Kits kits kits

The kits are currently unavailable but we will have some news about then around the end of feb hopefully.

Thats right, kits! If you haven't noticed over at muffwiggler here and here. We have been putting together partial kits for the VCF303 and MODSEQ. By partial we mean we only supply the difficult to find parts and the easy off the shelf stuff you find yourself. This keeps costs down all round and if you are able to solder and have a eurorack system these offer great value for money.

Here's the price list below.

VCF303 partial kit 780 SEK including VAT (countries outside the EU can deduct 20%) 
OUT OF STOCK

MODSEQ partial kit 412 SEK including VAT (countries outside the EU can deduct 20%)


There's a short waiting list so if you would like to be added just drop a line to info@dinsync.info and we'll let you know when they are available.

Build documentation for these projects are here

VCF303 PKIT BUILD
MODSEQ PKIT BUILD

please note these are reasonably large downloads.

ModSeq kits are here! (SOLD OUT)

NOTE: if you are looking for the partial kits documentation you can download it HERE

Please note, we only have a limited supply of these and they are only available direct from us here at the blog.
Fancy a bit of DIY? if so we probably have the perfect little project for you. An affordable roto-sequencer you can build yourself.

We've written a manual that should enable anyone with basic soldering skills and some tools to be able to build one with ease. It is quite an easy project, but in case you are in doubt have a look at the build manual RIGHT-CLICK-SAVE it'll show you the kinds of tools you'll need for the kit and what's involved.

If you don't know what the ModSeq is, take a quick look at these videos








These are now sold out, sorry!

A close up look at the new Korg MS-20 Mini

I got fed up with the waiting times and managed to pick up an MS-20 Mini from Japan, so I figured I'd run through some of the things that haven't yet been mentioned in previous videos. Also I show how to make a cheap V-Trig to S-trig converter so that you can use normal gates to trigger the Mini. Finally a trick to use a standard cv/gate sequencer with the Mini with something unexpected as the converter!

Overall I'm very pleased with the unit, the build isn't as solid as the original but the keybed is better for sure. Still at this price there's really nothing to grumble about.

So here's the pics of the partial teardown I did, doesn't seem to be any magic points marked on the silkscreen like on the monotron/tribe but it's always possible there is something on the component side, i'll let someone else discover that ;)

Monotribe CV/Gate Jacks

Korg recently released an update to the monotribe OS and there has been a lot of chatter on the Muffwiggler forum (click the link for details on where to get the OS, how to install it and enable the CV/Gate)

The main drawback is that in order to get this to work you need a 4 pin mini jack. I dont have any of those around so I figured I'd just add some jacks.

Here's a few pics of the install and solder points, and a quick video demo of the monotribe being driven by a ModSeq (sorry about the camera audio).

Some points to note, first I wired up also for CV/Gate output, this is not yet fully working, I'm hoping it will in the future so I figured I'd wire it up while i was there. The Gate out does work at least (its just the sync out really)

It also seems that the sync in jack is switching, so that if there isn't a jack inserted to sync in then you wont be able to advance the sequencer with the gate in (like you could with the cable) The work around for this is that you can use the gate out (or the sync out jack) to clock your external seq then just mult that to an envelope and send it all back to the monotribe cv/gate ins. I may check this out later to see if I can add a switch.

Anyway, big ups to the muffwigglers on this one, cheers guys!

4MS SCM tap tempo mod

This simple mod adds a great tap tempo functionality to the 4MS shuffling clock multiplier.

you need a push button
1N914 diode (i didnt have any in my parts box and used a 1n4148 which works fine also)
1k resistor (you dont actually need this but its not a bad idea)

first get rid of the slip jack

I had to whittle the hole out a little to fit the button, be careful here as the metal is very soft (you can do this by hand gently with a flathead screwdriver)

the pics show how to wire it up
the blue wire has a 1k resistor in series,
the yellow wire has the diode in series with the band facing the board
(away from the switch)

basically it takes the power from the output pin of the 5v regulator via a 1k resistor to one side of the switch. The other side of the switch has the extra diode and is soldered to the cathode (the side with the band) of the diode on the pcb that comes from the input jack.

EDIT: I should point out that this may not be the same pcb revision as the current ones selling (it looks different in the user manual) so if in doubt, dont do it ;-)

Using Korg SyncKontrol (iOS) as a modular clock

Here's how to use the free iOS app SyncKontrol from Korg with your modular synth.

