I’m curious what happens when you patch the LFO Out to the Carrier In. In particular, using a square wave, what is the effect of the mix knob? Does it still change the amplitude envelope?
Just patched it up and the Mix knob still regulates the amount of modulation but the LFO Amount knob doesn’t do anything (of course).
Does it act the same as when you us the internal carrier? With my old ring mod I found that the shape of the tremolo effect changed based on where the mix knob was set. Mix on 10 was triangle shaped, mix on 5 was the same except it was half the speed, mix on 6 had a slight hiccup to the sound, as did mix on 4.
It is a behavior of the mix knob that never made much sense to me.
Thanks!
After some more experimenting I noticed a change in behaviour with the Mix knob on 4. It cuts out the input signal and you only hear the squarewave modulated sound.
Edit: the same thing occurs with the internal carrier. I can’t replicate the other things you mentioned.
I’m not exactly sure of what you asking here. Using the LFO out as the carrier will produce temolo effects in much the same way as if you set the frequency of the carrier to LFO levels which at sub audio levels will produce a tremolo effect. A square wave will produce a “trill” like sound like flipping a switch off an on.
I am not sure what you mean by amplitude envelope. Using a carrier in simply substitutes the carrier signal from the internal oscillator inside the ring mod for an external oscillator. An amplitude envelope, like you find on other foogers such as the low pass, provide the amplitude contour of the signal. That is not what ring modulation is really doing. It’s actually using the modulator to modulate the amplitude of the carrier. You can find this in the manual and if you don’t have one you can download it.
I hope this helps.
Right, a square wave as carrier gives an on/off envelope to the amplitude. However, at different settings of the Mix knob the behavior is (probably) different. With the internal carrier you can change the tremolo effect based on the Mix knob setting. I’m curious how the Mix knob affects the tremolo effect when you use a square wave as the carrier.
Sadly, I sold my ring mod before really exploring alternate LFO sources for the carrier signal.
It always seemed to me that the mix had trouble blending a dry signal with a bunch of funny stuff, and that when using only 40% of a wild lfo waveform, it would seem to alter the frequency. I assumed this had to do with how the attenuated waves (around 12 o’clock) mixed a little differently than when bein pushed to ten.
Of course, patching Carrier Out to Rate in could generate some interesting sounds
Brian,
I just tried this our with interesting results.
First, for the tone I used the Voyager, which was already set up to run thru the 102’s audio, to the delay, both set to dry signal.
I opened the external envelope allowing for nothing but a sustained tone to pass thru.
I introduced a squarewave courtesy of the VX351 into the carrier in.
Now, what I noticed from the mix knob is that the volume of my overall tone decreased until I reached 5, where the carrier signal, modulated by the square wave woudl be heard. With the Ringmod frequency to low, this was half tone, half trem. So in essence, it faded in a tremelo with the sustained note as I approached the Mix amount of 10, and the sustained tone was almost totally muted by maximum amount as we would normally expect.
Then I introduced the attenuator of the squarewave. Nothing was all that noticable until I switched the ringmod to the HI freq. THen you could hear the clangorous tones modulated at varying intervals as the attenuator knob was turned clockwise.
What is not exactly relevant but interesting to my ears is what happened when I began tweaking the filter of the voyager, whose initial tone was sent thru the ring mod’s audio.
What I began to notice is that with filter resonance, and with the Mix knob on the 102 around 6, the sustained note had glorious harmonic richness unlike I have heard with this filter before. BUT, and I wish I could give a more technical explanation, as the cutoff frequency was in the 3:00 position, as if in between the harmonic waves or intervals, a window would open and I would hear the square waved carrier of the 102. This would appear on and off as I sweeped upwards to 12:00 on the cutoff. If I increased the resonance to about 2:00, this would raise the position in which the carrier of the 102 would be heard, and I BELIEVE it would seperate the distances between that “window”
At full resonance, with the filter wide open interestingly it was nothing but sustained tone, no ring modulation. If I switched to 1 pole, it brought the resonance back.
A very interesting series of harmonic events that Im sure someone could better explain, and Im sure you know WHY these things are such, since your knowledge of synthesis is obviously superior to mine.
I hope that this remotely answers your questions.
Eric
Thanks for checking it out.
When you say ‘Ringmod frequency’ do you mean Mix? The Frequency knob shouldn’t do anything if you are using an external carrier signal.
Then I introduced the attenuator of the squarewave. Nothing was all that noticable until I switched the ringmod to the HI freq. THen you could hear the clangorous tones modulated at varying intervals as the attenuator knob was turned clockwise.
Again, I’m a little confused. I didn’t think switching the ring mod to HI would have an effect when using an external carrier signal.
Brian,
The 102’s frequency POT is set on the first line about 1k (about 12 or 1:00). I had it set there for a patch that I haven’t yet documented, so I didn’t tweak it at all. With the Ringmod Frequency Switch on the LO position, it was half tone/half tremelo.
