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jukingeo
Joined: Oct 24, 2007 Posts: 166 Location: The dark side of the moon
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Posted: Sat Jun 01, 2013 8:06 am Post subject:
MOFOS: LFO as a VCO |
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Hello all,
I had a question that sparked my curiosity and I was wondering if the MFOS LFO's frequency range could be altered to be switched from LFO duty to VCO duty, this way you could switch out the LFO if you want another VCO and vice versa.
Now I am well aware that the LFO's probably cannot be calibrated for 1v per octave, but as of this stage of the game (since I been on the fence here at MFOS for a VERY long time), I figured I would forego the use of a keyboard in favor of creating more 'musical noise'. I do want CV control though, for a sequencer and/or sample & hold which is a must have. For that I doubt 1v per octave is necessary, as I have seen the simple WSG hooked up to a sequencer producing quite a bit of 'musical noise'.
As the MFOS LFO's have all waveforms present and it is a simpler circuit than the VCO I was curious if it could do double duty as a VCO. Then as more money permits I can add the proper 1v/octave VCO's.
Thank You,
Geo |
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Skrog Productions
Joined: Jan 07, 2009 Posts: 1196 Location: Scottish Borders
Audio files: 155
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Posted: Sat Jun 01, 2013 8:22 am Post subject:
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Hi there , i have tried my mfos vc-lfo's as osc's using a 5 octave midi keyboard through a midi to cv converter, i found they stayed in tune over a couple of octaves , fine for bass lines .
There is only $3 between the vc-lfo & the 1v oct vco , but you need scope & meters to calibrate the vco. |
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Skrog Productions
Joined: Jan 07, 2009 Posts: 1196 Location: Scottish Borders
Audio files: 155
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Posted: Sat Jun 01, 2013 8:26 am Post subject:
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forgot , the coarse & fine control dials for tuning have a nice sweep from lfo speeds to audio rates |
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jukingeo
Joined: Oct 24, 2007 Posts: 166 Location: The dark side of the moon
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Posted: Sat Jun 01, 2013 10:13 am Post subject:
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Skrog Productions wrote: | Hi there , i have tried my mfos vc-lfo's as osc's using a 5 octave midi keyboard through a midi to cv converter, i found they stayed in tune over a couple of octaves , fine for bass lines .
There is only $3 between the vc-lfo & the 1v oct vco , but you need scope & meters to calibrate the vco. |
So the LFO's already go into the audio range? Is it just bass line range or can they go higher?
Yes, I know that there isn't much a price difference between the LFO and VCO, I was mainly after versatility. Adding an oscillator (or two) to a simple project such as the synth experimenter or noise toaster could expand nicely on a small project and perhaps from there I could get into a full modular when money allows.
Geo |
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Skrog Productions
Joined: Jan 07, 2009 Posts: 1196 Location: Scottish Borders
Audio files: 155
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Posted: Sat Jun 01, 2013 2:58 pm Post subject:
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Hi , yes the vc-lfo goes from 1 cycle 2mins to doggy distressing high pitch .
it is inevitable you will be sucked in by modular lust , none of us have escaped so far , if you are happy making a +12v / -12v power supply then they will be a great start to your very own home made system.
If you are fairly new to diy synth i'd recommend the easier noise toaster or wsg or experimenter first to get the hang of things.
Dave. |
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jukingeo
Joined: Oct 24, 2007 Posts: 166 Location: The dark side of the moon
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Posted: Sat Jun 01, 2013 8:31 pm Post subject:
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Hello Dave,
Skrog Productions wrote: | Hi , yes the vc-lfo goes from 1 cycle 2mins to doggy distressing high pitch . |
Wow! So it really has that kind of range, huh?
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it is inevitable you will be sucked in by modular lust , none of us have escaped so far |
That addicting, huh? Well, for now I do have to keep things at bay cost wise, so I am going to make some compromises and just choose wisely. Thus if the LFO's can double as VCO's then more power to me. I know they are not 1volt per octave, but I decided that is the sacrifice to make. I am mostly interested in CV control via sequencers and sample & hold.
Quote: | , if you are happy making a +12v / -12v power supply then they will be a great start to your very own home made system. |
I am by trade an electronics technician for close to 25 years now, so I certainly can put together just about any of the MFOS boards. Cabinet and face plate construction would be my shortcomings though. I have made a few posts in the past if you search using my forum name. I have been for a very long time on the fence.
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If you are fairly new to diy synth i'd recommend the easier noise toaster or wsg or experimenter first to get the hang of things.
Dave. |
I was actually thinking along those lines as well. I am thinking of something 'all in one'l, just to 'get in'. While it does seem going straight to modular would be the course of action for me, it is the high cost (in terms of money and time invested) just to get all the pieces together for a full modular that stops me. I would rather get something small that I can expand on.
