lauantai 17. maaliskuuta 2012

DIY Ribbon Cables

I think ready-made Eurorack power ribbon cables is quite expensive, at least these commercial ones which cost around 5 € each, depending on brand.Of course if you buy new module, cable comes with it, but for DIY modules you have to buy one or make your own.

Much cheaper option is make your own IDC ribbon cable. What you need is some IDC connectors and ribbon cable. For most modules you need to make cable with 10 contact IDC connector in another end and 16 another. 16 way connector goes to bus board and 10 to module.
Some commercial modules have 16  to 16 , but that´s more rare than usual.

I bought cable and connectors from Futurlec. Gray 10 way ribbon cable cost 0.40 $ per meter and  10 or 16 Contact IDC Socket Connector cost 0.25 $ each + S & H.

Well, without any maths here, it´s under 1 € per cable. Now, that´s a reasonable price for a cables!

Assembly is pretty easy, but you have to be careful to avoid any bad socket installs.. thought.
Leakage between single cables might cause short circuit and destroy your module eventually and that is not  something what we want!
It´s good idea to first press connector and cable smoothly together with your hands. Be sure to use enough power, so socket stays in it´s place and doesn´t fall off . Check cable that it´s in right position and there isn´t any noticeable misplacement,  then tighten up between vise jaws.

Let´s take a closer look DIY IDC ribbon cable assembly:

Connectors come in three part construction. First two from right is actual connector and part in left is cable holder.

Cable and connector firmly tighten together. Left side is 10 pin connector and 16 pin in right. Take note if you are making power cables for Eurorack modular system, 16 pin connector should be installed like in picture below. Connecting cable to the another side of connector you get int.gate, int. cv, + 5 V, +12 V and gnd from bus board. What we need  is -12 V, gnd, +12 V. Red stripe in cable indicates - 12 V. More info about bus board pin outs from  Doepfer technical details.


Almost there, tightening connector between vise jaws.

Installing cable holder.

 All done!

torstai 8. maaliskuuta 2012

MFOS Dual Vca #2

Today i finished new module to my forthcoming modular system,  MFOS Dual Vca #2 . This is an older version of  Ray Wilson´s Vca , but as Ray has written on his website, it´s still very viable design.

perjantai 24. helmikuuta 2012

DIY modular project (Case)

My DIY modular project moves forward slowly, but surely. I did choose  Eurorack format for my weapon of choice mainly, because few of  my friends also builds DIY Eurorack modules, so we can share information and of course do some group buys for different components like pots, jacks etc.. and also there is quite massive collection of commercial modules available.

I already have finished couple of modules like LFOs, multiples(passive and buffered) and several different modules is almost done like VCAs, ADSRs and Oscillator.

At the moment i´m building case for my system. I found these new 3 U  rack-mountable cases (Eurorack compatible) from local internet auction site. Seller had 3 of those, so i bought them all. Only 18 € per each, so 54 € for 9 U system is not bad,  including  all the hardware i need to mount my modules.
For powering everything i bought Doepfer A-100 DIY Kit 1 (114€) and also i had to buy some L-profiled aluminium and some 6 cm wide aluminium strip, so i can install more easily  Doepfer bus boards back of the   case.
I probably going to build nice 19 inch hardwood rack for this system, but future plans in mind, i try to connect everything to this 9 U aluminum case so i can easily move it to bigger case in future if needed.

So far i have spent roughly 200 € for this case and  even if i put 50-60 € more doing this hard wood rack for it, it´s still going to be cheaper than any 9 U commercial case available. Not to mention it´s going to be hard wood and not any plywood or plastic.

Some building photos....

Making markings for drilling holes.

Drilling done. I´m quite happy with results considering i used basic hand drill for drilling holes.

I didn´t have any spacers around, so i had to do my own. I had this 6 mm wide aluminum tube which was perfect for making spacers. Simple but effective way cutting is using stopper to get same length pieces.

Assembly, screws, nuts and washers.

Work done. Next i had to install these to frame.

 Bus boars in their place. There is also drilled holes for third bus board if i want to add one more later. Doepfer´s kit only contained 2 bus boards.

Top view

Next i have to install power supply. Probably i´m going to use same method as i used for bus boards, but let see. Also i´m thinking to add XLR connectors between transformer and power supply, so transformer would be removable.....

Edit 27.4.2012

Installing XLR connectors and power supply. I used this same 6 cm wide aluminum strip which was wide enough to house power supply. 25 mm hole for XLR connector was little bit harder task to do, because i didn´t have any this caliber drill bit. I had this small metal saw which worked pretty nicely for this job. Not a perfect hole, but good enough.

Parts ready for soldering. Power supply already mounted to panel.

XLR connector installed. Green/yellow cable is for grounding.

All done! Time to fire system up.

tiistai 3. tammikuuta 2012

keskiviikko 30. marraskuuta 2011


There´s  always something fascinating about these weird little synth/drum boxes and DCM8 isn´t no exception.
This  chip tune drum machine by VXXY is somewhat cool looking and desirable neat little blue box and if "chip" drums is your trick of treat, then look no further.


maanantai 28. marraskuuta 2011

Minimum Theremin

I´ve always dreamed about building  Theremin and when this Arthur Harrison´s design  came across after doing some schem searching in internet, i knew i found what i was looking for.

I´m still missing few components for this project, but i have to do inventory before ordering any missing parts. (for this and several other projects). But i hope i get this done before Christmas. 

More info about Art´s cool  Minimum Theremin


I did this front panel for my Theremin project. There´s holes for pot and switch and also there is a amethyst in the middle. I´m going to put blue led underneath it, so i can´t wait to see how it is going to work out....should be cool light fx, but can´t tell yet.


Instead of using perf board i used ExpressPCB software to draw my own PCB. After drawing was done i  printed it to film and then etched it.

NOTE! If you are looking PCB or full kits for this project you can buy those directly from Harrison Instruments.

When i started soldering stuff to board i noticed there was a one mistake on my pcb, but thankfully it wasn´t too hard to fix. Just added one jump wire.
Soldering done, still missing ICs, enclosure and antenna.


Finally i had some time to finish this project. Actually it didn`t work at first try, but after some troubleshooting i found out i had soldered voltage regulator wrong way. After correcting this, it worked nicely

Ready for playing!


After some test playing with headphones(and not with these cheap computer speakers what i used during my first test) i noticed there was an annoying distortion in sound once in awhile.  I found out that antenna is taking some sort of interference from front panel. Maybe it´s just too close to antenna, but anyway solving this issue i tried to ground front panel and it worked. Hurray!

Here´s a short demo of Minimum Theremin,

Minimum Theremin Demo