At the very least you will need to amplify the output and ideally use something like a Maths to control the pulsewidth of the clock, though it will work without one if amplified.

Here's a schematic for a DIY noninverting amplifier.



Download the Korg SyncKontrol for free here

Synovatron DIY Eurorack prototyping kit - Follow Up

As promised here's the follow up video to the Synovatron DIY kit post.

I used the kit to make a simple polarizing CV mixer. To make this all you need is the Synovatron kit, seven 100k resistors, a dual opamp (tl072/tl082/lm358 etc) and an spst switch.

The inputs are unbuffered but you could simply add a couple more opamps to buffer them if you wish.



click the picture to download a PDF of the schematic.

Buy Synovatron DIY Kits on ebay

Visit the Synovatron blog

Ok so this is the last post of the year, hope you have a great 2011

Cheers

Paul

Synovatron DIY Eurorack prototyping kit

Hope you are all having a nice holiday. Here's a quick overview of the DIY kit#1 I just received for evaluation from Tony at Synovatron.

All in all its a great little tool for those of you that like to DIY your modulars, I'll be doing a follow up video at some point so keep your eyes on the blog to see what I make with this kit.

Here's the details of what you get with the kit,

Eurorack Modular Synth Prototyping Kit 1

This is one of the new Eurorack standard modular synth prototyping kits for synth constructors and enthusiasts; these kits will enable you to make neat prototype or one-off projects that accomodate bracketed pots, PCB mounted jacks, switches and LEDS so that they can be easily mounted to a module front panel. The idea is that you build your designs on the prototyping boards supplied and get the front panel manufactured separately, either by yourself, or by a company such as Schaeffer (A Schaeffer template file can be provided that you can use directly or can modify as you require). The PCB header and ribbon cable assembly is compatible with Doepfer power bus connectors and supports CV, Gate and +5V connections too.

This kit comprises the following components:-

* 1 x DIY1 prototyping circuit board (104.3mm x 47mm x 1.6mm) with dedicated pot, bracket, header and capacitor locations, power rail bussing and a 0.1" matrix breadboarding area
* 5 x control pots (50k linear supplied as standard but 10k linear, 100k linear, 1M logarithmic or a mixture are available upon request - ask about availability)
* 5 x pot mounting brackets
* 2 x 100nF decoupling capacitors
* 2 x 16-pin headers

* 1 x DIY2 prototyping circuit board (100mm x 20.3mm x 1.6mm) with dedicated jack socket and/or toggle switch locations and a 0.1" matrix breadboarding area
* 5 x 3.5mm jack sockets

* 1 x DIY1 to DIY2 linking ribbon cable assembly (16-pin IDC socket to 16-pin IDC transition, 75mm long)
* 1 x standard ribbon cable assembly (200mm long)

Buy Synovatron DIY Kits on ebay

Visit the Synovatron blog

Roland SH-101 Modifications

You can wire the LFO outputs direct from the rear of the LFO selection knob at these points. Wire the tip of the jack to the point in question and wire the sleeve of the jack to a convienient ground.



You can wire the oscillator outputs direct from the rear of the source mixer faders at these points. Wire the tip of the jack to the point in question and wire the sleeve of the jack to a convienient ground, with the VCF cutoff cv, add a 100k resistor in line to the tip of the jack. To wire up the triange output, simply wire the tip of the jack to pin 10 on the CEM3340 ic. (this is done exactly the same as it is for the MC202 vesrion of this mod, details here)



work in progress...



all done.

6th September UPDATE



I added this picture of my ground wire (red wire center of the pic.) As you can see theres a nice little ground symbol marked on the control board. I found this to be the best place to take ground from for this mod. Also your connection wires should be shielded wire, leave the ground floating at the pcb end (you'll see mine have some heat shrink tubing to insulate the shield from touching the board and connect the shield at the jack end, this will create nice little rf jackets for your "live" wires. If you don't use shielded wire you'll end up with some bleed through from the circuits.

