building a ring modulator

[Hot_Rats]

Could some one help me out with this schematic?:

http://www.synthfool.com/ringmod.html

I want to make it so that:
a) I can plug a guitar into x input, then a bass into the y input to and be playing the multiplied signal through both the guitar and bass amp.
b) In an easy stomp(or two), bypass it completely and seperate the guitar into the guitar amp, and the bass into the bass amp.

Colin, do you have the parts i need or do you know where i can find them?

[Hot_Rats]

is this ring mod different or something? the site says it produces the sum and differences of the two signals. aren't ring mods supposed to multiply?

[expanoncolin]

Ahhh... the classic 'ol passive ring mod

First, you put in your guitar signal to the X input.  It then goes into a 600:600 audio transformer (available from mouser for, I think, 12$), which does a variety of things that gets it ready for ring modulation (I'd prefer not to get into the technical technical things about this-just because it's more complicated than I think I need to).

The Y in is for the carrier voltage.  For the most part, ring mods use internal LFO's for this...  I've tried using a second guitar as the carrier voltage, and lemme tell you, it doesn't work at all.  So basically you're going to need to build a small waveform generator (not too hard, it can be done with transistors, diodes, op amps, 555s, you name it).  This also has to be at a reasonably high level.

Then the 2 of them are all wacky modulated all over the place courtesy of the transformers and diode rings until they come out as the sum and difference of the 2.  (Don't think of it as 200hz+500hz=700hz, think of the waveforms actually being ADDED and SUBTRACTED from the other waveform... even though that IS how ring modulators work, I still think it's much more helpful to think of it in terms of waveform... I mean, a square wave carrier sounds a ton diferent than a sine wave).

Then, there's that other transformer, which outputs it.  Lots of tweaking must go into this design.  Next in line after the tremolo and analog delay is a 633 OR diode ring based supercomplex waveform converter/ring modulator.  It's all drawn out in my head,  but you know, you have very little time when you type up long descriptions of how ring modulators work all the time on the 'net

Hope that helped.  I highly recommend that you use a different design (633JN based), just because this one takes a lot of external considerations.

-Colin

[Hot_Rats]

wow, thanks for the indepthness. that is some really good info.

The title of this thread is a little misleading. I am more interested in building an effect that involves interaction of two people more than ringmods, even if the interactive effect is a ring mod. What else is there?

The bassist is not interested in distortion at all, so this passive ring mod would not be good at all, since it will not produce the effect without a lot of gain. (But just keeping this in mind, it would work but i just need to boost both signals before going into it, correct?)

I have two yahmaha keyboards. Me and a friend often mess around with them together, would this be a better application for the passive ringmod since the keyboards already have a preamp?

[expanoncolin]

Noooo problem.


Hmm... interaction between the two...  You mean that one messes with the other?  I suppose you could have one drive an envelope for an oscillator and an op amp for the other and vice versa... exactly what kind of effect are you looking for, and do you want it to be noisy or more pleasant?

(I deleted your double post-god, being a moderator is useful )

-Colin

[Hot_Rats]

exactly what kind of effect are you looking for, and do you want it to be noisy or more pleasant?

the noisier the better.

[expanoncolin]

exactly what kind of effect are you looking for, and do you want it to be noisy or more pleasant?

the noisier the better.

Oh... well in that case, I recommend getting 2 555 oscillators (pretty easy to make, lots of schems on the net) and make an LDR-based envelope control...  then feed that into a dual op amp.  Now repeat for the other input... basically the distortion and oscillation insanity is determined by the other person's playing.

-Colin

[Hot_Rats]

ive decided on building two fuzzfaces into a box with the passive ring mod. bass player doesnt care about the fuzz because the finished product is not going to be a real bass tone anyway. if the ringmoded guitars fail, ill still have two fuzzfaces and a rind mod for keyboards. ive been wanting to build fuzzfaces anyway because ive never actually built a pedal, and those are good starter projects.

no way am i going to spend money at radioshack. where can i find parts i need?

i think i have the fuzz faces under control. could you reccomend what transisters to use?

also, the passive ring mod calls for germanium diodes. why cant i use silicon ones? where can i find germaniums?

[expanoncolin]

I think 2 fuzz faces in a box would be unnecessarily fuzzy, I'd use 2 LM386's, but that's just me.

Try mouser for everything.  Get 600:600ohm audio transformers.

Germanium diodes are available at a variety of DIY radio sites because in order to make a coil radio like that you need the speed of the germanium ones... It's almost always safe to say that if the circuit asks for germaniuma nd it's not more than a few years old, you NEED germanium.

-Colin

[Hot_Rats]

I think 2 fuzz faces in a box would be unnecessarily fuzzy, I'd use 2 LM386's, but that's just me.

well one is for the x input the other is for the y input.


thanks for all the help. mouser it is.

[expanoncolin]

I think 2 fuzz faces in a box would be unnecessarily fuzzy, I'd use 2 LM386's, but that's just me.

well one is for the x input the other is for the y input.


thanks for all the help. mouser it is.

Well, Fuzz faces would really create a ton of distortion, and THEN be even further distored by the diodes... plus, the output of fuzz faces isn't loud enough, because they're limited by the diodes...  I'd highly recommend an op amp amplifier design.

-Colin

[Hot_Rats]

Well, Fuzz faces would really create a ton of distortion, and THEN be even further distored by the diodes... plus, the output of fuzz faces isn't loud enough, because they're limited by the diodes... I'd highly recommend an op amp amplifier design.

i gotcha. fuzz faces are more about the fuzz not boost, and i need a boost.

i gonna check your links for schematics of opamp type boosts.


really, this is a lot of help. Thanks.

[expanoncolin]

Try, for both inputs, an LM386 wired like this:
Ground to 2 and 4
Input to 3
Electro cap from 1 to 8
output from 5
6 to 9v battery

And that's that.

That should work OK.

-Colin

[pilotcp]

The Y in is for the carrier voltage.  For the most part, ring mods use internal LFO's for this...  I've tried using a second guitar as the carrier voltage, and lemme tell you, it doesn't work at all.

I was reading this thread, and it all sounds very interesting, but i have two questions...with the "it doesn't work at all" i was just wondering what the results were of that test
on a bass guitar forum that i got to a lot was discussing using a Nord MicroModular as an effect processor, and a guy said

Regarding an octave: it has a ring modulator module. If you feed the clean bass signal into both inputs of the ring modulator, you'll get an octave up. I'd be interested to play around with it to figure out a way to do pitch-shifting. I want one of these!

so if i were to wire the input jack to both the inputs for the RM, would that actually set it up an octave?
my logic says no, because with the addition and subtracting of two identical waveforms, you'd get no effect at all, but i am by no strech of the imagination smart

so what do you guys think?

[SpectralJulian]

The second type, which used to be the only way, is the passive type, using transformers, as you have found on the synthfool page.  Seems so simple, eh?  I believe that there are no longer any products in production using this "diode ring" pattern (that's were the term ring modulator came from-notice that the diodes form a ring).  The Lovetone ring stinger, when it was made, was, according to vlad, the maker of the effects, the only diode ring based ring modulator in production.

Zvex now makes the ringtone, which uses a diode ring.[/quote]