Results 1 to 20 of 20

Thread: analogue ring modulator

  1. #1
    New Member
    Join Date
    Apr 2016
    Posts
    4
    Thumbs Up/Down
    Received: 0/0
    Given: 0/0
    Rep Power
    0

    analogue ring modulator

    Hi guys, first post here.
    So im about to do my first year project for my bachelor and i decided to make a case with 3 electromagnetic microphone inputs that can modulate each other in real time.
    we have received fairly basic knowledge about this in our classes, but havent really expanded further on the topic other than making a basic board with oscilliators, an output and a volume know basically.
    So we're supposed to make research on the thing we want to build which is what im trying to do here.
    I would be really grateful if some people here could give a helping hand with the schematic itself. according to my teacher I was consulting last week, it should be possible to directly wire the inputs together to create a ring modulation effect. But since im not that hard on reading schematics yet, I can find out exactly how it would need to be wired together.
    Hopefully I created this in the right place and I hope you have some insight on this topic since im pretty green on basic electronics.

    0 Not allowed! Not allowed!

  2. #2
    Old Timer Leo_Gnardo's Avatar
    Join Date
    Sep 2012
    Location
    Dogpatch-on-Hudson
    Posts
    6,400
    Thumbs Up/Down
    Received: 1,418/21
    Given: 1,207/0
    Rep Power
    14
    Quote Originally Posted by YAMI View Post
    according to my teacher I was consulting last week, it should be possible to directly wire the inputs together to create a ring modulation effect.
    There we go with "theories" again... if mixing inputs caused a ring mod effect, that would cause ALL the mixes that have ever been made, live on-the-fly as well as recorded - to sound awfully weird. On the other hand, ring-mod-like effects can be created without any electrical inputs at all to a mixer. Too bad you can't get a front row seat at a concert by The Roches, you'd hear plenty of it. They don't often perform these days, but when they did, oh boy! Himalayan and Tuvan throat singers also carry it off, these days there's a couple of recordings you can find by overtone choir Prana, one is "Gathering In The Light" with Baird Hersey and Krishna Das, a good example of ear-busting modulations done "in the air", simply recorded for your listening pleasure & consternation. Listening on youtube, it's apparent the sound doesn't translate all that well: the modulations show up as distortion, but yet they are there. The sound is perfectly clear on their CD's. Recordings of vibraphone & marimba often display this type of modulation as well.

    Another example is reflection of sound off a rotating moving surface, say bouncing sound waves off of fan blades, that gets a ring mod effect all right.

    I'd say before reading schematics, maybe some reading up on Harald Bode, the father of the electronic ring modulator would be in order. He was a contemporary of Robert Moog and developed some instruments of his own. When I worked at the SUNY Albany electronic music lab, there was a Bode ring modulator atop the rack of Moog modules. It took a deft touch to use it well, as it could turn audio into annoying ear racket very easily. Those rare individuals who could use it well, got some amazing sounds in their compositions.

    Perhaps your prof. is referring to the sum & difference frequencies that result from mixing audio signals, I guess that's a rough form of modulation, but hardly compares to the subtle through startling effects that can be accomplished with an electronic ring modulator.

    0 Not allowed! Not allowed!

  3. #3
    Lifetime Member Enzo's Avatar
    Join Date
    May 2006
    Location
    Lansing, Michigan, USA
    Posts
    32,160
    Thumbs Up/Down
    Received: 1,890/7
    Given: 0/0
    Rep Power
    55
    In fairness, he didn't say mixing inputs, he said wiring them together. I can imagine two voltage sources wired in series causing some intermodulation.

    You should research how ring modulators function. If we suggest schematics, you still won;t know why our schematic works. If you can get two signal sources of any sort to modulate one enother, then adapting that to microphone or other audio sources won't be the maqin challenge.

