MF-102 as an oscillator

[newname]

this idea will work using my 102, Rogue, and a CP-251 (and its attenuator). Right?

yes, that's right. btw, there is much fun to be had when you 'scale' the 102's oscillator differently from your keyboard - the nature of ring modulation is such that you'll find that sounds become 'clangy' and then resolve at various points on the keyboard... sometimes it'll sound like a chord, sometimes like a bell, sometimes very electronic.

I just don't have a 251 to try it out... looks like that will be my next "gear" purchase, not just for the attentuator, but all those CVs will be fun to mess with.

the 251 is definitely a cool tool, i get a lot of use out of mine.

check these out:

http://moogarchives.com/portapot.htm

portapots are attenuators, built very quickly with no case and very little soldering.



good luck!

x

[eric coleridge]

One other easy device to make is a voltage pedal. Just take a 9volt battery and a 9volt battery connector from radio shack and solder it to a male 1/4" jack. I believe positive goes to the tip and negative goes to ground. Then plug the jack into the input of a volume pedal. Now the output of the pedal will be 9volts attentuated by the pedal. This will let you use CV inputs(as opposed to pedal inputs) on older Moogs. Many inputs are meant for +5 to -5 volts, and it might not be good(I'm not sure) to give them 9volts so just use an old battery that is only putting out 5 volts...

The only problem with this device is it only spans the positive range of the CV input.

Does anyone know how to make it range the negative values?

[Rogue]

Thanks for the replies.

check these out:

http://moogarchives.com/portapot.htm

portapots are attenuators, built very quickly with no case and very little soldering.

But, would I need such a "port-a-pot" with stereo connectors? Being that the keyboard out on the Rogue and the frequency input on the 102 are both stereo. How do I make one? There's not much found through a Google search. Just a lot of info about portable toilets

[eric coleridge]

But, would I need such a "port-a-pot" with stereo connectors? Being that the keyboard out on the Rogue and the frequency input on the 102 are both stereo. How do I make one? There's not much found through a Google search. Just a lot of info about portable toilets

I think the Keyboard Out on the Rogue is both input and output; that's why it's "stereo". You don't have to use a ring/tip/sleave stereo cable unless you are making use of both in and out at the same time. It's probably written underneath the jack, or in the manual, which is ring and which is tip. Ring and tip, in case you don't know, refer to the jack itself-- just read the manual (if you haven't already)for your Moogerfooger or Rogue: they're both very well written, and this info is describe there.
with the Moogerfooger, the stereo type jack is implemented for a different reason, but again, it is not necessay to use stereo cable.

To make one of these port-a-pots: simply buy male and female Mono 1/4" jacks, and a potentiometer. I think the pots are maybe 100K or 50K value (same values you would find inside Moogerfooger exp. pedal--same purpose). It would'nt hurt anthing to use a different value-- but these 100K would work the best probably. Just solder them all together the way they look in the picture: the Male jack tip to input of Pot- Pot output to tip of Female jack. you might connect the grounds together too.

[Rogue]

Alright, thanks. That seems to make sense. If anything, my stepdad is an electrician, he might be able to help me put it together properly. I'm pleased to hear that what I need to attenuate the Rogue's CV output for the 102 is relatively inexpensive. I can find the parts I need at RatShack? I would still like to get a CP-251, but considering the cost...

One thing though. The 102 has stereo jacks for such things like Freq, Mix, Amount, and Rate... right? Or am I totally off. I have the manual somewhere, but it's somewhere in a box. I see that the tip is the "keyboard out" for the Rogue. So if the tip is a CV input on the 102's Frequency jack, then all is well? I'm asking because I seem to recall that the expression pedals use stereo jacks. Thanks again for the help, I do appreciate it! I just dont know much about this stuff. And I don't know anyone close by who knows about old synths and CV and stuff. (I do know some people who are anywhere from a few hours to a few days' worth driving distance away... hehe.)

[newname]

hey spike, sorry about the delay - my spamfilter sent the email alert to my trash.


also - i wanted to congratulate you on your cool moog rogue box. that's a really nice piece and reminds me of the case my dad helped me make for my first synths. :)

Alright, thanks. That seems to make sense. If anything, my stepdad is an electrician, he might be able to help me put it together properly.

the things he needs to show you aren't very time consuming. as an electrician, his knowledge focus is a bit different from electronics, but he can definitely give you a good grounding [bad pun there] on the basics of electricity.

he'll probably be flattered if you ask him to explain Ohm's Law. :)

I'm pleased to hear that what I need to attenuate the Rogue's CV output for the 102 is relatively inexpensive. I can find the parts I need at RatShack? I would still like to get a CP-251, but considering the cost...

yes. you can buy a single potentiometer at radio shack to do this. beyond that, it's just how you choose to wire it up:
1-make a patchcord that has the attenuator built into the middle or end of it.
2-duplicate the porta-pot as in the pictures
3-mount the pot inside the rogue [most work of all]

each solution uses slightly different techniques - to do the first you'll need to cut, strip and tin wires, then solder things together and improvise insulation and strain reliefs for the cable.

to do the second, you'll want to use a pair of pliers and possibly short lengths of wire. building something like an actual portapot has more in common with making jewelry than making electronics.

to do the third, you'll need to disassemble the rogue, drill a hole in the back, maybe add a switch and additional wires so that you can bypass the pot if you want to...

One thing though. The 102 has stereo jacks for such things like Freq, Mix, Amount, and Rate... right? Or am I totally off. I have the manual somewhere, but it's somewhere in a box.

well dig it out! your manuals should always be together and somewhere you can get at them fast. you will eventually have a library of manuals and texts that you will need to refer to frequently. get into the habit. it will pay off!

back to your actual question - no, you are not totally off, but these 3 conductor jacks are not wired as 'stereo' jacks. the ring delivers a static [5v?] voltage to a device, the tip sends a variable voltage into to the mooger, and the sleeve is the ground.

the moogers are designed so that if you insert a 2 conductor plug into the 3 conductor CV jack, it will short the voltage - you can still send and receive control voltages, but 'self powered' devices such as expression pedals will no longer work.

if you run a mooger CV output to a mooger CV input using 3 conductor cable, the ring voltage is not shorted.

I see that the tip is the "keyboard out" for the Rogue. So if the tip is a CV input on the 102's Frequency jack, then all is well? I'm asking because I seem to recall that the expression pedals use stereo jacks.

wow, that's interesting.

well, if you are correct about tip=voltage out and ring=voltage in, that means that when you plug in a patchcord two things will happen: the keyboard voltage will indeed change the pitch of the 102's carrier oscillator, and the rogue's VCOS will be sent an unattenuated 5volt signal. moogs use a linear voltage that is scaled 1v/octave, so that means your VCOS will suddenly jump up 5 octaves, or as close to 5 octaves as they can pull off. this could be useful if you use the rogue to frighten dogs, summon bats, that sort of thing. :)

you'll need to either make a special patchcord for the rogue's 'keyboard out' or purchase an 'insert cable' from HOSA or radio shack. this way you'll have two plugs coming out of the rogue, one will be CV in, one will be a CV output _from_ the rogue's keyboard.

Thanks again for the help, I do appreciate it!

no prob, spike. it's good to see that folks like you are out there figuring out how to do this stuff.

ping me offlist if you need any more detail on this.

x

[eric coleridge]

One thing though. The 102 has stereo jacks for such things like Freq, Mix, Amount, and Rate... right? Or am I totally off. I have the manual somewhere, but it's somewhere in a box. I see that the tip is the "keyboard out" for the Rogue. So if the tip is a CV input on the 102's Frequency jack, then all is well? I'm asking because I seem to recall that the expression pedals use stereo jacks. Thanks again for the help, I do appreciate it! I just dont know much about this stuff. And I don't know anyone close by who knows about old synths and CV and stuff. (I do know some people who are anywhere from a few hours to a few days' worth driving distance away... hehe.)

Spike:
Just start connecting your pedal to the output of the Rogue. You can do alot of interfacing with just the two Moog products. You know? Don't necessarily worry about what you don't have yet. You might find that these two Moogs do everything you need them to.
If tip is output on the Rogue, you can plug it into any of the inputs (or outputs- it just won't do anything) on your Mooger (I forget which one you have). You'll be amazed how well they respond to each other.
If you get a stereo cable from radio shack, you can access the "ring" teminal CV In on your Rogue. Then you'll control the Rogue's pitch with you Mooger. But, you'll have to trigger the gate in order to hear the Rogue: So, just hold down a key.
Anyway, you'll figure it out... just start trying different combinations, there's nothing that you can doi "wrong", in other words, you can't harm anything by just making copnnections.

[Rogue]

Thanks again for the replies. I'll have to come back to this soon and experiment, when I have more free time on my hands. I'm hoping my stepdad will be able to help me as I'm not too sure about soldering stuff... easy as it probably is

Eric... I don't have an expression pedal. Not yet anyways I do have a sustain pedal that I got with my Yamaha DX-11, though that uses a ¼" mono jack instead of a stereo jack.

[GregAE]

Folks -

The whole 'Ring Modular as an oscillator' thing was covered in detail a few months ago on the SquareWave site, in an article called "Lord of the Ring (Modulator)". When the RingMod article was posted, we made an announcement in this forum:

http://www.moogmusic.com/forum/viewtopic.php?t=2288


- Greg

[Rogue]

GregAE, your group's article is what inspired me to see if this thing would work with my Rogue Moog The extra osc feature was mentioned a few times recently. So I searched around and found this topic, and I bumped it back up. I'm really grateful for all the knowledge you guys are sharing about these crazy-cool pieces of analog fun. I can't wait to build an attenuator and give it a spin! (Yeah, I haven't made it yet...)

Also, I joined the Squarewave group just to download and read that article on the 102. I don't even have a Minimoog Voyager...