Ciat-Lonbarde Tetrazzi Organus Eurorack Modular Synth Module DIY conversion – with added CV control !

This is a photo tutorial on how to “eurofy”a tetrazzi organus. The tetrazzi organus is a touch sensitive synthesizer that generates highly banded sounds using piezo trasducers attached to rigid boards – press barres. In my implementation y shall teach you how to make the press barres CV controllable with + AND – voltages (you cannot believe how freaking good this sounds!). Additionally i suggest how to construct a euro faceplate and how to power the tetrazzi board using your onboard Doepfer style cable and power supply. This is a physical contraption that I deliberately named E.U.R.A.Z.Z.I.

Why did I do this? because the E.U.R.A.Z.Z.I. was instrumental on interpreting my 2003 graphic score composition entitled “Sonnet“. This composition is based on the juxtaposition of, (i) numerological findings and (ii) musicality features, both systematically extracted from the poem “Sonnet” by Federico Garcia Llorca:

I do not wish to distract you from your eager DIY intentions but, if you want a taste of the E.U.R.A.Z.Z.I’s capabilities you can check “Sonnet” track as follows:

Federico Garcia Lorca - Sonnet

   I know that my profile will be serene
in the north of an unreflecting sky.
Mercury of vigil, chaste mirror
to break the pulse of my style.

   For if ivy and the cool of linen
are the norm of the body I leave behind,
my profile in the sand will be the old
unblushing silence of a crocodile.

   And though my tongue of frozen doves
will never taste of flame,
only of empty broom,

   I'll be a free sign of oppressed norms
on the neck of the stiff branch
and in an ache of dahlias without end.

The tetrazzi organus is defined by Professor Blasser as follows:

“Tetrazzi is the newest incarnation of the Organus series, a mandala of analog oscillator circuits that can cross-modulate to form the empire of infinite circuitry known as pure sonic chaos. Electronically, it represents some of the more profound electronic complices that were developed in the 20th century,  such as Buchla Source of Uncertainty,  U.S. Navy Phantastron Radar Circuit, and Piezoelectric Flex Technology. It is a way to make the touch-sensitivity of human organs into touch-sensitivity on the pipe organ, pipe here meaning “squishing electron flow via ceramic transducer”.  You got to love this man!

Step 1: assemble the tetrazzi board as per Senior Blassier instructions

Step 2: I used a Doepfer A-100B42 42 HP / 213 mm blank panel as a guide to cut a wood front panel from a 3.5mm timber sheet.

Step 3: give it a bit of a sand and mark the mounting holes.

Step 4: cut another sheet of the same height but 5-6 cm narrower – this will make your press barres

Step 5: divide the 2nd sheet on 4 equally sized press barres … ca va?

Next … step: i have a jigsaw + I am sloppy so i have to sand them all down to straight sides!

then … your press barres sould look like this 

the next step: get some M3 screws/nuts and place your press barres – the nuts will serve as spacers that will elevate all barres at the same height. it is also a good idea to number all barres 1 to 4 and make sure that:

1. you drill and place the screws so that you clear the mounting rails

2. the screws can conduct electricity – they will be your bend/touch points (4/barre)

take the plunge into the next step! … give your timber tender loving care with a bit of oil or varnish … make it look gorgeous!  

what’s up now? another step: drill and mount

1. x4 momentary switches

2. 4 pots – 100K

3. L-out and R-out (middle left and right jacks)

4. x4 CV in jacks for press barre modulation

… also drill 4 holes for press-barre piezo cables to be solder into the tetrazzi board

LooKing GooD! don’t you think? –

step (n+1) … attach the tetrazzi board to the back-panel … i used PCB stick-on elevators – – you might also use brackets – crews+PCB separators … you decide my friend!

now solder all panel components to where they suppose to be according to ciat-lonbarde’s assembly instructions … i will tell you how to wire your barre-CV-in’s soon – do not despair amigo.