Switching the switch DOES effect it. It is very similar to the Osc 3 Lo/High switch on the Voyager, even though you might be controling its voltages elsewhere. It functions just as it does when you use the 102 normally.
Isn’t it interesting, just when you think you know what your gear does, you hook it up and find it does something different? Thats why Im a Moogerfooger.
Erik:
Wow! That was an interesting experiment. I am currently away from my home studio so I was not able to experiment with these things. The effect of the frequency know however intriques me. It also confuses me.
I don’t know that much about electronics but I can look at a block schematic and understand it. However, the one supplied in the manual confuses me. You would expect that the mix button is simply a mix between the modulated signal (be it from an external carrier or the internal oscillator). That’s also what the schematic shows.
The schematic shows a switch (which would be flipped when then cable is plugged into the carrier in) between using either the internal oscillator (modulated by the LFO) or the carrier in. However, the mix block ont he schematic does not make any sense to me because the signal flow goes in the wrong direction in some cases. One interpretation is that the carrier is being mixed with the incoming signal which would explain the effects of the frequency.
This one leaves me scatching my head because I can’t understand the block schematic. Perhaps Moog can help on this one.
If you feedback the Ringmod (carrier out to Freq In) then the Mix knob becomes one that switches between octaves.
Are you sure you patched LFO out to Carrier In? It doesn’t really sound like it. The Freq knob and Lo/Hi switch should be out of the circuit.
He patched a squarewave from the VX-351 as I understand it.
Yeah you are correct, I had it in the frequency input.
With the carrier in, my whole previous post is nullified. Thanks for pointing this out.
Cooincidentally, the freq knob, LO/HI switch, and the internal LFO amount and rate are functionless when you use an external voltage source in the carrier in.
I told you you know more about synthesis than me, lol.
BUT, the filter effect is still pretty interesting.
Eric
I think that the differing shape of the tremolo may be caused by wave interference of the input, and output waveforms, which results in beating, which, if slow enough will sound like tremolo. I don’t exactly understand how the ringmod works, as i am not an electrical engineer, but I don know that the modulated signal consists the input frequency + & - the carrier frequnecy. With a low carrier freq, 5Hz, and an input of 262 Hz (middle C) the output would be 257 Hz, and 267 Hz. The two output signals would then beat at 10 Hz (beat frequency = [f2 - f1]), thus a 10 Hz tremolo would be heard, mixing in the input would result in two 5 Hz beat frequencies, which may then interfere with the original 10 Hz beat frequency, producing yet another 5 Hz beat. Which would then mean that with the mix set to ten the tremolo frequency should be twice that of the mix at five, which, based on my experimentation i find not to be so, thus i conclude at low frequencies I do not know how ringmodulation works, any other interpretations will be much appreciated
The mix control with an LFO carrier has never made sense to me. When I got my ring mod I expected it to work like the depth knob on a tremolo pedal, but it definitely doesn’t do that. I need to sit down and work through the math to better understand it.
Ex. Audio is 440 Hz. Carrier is 5 Hz. The sum is 445 Hz and the difference is 435 Hz. If I had three oscillators, one tuned to 440, one to 445, and one to 435 would it sound like tremolo? I guess, though at first glance it looks like it would just sound out of tune. Hmm.
Thinking a bit more. If the mix is on 10, then you’d hear 445 Hz and 435 Hz. If the mix is on 5 (it probably depends on the taper of the pot), then you’d hear an equal mix of 445, 430, and 435. Since the mix knob both increases the wet signal and decreases the dry signal, you can get any combination of 445/435 and 440.
It actually makes sense to me.
So, back to my original question, the mix knob should work the same for a square wave carrier frequency.
Clarity.
Perhaps clarity for you but I will have to think about this some more. Not to complicate matters, but also realize the difference formula for ring modulation is simple with sine waves which but when the carrier becomes complex, things get more interesting. Saw waves especially are harmonically rich (or phat). But now the two diffeences become multiple differences. I think ring modulators work well with guitars because once the note begins to decay, the waveform becomes more sine wave like and therefore, the ring modulation less harsh to the ear.
If both the carrier and the modutor have many partials, then I am actually not sure what the math gives you at that poing but its probably not pretty. I also find this with sounds. Ring modulation works well with thinner sounds.
I think some experimentation with the MP-201 providing the carrier signal to the Ring Mod is in order.
Can you have the user-defined ADSR envelopes act as LFOs? (i.e., can you have them repeat without some sort of gate signal triggering them?) There are some very interesting tremolo sounds possible, I think.
I think your right. 
It’s why I own Moog products. Digital stuff is frankly boring. I never program a digtal synth and say, I think. I pretty much know what I am going to get. Don’t get me wrong, I like my digital synth but my Moog analogue gear, well, it turns me into the made scientist. A few days away from getting back to my studio but I will try this. In fact, I think I will print this thread and try a lot of stuff. Just learning to use the MP-201 awsome beast that it is.