Circuitbenders Forum
Circuitbenders Forum => Circuitbending discussion => Synths & Samplers => Topic started by: kriminal on August 02, 2010, 07:44:11 PM
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anyone interested in doing mods for this?
specifically something like 'monodular' seen here
http://korgc383.tempdomainname.com/Product/Dance/monotron/welove/#a2 (http://korgc383.tempdomainname.com/Product/Dance/monotron/welove/#a2)
http://houshu.at.webry.info/ (http://houshu.at.webry.info/)
or the Monotron+ (with MIDI)
http://beatnic.jp/monotron/index.html (http://beatnic.jp/monotron/index.html)
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anyone? i thought you guys would be all over this synth....
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i really like the look of those bends and that..
just up my street... but unfourtunatly its a bit advanced for me at the moment i just tinker with kids toys and the occasionall keybord...
if you have one and arnt to fussed about deading it just unscrew and poke around at the circuits...my betting is you soon find glitches and pitch mods etc....
see what u kan do triall and error styley!
=)
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apparently...." if you open up the case you'll see on the PCB that the CV gate bend point is clearly labeled, so theoretically it should be fairly straightforward to retrofit MIDI or control it via CV"
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thanks for the links and have you got a monotron Kriminal?
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i have, bought one last month. When the local shop gets some back in stock im gonna get another one, hopefully to get modded (but not by me, thats something i cant even think about trying :D )
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a friend over in the states just added midi on his sounds ok. Have to say was a bit bored after twiddling it for 10 mins, and i find the interface quite laughable it is like it has been made for a child, judging by the size of the keys and pots. Think they could have gone to town on the construction and put lots of leds on and made the pots better. But at least they bothered good to see one of the big companies still keeping their ear to the ground. The filter is probably the best thing about it and has an input so is useful, sure some good mods will come out to haven't had time to try yet. I think the gakken looks better and is actually better on some fronts though that has big draw backs also but at least it has an envelope.
edit: i tried to add cv/gate last night, cv seems to work alright, goes strange when you add the gate signal, would be interested to hear others experiments. No low notes when gate is added, didn't have much time to fanny about with it, have to say the build quality is very flimsy and it is not much of a pleasure to work on because it is too small. Pitch, gate and cutoff are marked on pcb.
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Pitch, gate and cutoff are marked on pcb.
Almost as if they knew this would be a target for modding and planned for it in advance. :-\
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i reckon they will wait and see what mods people come up with and then release better modules later maybe pinch a few ideas on the way. I'm pretty sure they want people to mod em, but its like they are trying to be uber cool by making it so small but it just makes it really difficult to fit anything in and use it. But the back kinda flips up so you can access the back of the circuit where the pcb markings are so you can access it which is good as the battery compartment is really annoying and the components on the other side are microscopic surface mount cant imagine trying to put anything on there. I'm sounding kinda negative i know, but it does have something, the sound can be quite tough and solid.
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these look really cool! not a bad price either, with all the features! actually, i feel lik i am not far from being able to make one, but i would still like to have one of these!
to bend or not to bend, that is the question...does it mean you should, just because you can?
these things look pretty cool unbent. perhaps making more synth filters to add to it in a breakout box? make it so you can plug the breakout box in...
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to bend or not to bend, that is the question...does it mean you should, just because you can?
my answer to that is yeah bend the hell out off it ;) without looking at what everyone else has done first see what u can get out off it ;D (i find i just end up imitating other peoples ideas and NOT innovating my own if i see some else's bends first)
anyway I've got some birthday money and I'm gunner get one and see what can be done - happing bending
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What's inside one of these? Are they worth getting?
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tiny circuit and components, mine is lying in a heap with some mods attached, i couldn't be bothered trying to get the cv/gate to work properly (no low notes). They do work but i got side tracked and never finished it. You need tiny fingers to use it! kinda over rated but there is something about it. Poor build quality though, horrible little pots and the ribbon controller is laughable its so small. I could take a pic if you want Gordon mine is already open.
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tiny circuit and components, mine is lying in a heap with some mods attached, i couldn't be bothered trying to get the cv/gate to work properly (no low notes). They do work but i got side tracked and never finished it. You need tiny fingers to use it! kinda over rated but there is something about it. Poor build quality though, horrible little pots and the ribbon controller is laughable its so small. I could take a pic if you want Gordon mine is already open.
Thanks for that ive changed my mind i have hands like shovels so the monotron is not for me i quess
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i think you would need dolls hands to use the ribbon controller ;) i've had a think and Gordon if you want i'll send you my monotron if you wanna have a look at it and if you can work out whats goin on with it and sort out my mods, and you can have a look and decide if you want one. They have a powerful filter. I just stay in Edinburgh so it's just down the road you got my email give me a shout if you want and i can send it somewhere for you.
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to me, instead of bending what is already there, adding a few more filters would be the thing to do! a resonance filter so you can play the beginning of tom sawyer from rush....BBBZZZZZZZZEEWWWW! lmbo! an envelope filter would be tasty too...
