out when you want, even better.

On-board modulation oscillators are certainly convenient, but there is nothing especially wrong with a unit that simply has X and Y inputs and expects you to supply both of them.

[garcho]

#2 and #4, super interesting, thanks Mark!

It's a toy compared to the Stinger, but the LMC567 can do some amazing things. I've got the carrier way down but not out. Hey, faux ring mod in about 5 minutes of breadboarding, might be worth looking at.

[Mark Hammer]

The great thing about carrier bleed in something like the 567 is that it is fixed amplitude.  That makes it a piece of cake to develop a Q&D noise gate targetting that particular source of noise.  Full carrier-nulling is obviously better, but simple optimized gating is a nice 2nd best.  See the early flanger/chorus designs, like the CE-1 or A/DA flanger, for examples.

[cloudscapes]

if you're willing to experiment a little, then a transformer ringmod such as this one:
http://www.cgs.synth.net/modules/cgsrr.html

+ a pre-gain circuit in front of it

+ a carrier signal generator such as this:
http://experimentalistsanonymous.com/diy/Schematics/Oscillators%20LFOs%20and%20Signal%20Generators/Simple%20Dual%20LFO.gif

+ a simple filter (optional), such as this:
http://www.musicfromouterspace.com/analogsynth_new/THE_CAVE/Your%20First%20Synth/Your%20First%20Synth_files/your_first_synth.gif
(the section on the right)

I made a number of ringmods by plugging various circuits onto the transformer thing (first link). I also managed to make carrier bleed much less annoying by gating the output off with a vactrol, driven by the input signal (and boosted).

I'm currently (slowly) working on a new one, but it's DSP based so not really beginner. but it's allowing me to do stuff that can't really be done in analog ringmods,

[blackieNYC]

digi2t - the aronnelson sting ringer - holy crap!  What a build.  I pledge unprecedented sincerity as I now apply the phrase"thanks but no thanks". That thing is cool.
OK, so who's got the 2nd best ring mod in the world?
Thanks for all contributions.  Hamster wheel in brain picking up speed.

[nocentelli]

Ok, going against pretty much all other recommendations (i.e. it's not a proper ringmod, it has some carrier bleed and it can go fuzzy as hell) I'd suggest the Catalinbread Heliotrope as an option to dip your toe in the peculiar waters of ring-mod-ish circuits. It seems to be based on something posted at experimentalists anonymous ("analog bitcrusher"?), has a dead simple opamp w/clipping diodes and gain knob ->JFET with gate wiggled by an single opamp oscilator-> buffer out. The oscillator section has controls that vaguely equate to a mix of sorts, and a frequency-type control that allows you to "tune" the carrier frequency.  


I've tried a few simple ring mod circuits in the past, but hadn't found them particularly easy to get a "musical" sound out of them - Perhaps the nature of the beast. The Heliotrope can do a slight ring-modish edge, fuzzy messed-up squarewave klang mayhem, or most points in between. The carrier bleed is noticeable, but you can easily tune it to the key you're playing in, or get it to form intervals: In the typical ringmod fashion, these sound increasingly alien the further you venture from the note you've set it to. It's a simple one to try out on the breadboard.

[moosapotamus]

You don't necessarily have to build a "true" ring modulator to get that ring mod sound. For example, you could try searching up "Nyquist Aliaser", too. There are CMOS and opamp versions. They aren't true ring modulators, either. More like a pseudo ring mod, as well as the balanced modulator circuits. Not quite the bell/clang sounds that you can get when you put a VCO through it, as opposed to a guitar. But with guitar, they definitely have a ring mod sound that can actually be a bit more musical than a true ring mod.

~ Charlie

[Mark Hammer]

Charlie is correct, of course, and reminded me that you don't have to make a "true" RM to get sounds very much like a RM.  ANY modulation effect, such as chorus, flanger, vibrato, tremolo, Uni-vibe, or phaser, can produce sideband products of a sort if modulated fast enough.

Normally, these effects will be modulated at sub-audio frequencies (anywhere from once every 5 seconds or so to 10 times a second).  If you can identify the capacitor/s that set the overall modulation frequency range, simply cut their value by a factor of 5-10, and the modulation rate will move into the audio range, where you will get "rubber band" sounds (and generally without any carrier nulling problems).

The example I always like to use to illustrate is my old blue MXR rackmount Digital Delay, whose Rate control came with a "pull for x100" function, that would easily produce modulation of the wet signal by as much as 1khz, for a wide variety of RM-like sounds you would not normally expect from a flanger or chorus.

[cloudscapes]

it depends what kind of sounds you're after, too. at higher carrier frequencies, for sure nyquist aliasers and samplerate reducers can sound a lot like ringmods. good enough for a lot of people. but to get that low gong sound that the EHX freq anylizer is so great at, nothing but ringmodulation (or frequency modulation) will do.

kind of like at high LFO speeds, trem and vibrato can sound superficially similar, but at low warble speeds, the differences are clear.