    0 Not allowed! Not allowed!
    Education is what you're left with after you have forgotten what you have learned.

  4. #4
    New Member
    Join Date
    Apr 2016
    Posts
    4
    Thumbs Up/Down
    Received: 0/0
    Given: 0/0
    Rep Power
    0
    Quote Originally Posted by Leo_Gnardo View Post
    There we go with "theories" again... if mixing inputs caused a ring mod effect, that would cause ALL the mixes that have ever been made, live on-the-fly as well as recorded - to sound awfully weird. On the other hand, ring-mod-like effects can be created without any electrical inputs at all to a mixer. Too bad you can't get a front row seat at a concert by The Roches, you'd hear plenty of it. They don't often perform these days, but when they did, oh boy! Himalayan and Tuvan throat singers also carry it off, these days there's a couple of recordings you can find by overtone choir Prana, one is "Gathering In The Light" with Baird Hersey and Krishna Das, a good example of ear-busting modulations done "in the air", simply recorded for your listening pleasure & consternation. Listening on youtube, it's apparent the sound doesn't translate all that well: the modulations show up as distortion, but yet they are there. The sound is perfectly clear on their CD's. Recordings of vibraphone & marimba often display this type of modulation as well.

    Another example is reflection of sound off a rotating moving surface, say bouncing sound waves off of fan blades, that gets a ring mod effect all right.

    I'd say before reading schematics, maybe some reading up on Harald Bode, the father of the electronic ring modulator would be in order. He was a contemporary of Robert Moog and developed some instruments of his own. When I worked at the SUNY Albany electronic music lab, there was a Bode ring modulator atop the rack of Moog modules. It took a deft touch to use it well, as it could turn audio into annoying ear racket very easily. Those rare individuals who could use it well, got some amazing sounds in their compositions.

    Perhaps your prof. is referring to the sum & difference frequencies that result from mixing audio signals, I guess that's a rough form of modulation, but hardly compares to the subtle through startling effects that can be accomplished with an electronic ring modulator.
    ill look into that, thanks.
    Hmm I guess it would be better to make a "main channel" and use the other 2 inputs as carriers?

    0 Not allowed! Not allowed!

  5. #5
    Supporting Member
    Join Date
    Dec 2009
    Location
    UK
    Posts
    3,471
    Thumbs Up/Down
    Received: 201/0
    Given: 27/0
    Rep Power
    14
    There are a few 'classic' ring mod circuits - I've built several using transformers, but prefer the AD633 chip approach and this is what I've used in my latest synth build. The usual scenario is either a single audio source and variable (or even fixed) frequency oscillator, or two audio sources. Three interactive audio sources is an interesting challenge.

    0 Not allowed! Not allowed!

  6. #6
    Lifetime Member Enzo's Avatar
    Join Date
    May 2006
    Location
    Lansing, Michigan, USA
    Posts
    32,160
    Thumbs Up/Down
    Received: 1,890/7
    Given: 0/0
    Rep Power
    55
    What you haven't done, at least for us, is define what you want this thing to do. I mean "I want to make a ring modulator" is not very specific. Sorta like "I want to build a sound improver". SO to propose making one a main channel and so on still doesn't help us, so we cannot give meaningful help.

    0 Not allowed! Not allowed!
    Education is what you're left with after you have forgotten what you have learned.

  7. #7
    Supporting Member eschertron's Avatar
    Join Date
    Aug 2012
    Location
    Great Black Swamp
    Posts
    2,256
    Thumbs Up/Down
    Received: 441/0
    Given: 1,177/1
    Rep Power
    11
    In my limited understanding of a ring modulator, it is defined as a "four-quadrant multiplier", which in plain speak means that each of two signals is a carrier, and also a modulator for the other.
    To get a feel (er, or rather, ear) for what ring modulation is, I imagine there are plenty of youtube examples (haven't looked). Plus, any decent digital recording rig has to have a plug-in or two for the effect. If you have access at home or school to such a setup, you can experiment and get an idea (or even a scope plot) of what ring modulation is. For example, a static carrier sounds much different than a complex signal, and could be easily mistaken for a simple tremolo effect (which is related, by the way, but not identical).

