DIMI is reborn
The project of cloning DIMI-A was initiated in the spring of 2014. At that time I was working on a project with Icelandic artist and instrument builder Halldór Úlfarsson on a project involving original DIMI-A. Based on his suggestion I decided to apply funding for making a copy of DIMI-A. DIMI-A is synthesizer by Erkki Kurenniemi and the first synthesizer under DIMI line from the early 1970’s. It is a synthesizer with programmable digital sequencer. I also like to describe it as a tracker  without display. I managed to get project funded and started it in 2015, and this article will document the starting point of the project.
This project did not come out of nowhere. I have been studying Kurenniemi instruments for more than ten years. I have written several articles about them [2, 3, 4, 5]. Latest one, focusing on DIMI-A and DICO was recently released by The MIT Press. I have also been performing with the original instruments on numerous occasions, even together with Kurenniemi himself.
Here is an extremely short version of the history of DIMI-A. Kurenniemi (with his team) started to work on the instrument during winter 1969-1970. The instrument was finished during summer 1970. DIMI-A was given name DIMI (after digital music instrument) and soon afterwards renamed to DIMI-A after development of the next instrument, DIMI-O, started. Two almost identical versions of DIMI-A were made. One DIMI was sold to Helsinki University Electronic music studio, where it is still in use today. The second one was sold to Swedish composer Ralph Lundsten, who used it for few years and then donated it to the collections of Musikmuseet in Stockholm (currently merged with Swedish Museum of Performing Art). [7, 3, 2]
Ralph Lundsten shows kids how to play DIMI-A (while his copy was still working) and some other Kurenniemi synths (in Swedish).
The most important reason to pick DIMI-A of all Kurenniemi instruments as main subject of this project is that while being the most iconic of all Kurenniemi instruments, it is the instrument with least information available. All other Kurenniemi instruments have fairly complete documentation. This can include schematics, timing charts, sketches, part lists and so on. But for DIMI-A there are none. During last ten years I have tried unsuccessfully to source them with Kurenniemi and few others. It is highly likely that documentation has existed, but currently we do not know if it still exists or if it has been destroyed at some point. The plot thickens when you lift off the the keypad board and have a look inside. More than 100 IC circuits, most of them without markings as they have been wiped away with acetone. Effort has surely been taken to protect ones intellectual property.
Studying historical instrument as this is not just about electronics. It is also about the history. In case of DIMI-A it is about the history of (Finnish) electronic music, Finnish underground scene and the history of technology. There are many stories to be told about the instrument. Some of them you will find by simply looking at the finished instrument. It has an aeroplane power cable between its power supply and the actual instrument. It has a model railway banana connector connecting probes to the modified magnet keeper plate. The fact that the circuits are wiped and the schematics are missing are a hint of another story.
DIMI-A is linked to the founding of Digelius Electronics Finland but was finished before founding of the company. Instruments made before DIMI-A were built in the premises of Helsinki University Studio. Few existing photographs of the finished instrument are also from the University studio. However the instrument was most likely built in the premises of another electronic instrument company, Elektromusiikki Oy . Elektromusiikki was company selling mostly electric organs, electric accordions and discotheques (”two turntables and a microphone”) and was run by Jouko Kottila, who would also be one of the founders of Digelius Electronics Finland. Elektromusiikki was also a place were many key figures of Finnish underground scene were hanging out at that time, but nowadays very little is known about the place.
The difficulties in projects like this is that even if the original instrument was not built that long time ago, 45 years is still a long time. It is such a long time that memories of the people involved start to fade and melt together; someone might remember clearly working on instrument on some location with someone, but what the actual instrument was and what the actual location was might not be so clear anymore. People don’t simply remember. Ask me about the project I have done few years back and I would not be able to tell you much.
Technology obviously plays an important role in a project like this. Companies producing electronic components and mechanical parts did not spend too much effort on documenting what they were doing and when. True to even most legendary IC circuits is that in many cases their birthday is not known . These are only few examples. Reverse engineering an electronic device with very little documentation and tens of wiped ICs is another remarkable problem, even though it is much easier nowadays than it used to be. And was not impossible even back in the day.
The point of actually building a working copy of the instrument might seem pointless. But it is the actual work that forces you to pay attention to the details that might be trivial or not. Trying to source a component might reveal why it was chosen in the first place. Kurenniemi might use some bit as it really made sense. Or maybe it just was available? Or it just happened to by at hand? The beauty is in details. And when you are building a copy of a synthesizer from scratch you really need to check every detail, there are no shortcuts.
This research project is funded by Finnish Cultural Foundation. Outer space photo was taken by Veera Knuuti and Digital City live picture by Kati Heickell.
 Wikipedia. Music Tracker. url: https://en.wikipedia.org/wiki/Music_tracker (visited on 11/04/2015).
 Jari Suominen. “ Erkki Kurenniemi’s Electronic Music Instruments of the 1960s and 1970s”. In: Erkki Kurenniemi – A Man From The Future. Ed. by Maritta Mellais. Finnish National Gallery, Central Art Archives, 2013. url: http://www.lahteilla.fi/kurenniemi/julkaisu/Suominen.pdf.
 Mikko Ojanen and Jari Suominen. “ Erkki Kurenniemen sähkösoittimet”. In: Musiikki 3-4 ( 2005). url: http://helda.helsinki.fi/bitstream/handle/10224/3874/ojanen-_suominen.pdf.
 Kai Lassfolk, Mikko Ojanen and Jari Suominen. “ DIMI-6000: An Early Musical Microcomputer by Erkki Kurenniemi”. In: Proceedings of the International Computer Music Conference. Athens, Greece, 2014. url: http://www.smc-_conference.net/smc-_icmc-_2014/images/proceedings/OS13-_B11-_DIMI-_6000.pdf.
 Mikko Ojanen et al. “ Design Principles and User Interfaces of Erkki Kurenniemi’s Electronic Musical Instruments of the 1960’s and 1970’s”. In: Proceedings of the International Conference on New Interfaces for Musical Expression. New York City, NY, United States, 2007, pp. 88–93. url: http://www.nime.org/proceedings/2007/nime2007_088.pdf.
 Kai Lassfolk, Mikko Ojanen and Jari Suominen. “ Interaction of Music and Technology: The Music and Musical Instruments of Erkki Kurenniemi”. In: Writing and Unwriting (Media) Art History. Ed. by Joasia Krysa and Jussi Parikka. The MIT Press, 2015. Chap. 19. url: http://mitpress.mit.edu/writing-_unwriting.
 Erkki Kurenniemi. “ Private interview (MP3) by Mikko Ojanen and Jari Suominen at Helsinki University Electronic Music Studio, Vironkatu”. June 2004.
 Jouko Kottila. “ Private interview (MP3) by Mikko Ojanen and Jari Suominen at Helsinki University Electronic Music Studio, Topelia”. June 2014.
 Brian Santo. 25 Microchips That Shook the World. 2009. url: http://spectrum.ieee.org/semiconductors/processors/25-_microchips-_that-_shook-_the-_world (visited on 10/27/2015).