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I've actually found some pics online of the inside - http://www.timstinchcombe.co.uk/synth/korg.html (http://www.timstinchcombe.co.uk/synth/korg.html) - here.
From the description it sounds like it's a similar thing to a Gakken SX-150 with a Korg35-type filter similar to early MS-series synths. I bet you could build a better one with things you find at home ;-)
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i think most of us probably are building something better, Korg better pull their finger out before we are showing them the way forward lol
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Well, liinked on that page is a circuit that approximates the Korg35 filter. It's not a very good filter, with pretty poor frequency tracking and a fairly variable resonance characteristic as you sweep the cutoff. The distinctive sound is caused by the input voltage affecting the biasing of the two transistors used as the voltage-control element in the filter network, which basically modulates the cutoff with the input signal. The filter VCO mod on CEM3394 does the same job. The Gakken SX-150 filter is broadly similar, it's worth noting. I think it's 12dB/octave where the Korg one uses two filter circuits in series to give 24dB/octave response.
Maybe something like an Arduino could be used to do the oscillator and envelopes, and then an analogue VCF/VCA circuit to process the sound...
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could someone give me the lowdown on ribbon controllers? i know that the korg triton has it. are they hard to make?
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i had a look at making a ribbon controller but my basic attempts have all failed but i have saved some web pages
http://www.paia.com/ProdArticles/dual-ribbon-howto.htm (http://www.paia.com/ProdArticles/dual-ribbon-howto.htm)
http://www.electronicpeasant.com/projects/ribbon/controller.html (http://www.electronicpeasant.com/projects/ribbon/controller.html)
post up something if you manage to make one work
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Heres some mods for the Monotron with schematics and video documentation: http://www.dinsync.info/2010/06/how-to-modify-korg-monotron.html (http://www.dinsync.info/2010/06/how-to-modify-korg-monotron.html)
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the MUSICIAN'S FRIEND description has "filter any external source using the audio jack input"!!! i must have one!!!
i want to learn to make one too...i have some bucks in paypal...buy one of these or component order...hmmm...i am low on potentiometers and some things i really need.
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You can build a nice external filter based on the Steiner Synthacon VCF quickly and easily. There's even a version from a guitar synthesizer that will run off 9V.
Interestingly, it has high-, low- and bandpass *inputs* rather than outputs, so you can use it to mix different sounds and sweep the filter across to do a bizarre crossfade. Have a listen to the recording I posted in the AVR homebrew hybrid synth thread.
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i'll look that up, thanks!
i still haven't built a vcf. i want to start with the simplest one first though. as few components, etc. and kind of build my way up.
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this vcf is pretty simple with low or bandpass output
http://www.magicmess.co.uk/electronics/12dbfilter.php (http://www.magicmess.co.uk/electronics/12dbfilter.php)
and this oun uses only 6V :o
http://www.magicmess.co.uk/electronics/6vfilter.php (http://www.magicmess.co.uk/electronics/6vfilter.php)
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I've had great fun sending my bent sounds through the Monotrons filter - recommended! :)
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an easy, handy mod....build a box around one of these, with a footswitch, and phone jacks so it will resemble a stomp box...add it to your pedal board!
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i got a monotron for my birthday its cool it could do with an lfo trigger button though, work van studio is growing, i can wait to road test it against my ms20 but the builders out the back of my studio have put the building in danger and i cant go in there hat to take all of my gear and put it in the conservatory i am going to kill them seriously whre casn i get a crossbow >:(
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having played woth the monotron i can see it needs never gonna be an ms10/20 without the modulation possibilities that said i can see a few improvements that would make it cooler, the lfo retriggers when you press the ribbon controller which is great but you also get the osc at the same time so the osc needs a cut switch or vol control also an input to retrigger the lfo say from a drum machine trigger out would be good , a proper output would be good as would be cv cutoff control and gate in , i cant really see the point of adding pitch cv as its a pretty ordinary sounding osc without the modulation possibilities of the ms20 any ideas?
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here is the schematic of the monotron i have marked the points where i think i could add a volume control or mute switch and also where i think i could put an input for to retrigger the LFO from a drum machine trig out can someone please tell me if im barking up the right tree with this ? also would i have to trigger it via a transistor or would the 5v pulse alone do the trick? cheers ciaran
(http://i1139.photobucket.com/albums/n551/ciaranbyrne606/MOnotron.jpg)
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Depends what you expect it to do. You could replace R35 with a 4.7k pot and use that as an oscillator level control, with the wiper going to C14.
The LFO reset will probably work with a 5V pulse injected where you have indicated.
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Depends what you expect it to do. You could replace R35 with a 4.7k pot and use that as an oscillator level control, with the wiper going to C14.
The LFO reset will probably work with a 5V pulse injected where you have indicated.
cheers gordon 8), i would just like to be able to mute or control the volume down to zero of the internal osc as it is mixed with the external input , in fact it would be cooler if it just cut the osc when i put the jack in, so i can use the ribbon controller or a drum machine trigger to reset the lfo without hearing the internal oscillator so i can do rythmic lfo stuff say on a drum loop for instance also i would like to add a proper output pre the headphone amp as its crap can i just add a socket after the VR2a volume pot to achive this? thanks for your help
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Would it be possible to make a wave changing switch in there for the vco.. I see some different ones.