    If the goal is to intermodulate not two, but three independent signals, some thought will need to be given on what that means. A product of the first two signals modulated by the third, perhaps? Was the 3 signals your idea or the profs?
    If you go with something non-standard, the hard part of the engineering might be to decide on the implementation rather than the actual building/tweaking. As advised above by Mick, using an LM633 -- or any of the designs that feature OTAs like the CA3080 (yeah, my college textbook is that old) -- will make the transition into reality much smoother.
    Good luck! Keep us posted, sounds like a fun project!

    0 Not allowed! Not allowed!
    If it still won't get loud enough, it's probably broken. - Steve Conner
    If the thing works, stop fixing it. - Enzo
    We need more chaos in music, in art... I'm here to make it. - Justin Thomas
    MANY things in human experience can be easily differentiated, yet *impossible* to express as a measurement. - Juan Fahey


  8. #8
    Old Timer
    Join Date
    Feb 2010
    Location
    Just south of Bawlmer, Merlin
    Posts
    2,662
    Thumbs Up/Down
    Received: 354/6
    Given: 351/1
    Rep Power
    12

    Greetings from a Kibitzing Bypasser

    The first time I heard a ring modulator in action, I decided that if I ever heard one again it would be too soon.
    I liked a lot of things Don Ellis did, but his intro to Hey Jude was not one of them.
    Thus, I never bothered to investigate how RMs work.



    Wikipedia tells me that a ring modulator (named for its ring of four diodes) multiplies two signals.
    As noted, there are other ways of multiplying two signals; Googling "analog multiplier" shows a bunch of methods.

    Ring modulators
    frequency mix or heterodyne two waveforms, and output the sum and difference of the frequencies present in each waveform. Multiplication in the time domain is the dual of convolution in the frequency domain, so the output waveform contains the sum and difference of the input spectral components. For the basic case where two sine waves of frequencies fcarrier and fvoice are multiplied, two new sine waves are created, one at fcarrier +fvoice and the other at fcarrier - fvoice.
    https://en.wikipedia.org/wiki/Ring_modulator
    https://en.wikipedia.org/wiki/Ring_modulation

    So, you typically have two inputs. If you feed a musical instrument into one input and some random frequency into the other, you'll probably get random dissonance out. If you feed a single instrument into both inputs, or two different instruments playing in unison into the two inputs, I imagine you may produce some interesting tone colors.

    This commercial demo shows that you can get musically interesting output by feeding an oscillator at a frequency related to the music (say the root or fifth of the key of the tune) into the "carrier" input.
    https://www.youtube.com/watch?v=cjzXb0CdSUs

    I'm not sure what you want to do with three microphone inputs.
    Can you explain further (or maybe revise your project concept)?

    --------------------------------------------------

    Quote Originally Posted by Leo_Gnardo View Post
    Himalayan and Tuvan throat singers also carry it off,
    I learned how to get the easiest overtone series at a percussion workshop.*
    Sing "Herrrr" at a low pitch, then gradually shift mouth & throat position to "eeee".
    At some intermediate position, you'll feel and hear various overtones popping out.
    You can shift back and forth, making a sound like an electric razor or hair trimmer with a mis-adjusted blade.
    If you live in an apartment or rowhouse, it's a great way to endear yourself to the neighbors.

    * Percussion WS connection: Sing your low note to match the BMF tuned frame drum; the drum masks your fundamental note, making it sound like you're singing only the overtones.

    0 Not allowed! Not allowed!
    Last edited by rjb; 04-26-2016 at 08:16 PM.

  9. #9
    Supporting Member
    Join Date
    Dec 2009
    Location
    UK
    Posts
    3,471
    Thumbs Up/Down
    Received: 201/0
    Given: 27/0
    Rep Power
    14
    A ring modulator as defined cannot operate on three signals. You can mix signals, but those mixed signals won't modulate each other. Another consideration is that a ringmod has the carrier nulled - it does not appear at the output unless the circuit is imperfect or badly designed. Because of the multiplication, the absence of a signal at either the main or carrier inputs will result in zero output.