Since the Experimenter looks to me like two Noise Toasters in one package since it has two of everything AND it is already patched out it would seem like a logical choice, especially if I team it up with one or two of the modular LFO's.
The WSG looks good as an initial building block too since it has SIX oscillators AND a full filter on board. I heard some seriously sweet drones from this little box. The drones seem to be better than those created by the Alien Screamer and the Noise Toaster. Yet, the Noise Toaster seems to have more synth features though.
All, in all I think the Synth Experimenter probably would be a good launching point.
Thanx for the info on the LFO's though. It turns out it is more capable than I thought.
Geo
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Skrog Productions
Joined: Jan 07, 2009 Posts: 1196 Location: Scottish Borders
Audio files: 155
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Posted: Sun Jun 02, 2013 4:40 am Post subject:
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i had a quick look at the noise toaster and screamer and wsg , they are powered from +9v only , introducing a bi-polar supplied lfo to modulate those synths would at best just receive the top half of the lfo wave cycle and in worst case feed a -v lfo wave cycle and upset those circuit designs . fizzz .
Looking at the experimenter pcb , it runs on 2 x 9v batteries / or a bi-polar 12v supply , if you were to sort your self with a good 1.5A bi-polar supply (mfos do a diy one) that would provide ample power for sequencer and clocking / division / strange modules later on .
The simple projects are fun to do but i think you want onto the proper +/- supply standard sooner than later .
have fun deciding your system , and as everyone here will agree and all been through it , read all the projects info again and again before soldering and panel designing , any questions along the way someone will be around to advise if they can
Welcome to the hermit world of diy modular , say goodbye to daylight and social contact now
Dave. |
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jukingeo
Joined: Oct 24, 2007 Posts: 166 Location: The dark side of the moon
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Posted: Sun Jun 02, 2013 7:44 am Post subject:
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Hello Dave, Good morning!
Skrog Productions wrote: | i had a quick look at the noise toaster and screamer and wsg , they are powered from +9v only , introducing a bi-polar supplied lfo to modulate those synths would at best just receive the top half of the lfo wave cycle and in worst case feed a -v lfo wave cycle and upset those circuit designs . fizzz . |
Yes, a while back I did notice that there is a great difference in power supplies. That was something that did slip my mind coming back here. Mostly those pieces were meant to be stand alone. With some having a built in speaker, they were more or less meant to be portable to make sounds 'on the go'. Changing out one battery when it dies is more cost effective than a dual battery power supply which would need to have the batteries replaced 2 at a time. While I DO like the portability idea, the thing is it would be something I wouldn't do that often. For one, I know I would be toting around only 'part' of my rig and probably would 'miss' not having module 'x' or module 'y' with me. So, overall, given the nature of what I would like to do mostly dictates a set up that will mainly stay in one location.
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Looking at the experimenter pcb , it runs on 2 x 9v batteries / or a bi-polar 12v supply , if you were to sort your self with a good 1.5A bi-polar supply (mfos do a diy one) that would provide ample power for sequencer and clocking / division / strange modules later on . |
Yes. In addition, I noticed that MFOS has a PCB combo pack that has the Experimenter board, power supply board, AND the Sample And Hold board sold all together. So I would most likely go that route.
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The simple projects are fun to do but i think you want onto the proper +/- supply standard sooner than later . |
Correct. I would rather run the unit mostly on a line based power supply rather than having to worry about replacing batteries all the time. In addition, once I would start adding things to the rig, the added current draws would add up to require the replacement of batteries more often and replacing 2 9v batteries at a time is certainly far from cost effective.
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have fun deciding your system , and as everyone here will agree and all been through it , read all the projects info again and again before soldering and panel designing , any questions along the way someone will be around to advise if they can |
Well, I will say that I am still on the fence of what I would like to do. I have known about MFOS since 2006 when only the Sound Lab, WSG and Modulars were around. Yes, THAT long. Ray has added quite a bit since then and naturally that has complicated the decision making process for me.
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Welcome to the hermit world of diy modular , say goodbye to daylight and social contact now |
Well, being somewhat of a recluse that sunburns WAY too easily already, that isn't too much of a problem .
One problem lies in money, though I know these synth projects can run into hundreds or even thousands of $ very quickly. So the choices I make need to be good - wise ones.
Thank you for the reminder on the power supply differences. It certainly helps in that I can scratch any of those smaller projects off my list. While I know a sequencer (or S&H) could be added to those smaller 'noise boxes'...the issue would come into play later on when I would start to add modules. However, after thinking things through the past few nights, I somewhat made a decision to build something around the Synth Experimenter board mainly because that board is already patched out, and yes, since it uses the split power supply already, that is one less thing to worry about.
