torstai 1. joulukuuta 2016

Robertsonics WAV Trigger

Under works is PCB and frontpanel for Robertsonics WAV Trigger that I bought from Spark Fun Electronics ( The PCB and panel creates a frame where WAV Trigger can be fitted. Simple transistor circuits work as comparators that can be fired either from frontpanel switches or from external CV/GATE input voltage (anything between +-10V is OK). My idea was to use this sample player to play some pre-recorded sounds in live-situations. It is polyphonic (max 16 voices) so several samples can be played at the same time. This could also work as a drum machine where drum samples can be triggered from external triggers.

Moog Prodigy PCB version 5.8

This should be the final version of my Moog Prodigy Eurorack clone. Here is what I have done:

- some corrections and enhancements to the PCB
- fastening holes to allow some other frame format than Eurorack
- all the pots (Alpha 9mm PC mount right-angle) and switches (standard PC mount toggle) are now more common format that are easy to source
- new modifications
--> MW MOD SHAPE where LFO is replaced with modulation wheel adjusted CV. So it is possible to sweep the pitch or filter cutoff with modulation wheel. This works also in my previous version and the original Prodigy when you set the MOD SHAPE switch to center position.
--> OSC MOD PW1 where LFO modulates OSC1 pulse width (modulation wheel controls the amount of modulation)
--> External Audio input with level control

torstai 10. marraskuuta 2016

FrontPanelDesigner and HPGL

If you are designing frontpanels with FrontPanelDesigner ( as I am, here you have instructions how to save about 50% in the costs with grouping and HPGL. In my Prodigy-panel most of the engravings are done with 0.2 tool. The lines and bigger texts use 0.4 tool. Normally every engraving creates a new object, so your panel has many objects and the factory charges by objects. It's possible to group similar engraving objects to one HPGL-object, so eventually you have only two engraving objects (one for 0.2 and one for 0.4 tools) and the drilling holes.

1. When I am ready with the design, I save the design in FrontPanelDesigner to another file named Prodigy_tool02.fpd where I leave only the 0.2 engravings and delete all the other stuff. I also save the design to Prodigy_tool04.fpd file where I leave only 0.4 engravings. Third file that I save holds only all the drill holes. Make sure the origin in all these files is in the lower left corner!

0.2 engravings

0.4 engravings

drill holes
Here is the end result!

2. Export the tool02 and tool04 files to DXF files. Do not export the reference points!
3. Import these files to some CAD-tool that can read DXF-files and create HPGL-files. I use the free CadStd Lite-program ( In CadStd I leave only the gravings layer active and export only visible layers to a single pen HPGL-file.
4. In FrontPanelDesigner I open the drill holes file and select insert HPGL engraving. This activates a crosshair tool with which I click the origin (X:0.00 Y:0.00). Select the tool02 HPGL-file, set the tool to 0.2 width, select the color and click "Origin of HPGL file" and OK. Then I repeat this with the tool04 HPGL-file.
5. If you want to save more you can leave the in-fill color out. With this black panel the colorless engravings look very good. You can fill the engravings afterwards manually with Lacquer-Stick paintstick color from Micro-Tools (it is little bit messy but it works)

Panel is ready!

tiistai 18. lokakuuta 2016

Yamaha V50

I bought this synth as a new in 1989. Now the internal battery reported it is dead and it needs to be changed. I new that all the internal sounds will get corrupted in this operation. That's not a problem because there was only one sound that I had programmed. Here is a picture of the main-board where you can see the yellow CR2032 battery. The other picture shows my V50 together with analog-friends SH101 and TTSH2600. I think now I am ready to program more FM-sounds. I have the book "FM Theory & Applications" by John Chowning and David Bristow and the original operating manual for V50. Now I must just start to create new sounds.

perjantai 23. syyskuuta 2016

Prodigy Eurorack Modifications

Here are more detailed instructions on how the modifications are implemented. OSC IN and VCF IN are alredy in the original PCB so they need no instructions.

OFF-position is the original connection. ON-position connects +12V thru R188 to R131/Q39 and opens the 3080 VCA.
When using the KYBD IN V/Oct input you must connect the JUMPER CABLE (see also earlier building instructions in my Blog) so that the KYBD IN is tracked all the time. Leave out the R82 resistor and C23 capacitor. RKYBD replaces the external resistor network.
GATE IN goes direct to R153 resistor. If you are using the original keyboard then GATE OUT must be connected to GATE IN.