I want to also add that sine waves as a carrier is the best for classical ringmod sounds. you can get sines out of an xr2206 chip with minimal external components. next best is triangle. square for ringmods tends to produce much more carrier bleed.

[pappasmurfsharem]

The sample and hold ring modulator that was designed by someone here IMO is the superior ring mod. On phone can't link to it now, but it is quite lovely sounding .... For a ring mod

[glops]

I really love my Craig Anderton Ring Mod. I think it's a balanced modulator. It sounds terrific and I love the effects loop. I put a 500R trim in series with the 2K null trim and can pretty much completely get rid of the carrier bleed.

I have a partially populated Ring Stinger board that I etched. Gonna slowly work on that. Will be tons of fun I'm sure!

[merlinb]

Jenny Greenteeh also does some ring-mod sounds (low carrier freq):

http://circuitworkshop.com/forum/index.php?topic=1136.msg8939#msg8939
https://dl.dropboxusercontent.com/u/57831278/JennyGreenteethBuildDoc.pdf
https://dl.dropboxusercontent.com/u/57831278/jennygreenteethpcb.bmp

[Paul Marossy]

There's no DIY info on the Black Cat ring modulator, but that one is pretty cool in my book. 

[digi2t]

Here's a link for the Logan 5 ring mod. I originally got it from Forrest Whiteside's site, but unfortunately, it's not there anymore. I'm glad I kept a copy.

http://www.aronnelson.com/gallery/main.php?g2_view=core.DownloadItem&g2_itemId=49709&g2_GALLERYSID=acc0dbad7357767d43cbdacb3203e6cf

I also have a 600 dpi transfer image in the gallery as well, in the same folder.

I combined this baby with a digital octave fuzz in the same box. It's pretty nasty... in a good way. Here's a sound clip, the ring mod comes in at 0:49, and then at 1:15, I flip back and forth between the ring mod on and off.

http://www.soundclick.com/player/single_player.cfm?songid=10490290&q=hi&newref=1

This is the vero of the whole unit;



BOM:
Capacitors C1 22uF   1
Capacitors C11 .001uF   1
Capacitors C2 2nF   1
Capacitors C3, C7 100nF   2
Capacitors C4, C5, C9, C10, C12 .1uF   5
Capacitors C6 10nF   1
Capacitors C8     1
Circuit boards Board   24H x 17R 1
Diodes D1   1N4148 1
Diodes D2   1N4148 1
Diodes D3   1N4001 1
Integrated circuits IC1   CD4070 1
Integrated circuits IC2   LMC567 1
Resistors R1, R3, R8 10K   3
Resistors R4, R2, R6, R7, R9 100K   5
Resistors R5 500K   1
Transistors Q1   2N5089 1

If you draw a line directly under the +9v rail, everything above it gives you a Logan 5 vero. You can then shorten the vero by 4 holes as well. INPUT will be 3 holes up from the +9v, going into C10.

[moosapotamus]

There's no DIY info on the Black Cat ring modulator, but that one is pretty cool in my book. 

I was under the impression that the Black Cat was a clone of the Maestro ring mod, yes/no?
If so... http://www.generalguitargadgets.com/projects/21-filters-other/114-maestro-ring-modulator

~ Charlie

[blackieNYC]

The Logan 5 looks good.  Like a Beavis (which I think I was about to embark on) plus a bit.  Except, I see the actual chip's "output" pin 8 is made use of in the Beavis. Pin 2 is called the loop filter.  Guess that's how this thing is bent.
Nice sample. If I skip the fuzz, it reduces it to a Jessica 6....
So Mark says this is a fixed amplitude carrier circuit - so this bias is not about carrier nulling.  How's the noise floor?
the Nyquist analyzer sounds pretty cool too.  Both simple.  I'm keeping the bar a little low with this one.

[nocentelli]

Here's a link for the Logan 5 ring mod. I originally got it from Forrest Whiteside's site, but unfortunately, it's not there anymore. I'm glad I kept a copy.

Thanks! Are the pot connections reversed? I was looking to make the DOF section, and vol1 and 3 appear to be reversed.

Also, here's a link to the Logan 5 schem if you just want the ringmod bit:

http://i257.photobucket.com/albums/hh218/reverse_engineer/schematics/4aa3f159.png

[digi2t]

Here's a link for the Logan 5 ring mod. I originally got it from Forrest Whiteside's site, but unfortunately, it's not there anymore. I'm glad I kept a copy.

Thanks! Are the pot connections reversed? I was looking to make the DOF section, and vol1 and 3 appear to be reversed.

Also, here's a link to the Logan 5 schem if you just want the ringmod bit:

http://i257.photobucket.com/albums/hh218/reverse_engineer/schematics/4aa3f159.png

The pot connections MAY be reversed. This was one of my early vero projects, and I wasn't paying to much attention to details like that, so buyer beware! Baby steps.