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OMG i am going to have fun with one of these when i get some money saved (hopefully early 2011...).
as soon as i can, i am going to invest in some "cheap" synths, like monotron, stylophone, etc and immediately take them apart! ;-)
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Looks like there's only a sawtooth output. Make a comparator to turn it into a squarewave. Add some sine LFO to the comparator setpoint to get PWM.
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so, has anybody here bought one of these and bent one yet?
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i GOT ONE! ;-)
yesterday, i frantically looked for 2 aaa batteries and could find only 2. "this will not do anything but make faint sounds...these must be dying...". i was hoping anyway.
today, after getting a little sleep, i shook the box and 2 NEW batteries fall out. YES! so, i installed them and it worked!
so, i even though i am still exploring this product, and cannot give it a FULL review, i will insert my first impressions here.
this thing is TINY! i mean, about the size of an altoids can! smaller than a stylophone! it is plastic, and i would be careful with the pots. they seem durable (and will take knobs, so you can customize it!) but, are small, plastic and soldered to the pcb...
the sound quality of this thing is amazing! i am speaking about through the tiny internal speaker. i have not tried the 1.8" jacks yet.
the filter is just magical. bandpass i presume? the PEAK control seems to be a lot like RESONANCE!
there is a lot in this tiny package. feature rick and sound quality are amazing! but, it just seems for $60, one could get a little better quality.
mods? maybe build it in a bigger box, with actual keys, and wire 1/4" phone jacks ? adapting down is just absurd if you dont really have to! also, building this into a bigger box, and making the filter as part of a patch bay would so so cool! ;-)
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i just hooked up a stylophone to the input...the vcf and lfo effect it nicely! i love this thing...more stuff i need to learn to build now! ;-)
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http://www.synthtopia.com/content/2010/11/05/korg-publishes-monotron-schematic/ (http://www.synthtopia.com/content/2010/11/05/korg-publishes-monotron-schematic/)
You'll probably find that interesting. Stick it alongside the Gakken SX-150 circuit and play spot-the-difference!
It's definitely not an MS20 filter clone.
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hmmm...so the korg clone is not true to their claim, printed directly on the box..."add the legendary +ms-20 filter..."
it's still killer, noisey, beautiful!
i wonder if the internal speaker was removed if the sound would change/improve?
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i take it nobody has modded one of these yet?
i connected my stylophone to it and the monotron filters that nicely!
one thing i can't stand is, the 2 jacks are so close together, if i adapt a cable down, i cannot connect both....grrr!
i wonder why they don't make a bigger and more deluxe version, all analog?! (meaning no midi, no modeling, no usb!)
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If you look at the output stage there's an odd thing that looks like the speaker amp has a bit more bass cut than the line/headphone output. Oh, and it uses a four-way 3.5mm jack with the second ring being used to mute the speaker!
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i havent taken mine apart yet. i have been checking out some photos on different sites, and the circuit board is like a colouring book!
on the solder side, it is even labeled, "lfo, vco..." etc! the resistors are labeled, etc. they obviously WANT people to mod these...the first commercial product MEANT for circuit benders perhaps? ;-)
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A lot of older Korg analogues have the sections of the board separated out with dotted lines and labelled as LFO, VCF etc. The Korg Micro preset i worked on recently certainly had, and that was from about 1978!
It certainly makes working on these things a whole lot easier.
If you look at the output stage there's an odd thing that looks like the speaker amp has a bit more bass cut than the line/headphone output.
presumably so the speaker isn't trying to reproduce frequencies it can't possibly manage?
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yeah, the bass hardly comes through the tiny speaker...but, who cares! this thing sounds HUGE when plugged into an amp or mixer!
i've been filtering other things, and it sounds sweet! i have a zoom drum machine, and i filtered a drum track. it sounded nice and dirty! especially when the resonance cuts through!
the stylophone sounds good through it too! i am seriously thinking of building the stylophone and monotron into one box with real keys!
even if not a recent developement, it was nice of korg to label their pcbs!
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Did you notice how easy the filter would be to clone? Pretty easy...
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yeah, lowpass filters only have a few components...
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heres a pic of my modded monotron with a bicycle led blinker used to
change pitch
(http://img269.imageshack.us/img269/2897/0608110250.jpg)
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unless i am mistaken, the major difference between the monotron and the gakken is the gakken has a stylus and plate, the monotron has the ribbon/ the gakken sh0uld be even easier than a stylophone to add a real keyboard to, the monotron, not so sure...the gakken (like a stylophone), i assume the stylus is common, and the plate is positive, right? if that is all there is to it, a keyboard would be easy to apply. but how do i do this to the ribbon? i tried a resistor ladder on an oscillator i built and i could not get the notes in the right pitch...