Contour Sync OFF-position is the original connection where +12V is connected to Pitch Wheel resistor R180. ON-position replaces this +12V with filter envelope output. When Contour Sync is ON the Pitch Wheel acts like an attenuator where you can choose how much the filter envelope changes OSC2 pitch. When OSC2 to OSC2 Sync switch is ON and this Contour Sync switch is ON then you can change the Sync-sound with filter envelope and Pitch Wheel.
R41 and R48 are both 10k for symmetrical Square. R41 goes direct to +12V and external PWM-input for OSC1 goes between these two resistors.

OSC2 is identical to OSC1 but there is also the R184 potentiometer which adjusts manually the OSC2 pulsewidth.

lauantai 17. syyskuuta 2016

RIP Don Buchla

Synth pioneer Don Buchla has died at the age of 79. Good news is that his heritage is living strong. Composer Suzanne Ciani played with Buchla instruments in 70's and became a good friend with Buchla. Here this heritage is transferred to younger generation when Ciani plays with Kaitlyn Aurelia Smith in their Sunergy project.

Synamiitti 2016 in Turku

I was showing my DIY Moog Prodigy-clone at this years Synamiitti in Turku. Small place but full of synth-stuff. It is always nice to talk with other synth-builders and people that are interested about synths.

The modular corner.

DIY four voice Roland Jupiter.

My Eurorack Prodigy and it's big brother MiniMoog.

Nice DIY MOTM-size modular.

maanantai 15. elokuuta 2016

Electric Druids MIDI2CLK

This is my version of Electric Druids MIDI-to-analog-gate-pulse project ( I programmed the PIC16F688 chip and build this prototype board. It works great. From one MIDI-clock you get two separate analog clocks with adjustable division rate. I noticed that when you change the clock division this chip loses where is the first beat. To correct this you must stop and start the MIDI-clock. This is not a problem for me because I use this module just to convert the MIDI-clock to analog-clock with no division rate at all. I can easily create those different divisions with my Abstract Data ADE-32 Octocontroller ( which is little bit smarter and handles these division changes seamlessly.

perjantai 5. elokuuta 2016

Karelian Skies 2016 Full Concert

Here is the full concert video from this years Karelian Skies!

Alessandro Cortini in Amsterdam

Happily I noticed during my holiday visit to Amsterdam that at the same time Dekmantel Festival 2016 ( was going on in Amsterdam. I picked up from the program Alessandro Cortini performance in BIMHUIS. He had this minimal setup with iPAD working as a sound source and a selection of guitar effects that he used extensively to processing the sound. He created these beautiful soundscapes and little melodies/harmonies with delays, pitch-shifting, reverb and distortion. Distortion can be very beautiful when used deliberately.

sunnuntai 31. heinäkuuta 2016

Compilation Synthe-Modulaire 2016

Active members of French speaking forum about modular synthesizers ( have released again an compilation disk. This years theme was: one-shot recording of instant sequenced multilayer composition.

torstai 21. heinäkuuta 2016

Rob Hordijks new Sync OSC module

A three part video where Rob is showing the new Sync OSC module. Amazing what he can get out from one oscillator and filter. Again worth of listening when Guru speaks!

maanantai 18. heinäkuuta 2016

KS players and their setups

In Karelian Skies 2016 we were seven performers and all had quite different instrument setups. Regardless of that we found very fast common musical language and created some beautiful music.

The Stage with players.
Pertti Grönholm from E-Musikgruppe Lux Ohr. Great collection of old Casio mini-keyboards.
My setup. I played my DIY Moog Prodigy with Akai EWI and Nord Micromodular also with EWI. In one peace I played also Soprano Saxophone.
Petri Frestadius from Sigma. MFB Dominion and Eurorack modular. Some staff from iPAD.
Otso Pakarinen from Ozone Player. Seabord controllers and System 1m. Sound came from OSX.
Teijo Salminen had that great old Roland Vocoder and some other rack stuff.
Jim Combs from Sensitive Chaos. Yamaha Tenori-On sequencer and Waldorf Blofeld. Jim also played the Roland JD-800 synth. Also notice the Hohner Melodica!
Ami Hassinen from Nemesis. Ami had this great keyboard-rig with him. Notice the Ensoniq Fizmo on left. When I get better pictures I will post here more information of Amis setup.