Thanx,
Geo |
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Skrog Productions
Joined: Jan 07, 2009 Posts: 1196 Location: Scottish Borders
Audio files: 155
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Skrog Productions
Joined: Jan 07, 2009 Posts: 1196 Location: Scottish Borders
Audio files: 155
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Posted: Sun Jun 02, 2013 8:41 am Post subject:
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the plywood for the modular was off cuts in a constuction site skip , the 3mm thick 100mm W by 250mm H aluminium i got as off cuts from a local highway sign depot , they can cut to size with the big hydraulic slicer, the panel stickers i designed in an old copy of Corel draw software saved the designs as bitmaps and took to a sign printing shop when i get the blue toner lazered onto white adhesive vinyl , i'm going to do a pictorial on my new synth thread there will be pics in a month or two or three
Dave. |
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jukingeo
Joined: Oct 24, 2007 Posts: 166 Location: The dark side of the moon
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Posted: Sun Jun 02, 2013 9:24 am Post subject:
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Oh Dave. OMG! That's quite the modular you got there. I would say all that would be equal too, if not surpassing the ARP 2500. Wow, you certainly DID get bitten by the synth bug, huh?
Skrog Productions wrote: | i decided to have a look at my component supplier (rapid uk) at my account page and over 7 years building my system i have spent £4300 on components and hand tools & solder , it is much more affordable over a period of time than buying modules from shops all in one go .
Dave.
The pic was too big in another post , i reduced the same pic of my mostly mfos diy system. |
Yeah, my wife certainly would have my head on a silver platter if I did just HALF of what you have. But I know, it can be addictive. Just now I was listening to some samples on the MFOS site on the Phase Shifter. The pseudo stereo effects that thing creates is fantastic. Clearly something I would want in a modular.
But, man I have to hand it to you, that is SOME rig you have there. Sheesh, I wonder how many VCO's & LFOs you got there!
Anyway, thanx for sharing. That certainly was my jaw dropping moment of the day!
Skrog Productions wrote: | the plywood for the modular was off cuts in a constuction site skip , the 3mm thick 100mm W by 250mm H aluminium i got as off cuts from a local highway sign depot , they can cut to size with the big hydraulic slicer, the panel stickers i designed in an old copy of Corel draw software saved the designs as bitmaps and took to a sign printing shop when i get the blue toner lazered onto white adhesive vinyl , i'm going to do a pictorial on my new synth thread there will be pics in a month or two or three
Dave. |
LOL, I was sitting here gawking over that picture you sent and didn't realize there was another post. Well, in terms of building, I do want to keep the cutting down to a minimum. There was a great idea with using shelving material on the MFOS site and then it hit me. Next to me is a rather large book case that is about 2 and half feet wide. Adjusting the shelves a certain way WOULD yield a nice row where I could put a frame that holds the synth modules.
So then remains the question of the face plates. I DO have Corel Draw myself, though. I am also checking out a Corel alternative in Linux called Inkscape. Unfortunately I don't live close to a metal sign shop .
I am assuming you have (or have access to) a drill press as well, right? That is something that always haunts me when trying to make any kind of project where holes have to be lined up. I don't have drill press, nor do I have room for one.
Thanx,
Geo |
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elmegil
Joined: Mar 20, 2012 Posts: 2177 Location: Chicago
Audio files: 16
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Posted: Sun Jun 02, 2013 6:14 pm Post subject:
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I got started last March (2012), and that's exactly what I did--I put a frame on a bookshelf in my office. 13 wide and then I put two horizontal 2U slots up top.
Of course I have since far outgrown that, and I have a repurposed entire bookshelf in the basement with 60 wide of 5U and quite a lot more on the back wired and spaced to fit Euro. Only two Euro modules though, not planning for that to grow a lot....but once upon a time I said never at all, so who knows. |
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jukingeo
Joined: Oct 24, 2007 Posts: 166 Location: The dark side of the moon
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Posted: Sun Jun 02, 2013 8:09 pm Post subject:
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elmegil wrote: | I got started last March (2012), and that's exactly what I did--I put a frame on a bookshelf in my office. 13 wide and then I put two horizontal 2U slots up top.
Of course I have since far outgrown that, and I have a repurposed entire bookshelf in the basement with 60 wide of 5U and quite a lot more on the back wired and spaced to fit Euro. Only two Euro modules though, not planning for that to grow a lot....but once upon a time I said never at all, so who knows. |
Well, looks like I am not the only one with that idea . I am not good when it comes to carpentry work and I certainly wouldn't want to build something from scratch. So when I saw that one approach was using shelving material, I just ended up looking next to me and then it hit. If I could find a home for some of the books one row that certainly would be enough of a start.
I just have to go through everything in regards to making up panels which is another weak area for me.
Geo |
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elmegil
Joined: Mar 20, 2012 Posts: 2177 Location: Chicago
Audio files: 16
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Posted: Sun Jun 02, 2013 9:13 pm Post subject:
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I started out using 1/8" MDF to make panels, with aluminum tape (stuff they use for HVAC) for grounding. Then I found Metal Supermarkets and have been able to get reasonably priced, cut to size blank aluminum panels. Now, I have a drill press (a bench top, not a full sized one), and I think without that I'd probably go crazy, but the whole workflow works well for me. I design panels in Photoshop, invert them (so it's black with white lines & text), print them to quality sticker paper, put them down and clear coat them, and so far so good. I have had a couple recent trades bring in some 'real' panels but I'm still 90% hand made. |
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jukingeo
Joined: Oct 24, 2007 Posts: 166 Location: The dark side of the moon
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Posted: Wed Jun 05, 2013 4:16 pm Post subject:
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elmegil wrote: | I started out using 1/8" MDF to make panels, with aluminum tape (stuff they use for HVAC) for grounding. Then I found Metal Supermarkets and have been able to get reasonably priced, cut to size blank aluminum panels. Now, I have a drill press (a bench top, not a full sized one), and I think without that I'd probably go crazy, but the whole workflow works well for me. I design panels in Photoshop, invert them (so it's black with white lines & text), print them to quality sticker paper, put them down and clear coat them, and so far so good. I have had a couple recent trades bring in some 'real' panels but I'm still 90% hand made. |
I know that there are those here that have good results without using a drill press, but I do know how much easier (and more accurate) the job would be with a drill press.
Space, even for a bench one, is as a premium since I live in an apartment. Then there is the cost factor as well. Yeah, there are the cheapos, but you get what you pay for and I wouldn't want to skimp a drill press.
The aluminium tape for grounding idea is a good one. I have to keep that in mind.
Geo |
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jukingeo
Joined: Oct 24, 2007 Posts: 166 Location: The dark side of the moon
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Posted: Sun Dec 08, 2013 8:51 am Post subject:
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Skrog Productions wrote: | Hi , yes the vc-lfo goes from 1 cycle 2mins to doggy distressing high pitch .
it is inevitable you will be sucked in by modular lust , none of us have escaped so far , if you are happy making a +12v / -12v power supply then they will be a great start to your very own home made system.
If you are fairly new to diy synth i'd recommend the easier noise toaster or wsg or experimenter first to get the hang of things.
Dave. |
I know this is one of my older posts, but I was thinking about this thread as to adding double duty VC-LFO's that I could use also as VCO's.
Dave according to what you wrote you mentioned that the VC-LFO can go to 'doggy distressing high pitch'. I am assuming that some modification would be needed for it to do that, correct? As it is I was looking up the circuit description for the VC-LFO and it says it can do up to about 600hz. That certainly isn't doggy distressingly high. However, I am not sure if you meant that after doing a switch modification on the VC-LFO. I am assuming that you need to switch out a capacitor, correct? If so, I am curious to the construction of the circuit.
Thank You,
Geo |
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Skrog Productions
Joined: Jan 07, 2009 Posts: 1196 Location: Scottish Borders
Audio files: 155
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Posted: Mon Dec 09, 2013 10:31 am Post subject:
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It depends what breed of dog is nearby , i have an oscilliscope & a frequency meter but i don't own a hound.
Can i suggest a plan of action ..........
Build the experimenter pcb first , get it running well , Then , when all the bought MFOS stuff is singing and dancing happily, think about modifications.
In an ideal world doing all the mods you can think of at the begining could save a lot of time & re-ordering, but , as i have experienced things rarely go to plan , it would be really hard to help you out with de-bugging if it was not knowen if the main pcb (experimenter) wiring , grounding , orientations, was tip top before the mods.
Good luck with starting the soldering
Dave. |
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jukingeo
Joined: Oct 24, 2007 Posts: 166 Location: The dark side of the moon
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Posted: Mon Dec 09, 2013 4:08 pm Post subject:
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Hello Dave,
Skrog Productions wrote: | It depends what breed of dog is nearby , i have an oscilliscope & a frequency meter but i don't own a hound. |
Nope, no hound here either. We have kitties though.
Quote: | Can i suggest a plan of action ..........
Build the experimenter pcb first , get it running well , Then , when all the bought MFOS stuff is singing and dancing happily, think about modifications. |
Mainly the reason I mentioned the mods was because I needed to know what controls I would need. However, if there is a way to make up a temporary control panel then once things are running I can add anything else I want.
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In an ideal world doing all the mods you can think of at the begining could save a lot of time & re-ordering, but , as i have experienced things rarely go to plan , it would be really hard to help you out with de-bugging if it was not knowen if the main pcb (experimenter) wiring , grounding , orientations, was tip top before the mods. |
Gotcha
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Good luck with starting the soldering |
Actually I have to start ordering parts first.
Geo |
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