    There are a few approaches you could take, but it depends what the purpose of the circuit is. You can string ringmod circuits together in series, that way any input will modulate the others, but the output could end up as mush. You can work out mathematically what the outputs could be.

    As it stands there's too much latitude in your spec - narrow down the purpose as per Enzo's post, and list the must-have critical features of the circuit. My approach is always to do a block diagram that identifies each functional unit and signal paths. It's then easier to design the circuit at each individual stage.

    0 Not allowed! Not allowed!
    Last edited by Mick Bailey; 04-26-2016 at 09:28 AM.

  10. #10
    New Member
    Join Date
    Apr 2016
    Posts
    4
    Thumbs Up/Down
    Received: 0/0
    Given: 0/0
    Rep Power
    0
    thanks for the comments guys, it gave me a much more clear image of what I wanted to do and sorry for my somewhat vague description in the first post.
    The important thing to remember here is that we're novices when it comes to this and our teachers are aware of that, so its mostly for experiemental purposes. Its gonna be used as an experiment more so than an actual "instrument" or effect.
    So the device is a case that on the front consists of 3 electromagnetic mics where you can put different electronic devices on thus using those signals as the audio source.
    in my mind, there's 9 knobs on the box as well. 3 volume knobs for each input and the other six knobs controls how much each source modulate eachother.

    0 Not allowed! Not allowed!

  11. #11
    Supporting Member Jazz P Bass's Avatar
    Join Date
    Dec 2008
    Location
    Wernersville, PA
    Posts
    12,940
    Thumbs Up/Down
    Received: 534/3
    Given: 289/0
    Rep Power
    26
    Just a thought: Quote"im pretty green on basic electronics."

    Why not start off with something a tad less complicated.

    0 Not allowed! Not allowed!

  12. #12
    Old Timer
    Join Date
    Feb 2010
    Location
    Just south of Bawlmer, Merlin
    Posts
    2,662
    Thumbs Up/Down
    Received: 354/6
    Given: 351/1
    Rep Power
    12
    Quote Originally Posted by YAMI View Post
    sorry for my somewhat vague description in the first post.
    I'm still lost.

    Quote Originally Posted by YAMI View Post
    its mostly for experiemental purposes. Its gonna be used as an experiment more so than an actual "instrument" or effect.
    OK, then what's your experiment? Maybe hook up 3 function generators to the inputs and scope the output?

    Quote Originally Posted by YAMI View Post
    So the device is a case that on the front consists of 3 electromagnetic mics where you can put different electronic devices on thus using those signals as the audio source.
    What does this mean? Please name some "different electronic devices". How are they going to interface with your box?

    Quote Originally Posted by YAMI View Post
    in my mind, there's 9 knobs on the box as well. 3 volume knobs for each input and the other six knobs controls how much each source modulate each other.
    How about just the volume knobs? Or, if your inputs are from devices with adjustable outputs, no knobs?
    I would take Mick's advice and draw block diagrams with signal flow from inputs, through the potentiometers (I assume the knobs are attached to pots) to outputs.
    Just how is that control matrix going to be configured?

    Quote Originally Posted by YAMI View Post
    I think you meant to label the knob at 3rd row, 2nd column "Modulation from C".
    But more importantly, where is/are the output(s)?


    PS- In my previous post, I failed to note that commercial ring modulators used for musical applications typically mix the "dry" signal with the modulated output.

    EDIT: I agree with Jazz. Scale way back. Not to be snarky, but it seems you don't know enough yet to know what you don't know. Maybe try using the schematic from Wikipedia as the basis of a standard 2-input ring modulator. You would still have the engineering problems of sourcing parts and interfacing the box to real world devices. And you might want to mix the "dry" input with the modulated output. That would be more than enough of a challenge for a first year project! IMHO.

