ring Modulator Distortion Problems

Dom Beken · Post by **Dom Beken** » Sun Oct 22, 2006 7:40 pm

I've just bought an MF-102 Ring modulator and the Murf... a whole world of fun and I can't wait to get hold of the Command module thing and a MIDI-CV converter to try and get the LFOs synced....

It's all good until I try and use an external carrier on the ring modulator. Firstly, before it has any effect the input has to be REALLY hot, and as soon as it starts modulating the input the result is really distorted. I would describe the output as a heavilly distorted version of the input with vague properties from the carrier - which are only really noticeable of you use an unconventional carrier signal such as speech! Using the internal carrier is fine.

I've been trying to use my Midi moog sine wave as a carrier and something like a hammond as the main signal hoping for cool and odd ring modulations by sweeping the frequency of the MIDI Moog sine wave (something like the manual suggests!) By the time I've turned up the MIDI Moog hot enough to hear any effect it's a very distorted mess.

Is this user error... is this how it's supposed to sound, or should I send it back?

Any help appreciated!

latigid on · Post by **latigid on** » Mon Oct 23, 2006 5:44 am

I was trying this a few years ago too. I asked Amos (the head tech) and he said to adjust a trimpot inside the unit. I forget which one, so you should probably contact him yourself. It's best to ask through the website ( http://moogmusic.com/contact.php ) as he usually doesn't reply to emails. It might just be me though!

eric coleridge · Post by **eric coleridge** » Tue Oct 24, 2006 7:19 am

It could be that the sine wave is not an ideal carrier signal. I think for more typical ring-mod type effects it's better to use a waveform with more harmonics. You probably have to overdrive the sine wave to the point of distortion before it exhibits much of any effect as a modulator; which sounds like what you've described.

Try using a different carrier signal, just to make sure the problem isn't with the carrier input.

OysterRock · Post by **OysterRock** » Tue Oct 24, 2006 1:04 pm

eric coleridge wrote:It could be that the sine wave is not an ideal carrier signal. I think for more typical ring-mod type effects it's better to use a waveform with more harmonics.

The mf-102's internal carrier signal is a sine wave. Most ring mods use a sine wave as the carrier signal. Using a more complicated waveform (such as a square wave) as the carrier will give you a MUCH more complicated output (mathematically complicated at least). Only experimentation can tell you if you think it sounds better, but I tend to think a square wave carrier sounds much less pleasant than a sine wave.

eric coleridge · Post by **eric coleridge** » Tue Oct 24, 2006 3:41 pm

OysterRock wrote: The mf-102's internal carrier signal is a sine wave. Most ring mods use a sine wave as the carrier signal. Using a more complicated waveform (such as a square wave) as the carrier will give you a MUCH more complicated output (mathematically complicated at least). Only experimentation can tell you if you think it sounds better, but I tend to think a square wave carrier sounds much less pleasant than a sine wave.

Are you sure about that? I'm fairly certain that the internal carrier wave on the MF102 is a triangle waveform (which is also true of the LFO-- even though it's labeled on the panel as a sine-wave).

I thought it was more typical for Ring Mods to use square waves as their carrier signals (or at least those ones that have an internal carriers at all). I know this is true for both the MS20 and the Arp Odyssey which tap the sqaure waves from their internal oscillators for use in their ring-mod circuits. I don't know of any other ring mods where the carrier is already pre-wired, besides some other guitar pedal RMs. Which RMs are you taliking about that use a sine-wave as a carrier?

Regardless, I could be off about this guy's problem. But it seemed to make sense.[/list]

OysterRock · Post by **OysterRock** » Tue Oct 24, 2006 8:22 pm

eric coleridge wrote: Are you sure about that? I'm fairly certain that the internal carrier wave on the MF102 is a triangle waveform (which is also true of the LFO-- even though it's labeled on the panel as a sine-wave).

Positive. The LFO is a triangle, the carrier is a sine. Use it as control voltage and listen.

I know this is true for both the MS20 and the Arp Odyssey which tap the sqaure waves from their internal oscillators for use in their ring-mod circuits.

I don't know about the korg and arp, but I know ring mod pedals almost always uses a sine wave as a carrier.

eric coleridge · Post by **eric coleridge** » Wed Oct 25, 2006 8:55 am

sounds like a triangle

OysterRock · Post by **OysterRock** » Wed Oct 25, 2006 9:07 am

I stand corrected. Check out the "Lord of the Ring Mod" article. Huh, I was positive it was a sine. Well, all the ring mod schematics I've looked through use a sine wave as a carrier.

A triangle wave is very close to a sine, on one or two more harmonics. They're even labeled as sine waves on the ring mod. It is not going to sound as different from a sine as, say, a square wave which has numerous harmonics.

vitalijkopz · Post by **vitalijkopz** » Tue Dec 12, 2006 2:35 pm

Dom Beken wrote:I've just bought an MF-102 Ring modulator and the Murf... a whole world of fun and I can't wait to g...

The good fellow .

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