now, how to build and connect you Doepfer-style ribbon connector … the next image will tell you that you would solder all GND pins together and all +12 volts pins together and then just connect +12 and GND to whey belong in the tetrazzi board (the PSU adapter points)

now triple-check your doepfer jack since you now shall epoxy this baby onto the board and against one on the jack triplets. Use clamps to assist epoxy-driven union and let cure according to your epoxy instructions

voila … you have officially EUROfied a tetrazzy – since you have all that epoxy goo mix drying out, hurry and glue the piezos to the barre boards and then attach the barres to your panel – remember – one nut serve to elevate the barre from the panel and a 2nd nut shall secure it to the dorsal/back panel. do not forget to solder the piezos on the board  🙂

ahora … otro paso: give your baby its umbilical cord – she is hungry!

well, the time has come, i’ll let you know: for your barre-CV-in’s, wire GND of each CV jack (the closest jack-pin to the panel) to its corresponding black/GND piezo connection at the board. the connect each CV-jack-tip-pin to a 330K resistor and the other end of the resistor to the red/positive piezo connector at the board. if you have an eagle eye you can see this at the next couple of pics …

happy chappy ? you bet – you have build a tetrazzi organus into your eurorack modular synth. you can CV-modulate it using bipolar voltages and also play-it with your pressure gestures concomitantly

if you build one of these … please let me know and send some pics: that will pay-off the time and effort that I invested into this post. lots of love,



Pseudo-seizure vii -2010

This is my second submission to sound lab and due to the 10th anniversary I decided to share my most recent piece which belongs to a series called pseudo-seizures with aura. Pseudo-Seizure7 was conceivedafter a 3 month placement at a

Hospital’s Neurology Ward. I exploredthe aesthetics of auras during the preamble to an epileptic seizure by interviewing 2 selected epileptic patients who experience recurrent auditory auras (hallucinations) during status epileptics. I generated an extensive series of soundsamples based on these patients’ descriptions. The 2 patients then listened and ranked these sound samples in terms of their resemblance to their auditory aural experiences. To my surprise the samples that ranked more highly came from harsh textures generated by one of my vector synthetiser (TG33 partly designed by Dave Smith for Yamaha back on the days …). With this insight I then generated 11 sound-scapes of which number 7 is the current submission. In addition to these ‘synthetic epileptic auras’ there is a dodecaphonic percussive line which is a mapping of 12 relevant ‘electric events’ extracted from epileptic electro encephalograms (EEGs). The mapping is so that a 12 note system maps epileptic markers and the rhythm is a direct temporal map of when these epileptic events happened – in real time.


To conclude, the following is a prosaic deconstruction of the physiopathology associated with temporo-parietal seizures with aura. In my opinion a knowledge of this biology is fundamental so to empathise with epileptic patients. I highly recommend reading this some-how-non-sense-paragraph before listening … enjoy the music.

“auras – from – 80% of temporal lobe seizures + common feature — simple partial seizures +++ precede complex partial seizures of temporal lobe origin -~ “auditory hallucinations” :: ‘buzzing’ sound – ‘voice or voices’ or muffling or ambient or harsh sounds. ?neocortical temporal lobe epilepsy vs ?other types of temporal lobe epilepsy. ->Following the aura, a temporal lobe complex partial seizure begins ->> wide-eyed ->>> motionless stare ->>>> dilated pupils ->>>>> behavioral arrest, ‘oral alimentary automatisms’ ‘lip smacking + chewing. Manual automatisms too. or unilateral dystonic posturing of my limbs – could be one or more. most auras and automatisms last a very short period—seconds or 1-2 minutes. The postictal phase may last for a longer period (several minutes, perhaps 14.21 minutes). By definition, amnesia occurs during a complex partial seizure because of bilateral hemispheric involvement – so –

Intermedio – 2010

Improv during the virtual launch of Lopez-Donado latest submission to Media Fest’10.Lopez-Donado used the following instruments during the 13+mins improv: Premier modified drum-set + cocostuber + modified microphonics

inspired on ‘Romance de la pena negra’

Las piquetas de los gallos – cavan buscando la aurora, – cuando por el monte – oscuro – baja Soledad Montoya. Cobre amarillo, su carne, huele a caballo y a sombra. Yunques ahumados sus pechos, gimen canciones redondas. Soledad, ¿por quién preguntas sin compaña y a estas horas? Pregunte por quien pregunte, dime: ¿a ti qué se te importa? Vengo a buscar lo que busco, mi alegría y mi persona. Soledad de mis pesares, caballo que se desboca, al fin encuentra la mar y se lo tragan las olas. No me recuerdes el mar, que la pena negra, brota en las sierras de aceituna bajo el rumor de las hojas. ¡Soledad, qué pena tienes! ¡Qué pena tan lastimosa! Lloras zumo de limón agrio de espera y de boca. ¡Qué pena tan grande! Corro mi casa como una loca, mis dos trenzas por el suelo,

de la cocina a la alcoba. ¡Qué pena! Me estoy poniendo de azabache, cama y ropa. ¡Ay mis camisas de hilo! ¡Ay mis muslos de amapola! Soledad: lava tu cuerpo con agua de las alondras, y deja tu corazón en paz, Soledad Montoya.


Por abajo canta el río: volante de cielo y hojas. Con flores de calabaza, la nueva luz se corona. ¡Oh pena de los gitanos! Pena limpia y siempre sola. ¡Oh pena de cauce oculto y madrugada remota!


5 Kinds of Tears, part iii – 2011

This is part iii of my current body of work entitled 5 kinds of tears. Catalina de Siena, in her seminal work The Dialog, includes a chapter on which she classifies tears in 5 classes. Following, a prosaic pseudoscientific breakdown of my interpretations and the motivation for these 5 films:

I. Bad Tears: these engender death. They proceed from mortal sin and conduit towards it in a perfectly closed system. These are tears associated with hate, and desperation – they come from disorderly/issolated hearts. Nevertheless, they are considered perfect.

II. Tears of fear: fear to our own sins. They awaken us from sin out of deep fear of falling. These have unfounded motivations since they are not necessarily associated with redemption.

III (this film). Tears from servants: those that are associated with souls seeking to serve but realize the inherited loss and solitude. These gravitate around deprivement from visible consolation and are fundamentally centered on desperation and frustration due to the imperfections of the system. These are inconclusive tears within an open system, yet imperfect.

IIII Perfect tears: are those that emanate from souls that love in a perfect manner. They are based on frustration towards souls described at III.

V Sweet Tears: these are imperfect, yet more elevated that those in IIII and I. They are part of an infinitesimal impulse which occurs within a bilateral stare. At that moment two souls collapse and there is no time for tears to emerge. Nevertheless, they exist theoretically and, although imperfect, still qualify as the most elevated form of tears.

Lopez DoNaDo

While studying music theory/composition at the Music Conservatory of Caracas Jose Angel Lamas, Dr. Jesus Lopez-Donado received his BSc (Hons) in Electronics Engineering from the Simon Bolivar University (Venezuela) in 1997, later, his Ph.D. in artificial intelligence applied to signal processing from the University of Ulster (UK), in 2003 and his postgraduate certificate in education from the same institution in 2004. He has exhibited several installations and performed with a number of experimental bands. In February 2000 he joined the School of Information Engineering at the University of Ulster as a lecturer in multimedia and bioinformatics. He then emigrated to australia and became an A/Prof in informatics at USQ. He has being associate editor in the Proceedings of the International Conference on Artificial Intelligence and an invited editor for the IEEE Transactions’ series. His research interests are in, computational creativity (biological complexity applied to music), bioinformatics, medicine and generative music. He has published over 30 peer-reviewed articles, one edited book (available here) and one monograph (available here). Pursuing more humanistic goals, he commenced post-graduate medical studies (2007-2010) at Griffith University Australia. He believes that, despite an ubiquitous demand for specialization in modern society, the idea of a modern homo universalis (polymath) is still fundamental and achievable by fully integrating artistic, humanistic and scientific endeavors within a sole ideological framework.