    0 Not allowed! Not allowed!
    Last edited by rjb; 04-27-2016 at 01:16 AM.

  13. #13
    New Member
    Join Date
    Apr 2016
    Posts
    4
    Thumbs Up/Down
    Received: 0/0
    Given: 0/0
    Rep Power
    0
    Hey guys, thank you so much for your very valuable output. because of your replies I was able to get a really clear image of what I wanna do.
    Im gonna make a ring module with the D633 IC with 2 coil microphones. And the schematic is kinda easy, but ill reply again if I need any assistance.
    Again, thank you for setting me on the right path.

    0 Not allowed! Not allowed!

  14. #14
    Senior Member
    Join Date
    May 2006
    Posts
    3,848
    Thumbs Up/Down
    Received: 203/2
    Given: 20/0
    Rep Power
    18
    I think one needs to distinguish between what counts as a true ring modulator, according to a classic electronic definition, and what sounds like a ring modulator.

    Just about any periodic modulation that occurs in the audio range (as opposed to subaudio) can produce audible sideband products that sound for all the world like a true ring modulator. So, take a tremolo, a vibrato, a phase-shifter, a flanger, a chorus, a swept filter of some kind, and modulate any of them faster than 20hz or so, and they will instantly acquire that "rubber band" quality. What I find fascinating is the manner in which they can each sound so different to us, when modulated at subaudio rates, yet begin to sound so similar as modulation rate goes up. I'll wager that if I set the LFO for 100hz, you wouldn't be able to tell any of them apart.

    Not that they turn into the same thing. Rather, it's a matter of what features of the resulting sound we attend to and perceive most.

    0 Not allowed! Not allowed!

  15. #15
    Old Timer
    Join Date
    Feb 2010
    Location
    Just south of Bawlmer, Merlin
    Posts
    2,662
    Thumbs Up/Down
    Received: 354/6
    Given: 351/1
    Rep Power
    12
    Quote Originally Posted by YAMI View Post
    Im gonna make a ring module with the D633 IC
    I think you mean AD633.
    Google tells me AD633 is an Analog Devices quad multiplier; D633 is either a Darlington transistor or a Moog direct drive servo valve.


    Quote Originally Posted by YAMI View Post
    with 2 coil microphones.
    What are "coil microphones"? Induction loops? Moving-coil (AKA dynamic) microphones?
    What are your anticipated signal sources?

    PS- Thanks for starting the ring modulator thread. I really needed another item on my "maybe some day" hobby project list- to be started after the home repair project list!

    0 Not allowed! Not allowed!

  16. #16
    Supporting Member Jazz P Bass's Avatar
    Join Date
    Dec 2008
    Location
    Wernersville, PA
    Posts
    12,940
    Thumbs Up/Down
    Received: 534/3
    Given: 289/0
    Rep Power
    26
    I found this students project interesting & professionally done.

    Ring Modulator.pdf

    0 Not allowed! Not allowed!

  17. #17
    Supporting Member eschertron's Avatar
    Join Date
    Aug 2012
    Location
    Great Black Swamp
    Posts
    2,256
    Thumbs Up/Down
    Received: 441/0
    Given: 1,177/1
    Rep Power
    11
    Quote Originally Posted by Jazz P Bass View Post
    I found this students project interesting & professionally done.

    Ring Modulator.pdf
    Please note that the project was done in a 400-level course

    0 Not allowed! Not allowed!
    If it still won't get loud enough, it's probably broken. - Steve Conner
    If the thing works, stop fixing it. - Enzo
    We need more chaos in music, in art... I'm here to make it. - Justin Thomas
    MANY things in human experience can be easily differentiated, yet *impossible* to express as a measurement. - Juan Fahey


  18. #18
    Old Timer
    Join Date
    Feb 2010
    Location
    Just south of Bawlmer, Merlin
    Posts
    2,662
    Thumbs Up/Down
    Received: 354/6
    Given: 351/1
    Rep Power
    12
    Wondering what type of oscillator DIY ring modulator users employ for the carrier input, and what kinds of sounds they produce.
    Waveshape, frequency? Variable frequency? Frequency sweep? How controlled while playing?
    I'm guessing my preference would be a variable frequency sine wave generator that could be accurately set to musical pitches.