Jim Combs interview

Just came back from this years Karelian Skies collaboration from Nurmes. The week was very nice and rewarding. Here is an video interview of Jim Combs who came from Atlanta USA to play with us in Nurmes.

perjantai 1. heinäkuuta 2016

Karelian Skies setup

I have been playing with this little setup that I am going to take with me to Karelian Skies Nurmes. Main instrument is my Moog Prodigy clone controlled by Akai EWI or eurorack sequencers. I use DittoX4 for tape-loops. TC delays are good basic-delays and Strymon DIG is for more creative use of delays. With DIG and 100% regeneration you can create beautiful delayed soundscapes that are easy to shape and control. Nord Micromodular is also played with EWI.

torstai 30. kesäkuuta 2016


Interesting collaboration between Kaitlyn Aurelia Smith and Suzanne Ciani.
Recording is coming out on September 16, 2016.

maanantai 6. kesäkuuta 2016

Karelian Skies 2016

I'm honoured to play this year's Karelian Skies concert together with great musicians. There are now seven of us and we are going to create together something special for the 16st of July concert in Nurmes-talo. More information here:

www-pages with fotos

sunnuntai 29. toukokuuta 2016

Moog Prodigy alignment notes

Alignment steps are documented in Prodigy's Technical Service Manual. When doing the temperature adjustment of OSC1 and OSC2 I found David Morrins instructions very valuable. When adjusting the temperature trimmer I always checked that the voltage at pin 7 of U2/U4 was negative. If this voltage jumps to positive voltage then the heater circuit is saturated and will not track temperature. If this happens turn the R14/R35 trimmer to other direction so that you get the pin 7 back to negative region.

Original Prodigy's OSC1 is tuned lower (32-16-8) than OSC2 (16-8-4). This is not necessary if you are using the external keyboard-input that doesn't have the 2.5 octave limitation of Prodigy's keyboard. I tuned the OSC2 similarly to OSC1.

lauantai 28. toukokuuta 2016

Moog Prodigy BOM

Here is an Excel-list for the Mouser-parts needed to build my Eurorack Moog Prodigy
Missing from this list are the 24mm potentiometers and the DP3T/DPDT switches.  Also Mouser can not source the CA3046/LM3046 and CA3080 chips. You can try BanzaiMusic for these.
Here is a picture of the 24mm 1M-log Alpha-pot I used for R155,R158,R166 and R169. Shaft length is 15mm and the diameter is 6.3mm. The other potis are similar size and look but from CTS (R83/3M-log, R106/3M-log and R136/50k REV-LOG). I sourced these potentiometers and switches from Uraltone and BanzaiMusic

maanantai 23. toukokuuta 2016

Prodigy PCB 4.4E building details

Other end of resistors R59 and R41 must be connected directly to +12V.
C8 must be a high quality polystyrene or polyester film type.
C14 must be as the C8.
Here is one jumper that is needed.
Jumpers J1 and J2 are also installed. Here you can also see the optional headers at pin 5 of U2B and across R17. These headers make the temperature alignment procedure easier.
Here you can also see two jumpers and the ferrite cable cores in power-input.
Boards 1 and 2 are connected with direct cables. Note that these are not tight so that the alignment to front panel is easier.
TRIG IN must be connected to +12V so that KYBD IN 1V/Oct input is tracked all the time. C23 and R82 can be left out. They create a small CV-glide to KYBD IN. KYBD SCALE trimmer is installed but not used. I keeped the Keyboard current-source electronics (R92,R93,R91,R94,C22,RKYBD) here but it can be leaved out. The other half of U11 must then be bypassed correctly.
Here you can see the alignment headers for OSC2 temp adjustment.
RKYBD can be 200R resistor. This replaces the keyboard resistor divider.
Here is the input connector for 20k resistor and the output of U13A to make the VCA adjustment easier.
The TE Headers are soldered to the bottom side (Wheels and PWM-inputs).
I used only the potentiometers from Doepfers Wheels module.