DIY Eurorack Modules

I hope you are having a nice summer holiday, anyway in my spare time I've made a few modules for my Eurorack. The inspiration for these came from a Quad Slew design from navs modular lab blog. In that article I came across a link to a DIY page by Doepfer which I hadn't seen before. There's plenty of simple projects there and so I set to work and ended up building a Quad Slew, a Dual Inverter, a CV Amplifier, an Audio Mixer and an expansion port for my A-137-2 Wave Multiplier II. And here's the result.

There's some discussion about the Quad Slew over on the Muff Wigglers Forum

Here's some pictures I took during the build.



The blind panels after drilling



All the hardware mounted (but not yet wired)



Wiring up the Mixer.



Side view of the Mixer, as you can see I glued the opamp to the back of a pot.



Wiring up the Quad Slew.



Wiring up the Dual Inverter / CV Amplifier.



Side view of the Dual Inverter / CV Amplifier, again the opamp is glued to a pot.



Here's what my modular looks like now with the new modules labeled and installed.

How to modify a Korg Monotron

So here's how to modify Korg's new Monotron analog ribbon synthesizer. Perhaps this is the first document of Monotron mods in Europe since it still hasn't been released here.

It's actually a very easy machine to modify because for whatever reason Korg decided to label all the interesting points on the bottom side of the PCB. This may well have been for testing units at the factory/service centers. Perhaps though it could have been that the designers anticipated this little machine would be hacked, much like the Gakken which pretty obviously inspired this piece. Incidentally in the magazine that comes with the Gakken there's a picture of them showing it to Korg, that was in 2008, go figure.

Modification wise everything is simple enough except for the gate. Unfortunately the gate point affects the pitch somewhat. There's a few solutions, the first of which is to use a single pitch cv line into the gate socket. This will work but you wont be able to get really low notes which is less than useful.

After a little research I came across an idea to use a dtc114 transistor to trigger the gate (soldered at a different point). I tried this but didn't have much success. Also that method will result in the LFO not re-triggering which is bad since the LFO is the closest thing to an envelope on the machine.

By far the simplest solution is to use something like Silent Way by Expert Sleepers (see my previous video on this software) or Volta by Motu. After calibration there's no issues whatsoever and the monotron tracks over 5 octaves nicely.

Using an adjustable dc power supply is a good alternative to the batteries and is also useful in getting the Monotron to a decent tuning range, just don't dial in more than 3 volts. I built my power supply based on this schematic

If you intend to use both battery power and dc power you should include some diodes in your design.

And lets not forget the filter, the side of the packaging says "the legendary MS-20 filter" while this is true design wise it would probably be more accurate to say the MS-10 filter since it's only low pass and the MS-20 has low and high pass filters. How does the filter sound? actually very good! I've repaired some MS units and the Monotron really does have some DNA from the MS series, even down to the small noise hiss when the resonance is high but not yet self oscillating.

A couple of things I noticed about the filter input, if you drive the input signal too hard the resonance almost disappears, so be sure not to overdrive it too much if you want the full character of the filter. Also the input jack is stereo which means if you use a Y cable you can run two signals into the filter comfortably. I tested to see if the left side input leaked to the right input and it doesn't at all, which means it really is a true stereo input to the filter which is very nice.

As for the output, even though it's a mono output via a stereo jack the manual states that you shouldn't use a mono jack on the stereo output, so it's probably best to use a stereo jack plug but leaving the ring floating to get a mono signal into your daw/mixer. The output is a little noisy due to the fact that its really a headphone out and the output level is a little low so you will probably want to use a noise gate to remove the noise floor when it's not playing. (this is the same with the Gakken)

That's about it, here's the diagrams for modding, as you can see it's very simple indeed and should be no problem for anyone with soldering skills.

The Monotron should be available to buy in Europe from around the 30th of June for around 50-60 euros.

Gakken SX-150 Modifications

Here's what's got to be one of the best bargain analog synthesizers out there. It's the Gakken SX-150, a stylophone styled analog that can be found on ebay for $40. The machine has to be assembled, but there's no soldering involved. It's just a matter of putting the PCB in the case and connecting the power line, pretty simple stuff really. It's very much a gimmick but since it really is a true analog it's fairly easy to modify it into something useful.

So here's what I added, for reference I'm looking at the board with the PCB text that reads "hechenggi" in the bottom left.

CV/Gate in:

This one is really simple since the cv is tied to the gate, so you only need to wire in a jack and wire the tip to the south side of R7 and the sleeve to ground.

LFO Inputs and Outputs:

Again very simple, you can tap the LFO outputs from the waveform selection switch, to add an LFO input you need to cut the trace between the waveform switch and the south side of R17. You can then add a toggle switch between these points and wire a jack to one side. You will have to add a resistor to ground for the floating side since as soon as the trace is open the tuning changes. With clever use of a two way toggle you can make it so that the internal LFO is disabled when the switch is up and the resistor is tied to ground only when the internal LFO is off.

Disable Pitch Env:

I did this purely for stability, since sometimes the pitch env is still active a little even when the knob was fully off. You need to cut the trace between the south side of R13 and the north pin of the pitch env pot. You can then wire your toggle between these points. Again you'll need a resistor to ground to keep the tuning correct when the pitch env is disabled. Make sure that the resistor to ground isn't connected when the Pitch Env is enabled or you'll loose most of the range on the Pitch Env pot. Exact resistor sizes for this mod and the previous one will vary depending on your power supply settings and control voltage so it's probably best to get a guitar tuner or something similar and try what sizes work best.

Resonance feedback knob:

Fairly simple, wire a 10k pot (as a variable resistor) to either side of R39. If you want to place the pot where I placed mine you will have to remove the power jack and move a capacitor. I extended the legs of the cap as you can see in the following pictures.





Cutoff range adjustment:

I placed a resistor between the north and west pins of the cutoff pot since as stock the cutoff knob only worked for the last 30% of travel. The resistor helped to fix this, again you'll have to experiment with sizes here (if you need to do this). Start with a large resistor and work down until you find a suitable size.

Adjustable power supply:

You can find details on how to make one here, I just made two in one. I would recommend using precision trim pots so you can fine tune the voltage (don't go over 6v though)

Here's the schematic which is a little simplified but could be useful.

DIY 8 Step Sequencer - Updated

Just thought I'd show you the new version of my DIY sequencer. In the last video I had it mounted in the modular on an old CD cover. This was taking up about 24HP so i decided to shrink it down to 16HP. I had to use two doepfer 8HP blind panels since unfortunately they don't sell 16HP ones.

I put the LED's into a nice new arrangement and added last step switches inpsired by the video response to the last video by Synthetik. I didn't have double throw switches, so I had to use single throw. So at the moment it doesn't work without the pitch knobs being at maximum. I'll add some double throw in the future to fix that and add the ability to remove the step from the sequence. I'll also add a clock trigger circuit so that I can drive it from the modular clock.

Of course I'll post a video with schematics for that once it's done, which will probably be the last work I do on this particular project.

All in all I think it looks a lot better now and is much more sturdy compared to the original CD case panel.

DIY 8 Step Sequencer

If you've done the MC-202 mods then this could be a nice addition to your setup. The sequencer is very cheap and easy to build, it's based on the "baby 10". I did a few modifications and plan on making more in the future along with a proper front panel for my modular (right now I used an old cd cover).

I think the total cost of the project is around £10-15 pounds, the main cost being the potentiometers. The mods I did to mine are a 4 step switch,a reset button and output attenuation (it was outputting 12 volts which is a bit hot for my gear). There's scope to add switches to disable steps or output the clock pulses, you could even add a mutli switch to set the last step or set ranges on the output. The scope is only limited by your imagination.

Here's the original article that was inspiration for this project.



And some useful links

electro-music
fonik
audiomidi

Adding proper CV/Gate inputs to a Roland MC-202

For the final MC-202 modification in my little series, here's how to add proper cv/gate inputs. In the video I highlight the differences between the internal inputs (which are quantised by the cpu) and the modification.

This mod requires cutting traces, so a little extra care is needed. Be extra careful when working on the gate part since there's not much to solder to around the CPU. You'll have to scrape off some of the mask on the traces and wire direct to them. Take your time on this and be sure you have done it correctly before applying power to the machine.

How to add raw oscillator outputs to a Roland MC-202 and what you can do with them.

This week I show how to add more oscillator outputs to your MC-202. These include, Square, Saw and Sub Osc. I also show the possibilites of this and the previous mods with and without an external modular.

How to add CV outputs for LFO Sine/Triangle and Envelope Generator on a Roland MC-202

This time I show how to add some more CV outputs to a Roland MC-202. It's relatively simple, all you need is three 3.5mm jacks and some shielded wire. Schematics are below.