    I find much of this "musical".
    https://www.youtube.com/watch?v=cjzXb0CdSUs

    I find much of this "not so musical".
    https://www.youtube.com/watch?v=t0hR-HASR6Y

    Advice?

    EDIT:
    Although the Don Ellis (2nd link) is starting to grow on me, I'm asking advice on producing "subtle" vs dissonant in-your-face effects.

    0 Not allowed! Not allowed!
    Last edited by rjb; 04-28-2016 at 06:43 AM.

  19. #19
    Supporting Member
    Join Date
    Dec 2009
    Location
    UK
    Posts
    3,471
    Thumbs Up/Down
    Received: 201/0
    Given: 27/0
    Rep Power
    14
    I feed the ringmod in my synth from two different audio oscillators that will go from a few Hz to just on the limit of my own hearing range. Both can be independently modulated - usually from a pair of LFOs with variable wave shape. With square waves I can also simultaneously modulate the duty cycle.

    The effects are pretty impressive; when set up for a bell/chime/gong sound you'd swear you were hearing something metallic being struck. The sounds are so incredibly musical and in no way dissonant when set up this way and played from the keyboard.

    The other way I like to use the ringmod is to manually shift one frequency against the other and get those dissonant sounds.

    In the same light as a true ringmod, I've played round with bit crusher pedals with guitar - commercially the WMD Geiger Counter and a few DIY builds. I built a guitar pedal using a wah shell that controlled the oscillator frequency and this worked superbly. I put in a switch to select between three ranges. The nice thing is that you can track the fretboard with the pedal to sync the effect. Some strange results came out of this; with the pedal at a certain position you can play an open string and it's the same pitch when fretted at the 12th. Some really nice harmonized notes can be had, too.

    0 Not allowed! Not allowed!

  20. #20
    Lifetime Member Enzo's Avatar
    Join Date
    May 2006
    Location
    Lansing, Michigan, USA
    Posts
    32,160
    Thumbs Up/Down
    Received: 1,890/7
    Given: 0/0
    Rep Power
    55
    rjb, then you would absolutely HATE Karlheinz Stockhausen. I rather enjoyed his works back in my days of...um... consciousness enhancement.

    https://en.wikipedia.org/wiki/Karlheinz_Stockhausen

    0 Not allowed! Not allowed!
    Education is what you're left with after you have forgotten what you have learned.

Thread Information

Users Browsing this Thread

There are currently 1 users browsing this thread. (0 members and 1 guests)

Similar Threads

  1. Worlds First Analogue Optical Guitar Cable - On Kickstarter NOW!
    By Iconicsound in forum Plug Your Product/Service
    Replies: 21
    Last Post: 02-27-2016, 08:56 PM
  2. Peavey Mace VT 2x12 // Sounds like ring modulator, Help!
    By christianbrady in forum Maintenance, Troubleshooting & Repair
    Replies: 3
    Last Post: 09-08-2010, 04:46 PM
  3. amp sounds like a ring modulator? why?
    By yunger in forum Maintenance, Troubleshooting & Repair
    Replies: 5
    Last Post: 02-08-2009, 09:16 PM
  4. budda Super Distortion 30/Ring Modulator
    By booj in forum Maintenance, Troubleshooting & Repair
    Replies: 5
    Last Post: 06-16-2008, 07:41 PM
  5. Help! My amp sounds like a ring-modulator.
    By Humbucker in forum Maintenance, Troubleshooting & Repair
    Replies: 7
    Last Post: 04-11-2008, 03:02 AM

Bookmarks

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •