the sidrazzi project

this blog documents one of my current diy projects, the build of an electroacoustic instrument called sidrazzi. in the first part the focus is kept on crafting the housing of this wonderful instrument.

electricmusicfox_ciat-lonbarde_sidrazzi_teaser3

introduction to the sidrazzi

the sidrazzi is designed, handcrafted and also distributed by peter b, the mastermind behind the small company ciat-lonbarde. the instrument designs of the ciat-lonbarde family are beautiful and exceptional. wood plays a central role in the designs of ciat-lonbarde instuments, which are typically crafted of solid and colorful wood sheets. the philosophy behind peter’s instruments is grounded on the interaction of body, device and sound, mainly realized with distance or touch sensitive interfaces.those allow a sophisticated and immediate communication between instrument and musician.
my interest for the sidrazzi was raised after testing a sidrassi (the prior hand-crafted version). the sidrazzi is the predecessor of the now available sidrax, which is basically a sidrazzi in a new makeup with a couple of new features. as the tetrax formerly called tetrazzi the newly designed sidrax offers now the same slim and striped ciat-lonbarde look. the main differences of the three versions are:

  • sidrassi (through hole pcb, touch nodes on top, 2 vertical, 3 horizontal and 2 vertical, hand painted)
  • sidrazzi (pcb with SMD, touch nodes on bottom side, 7 vertical bars, printed/stamped)
  • sidrax (pcb with SMD, banana jacks, 7 vertical bars, tuning pots, chaos-cv, master tune-cv, slim sandwich-style and striped-look)

architecture
like all instruments of ciat-lonbarde the sidrazzi features an exciting and  unique instrument design. it consists of seven identical voices with a triangle waveform. in contrast, the tetrassi family uses a ramp waveform, which results in higher harmonics. the sound of a voice is played by striking or pressing a wooden bar. flexing and tension is captured by a sensitive piezo which is attached underneath it. the pressure sensitivity allows a kind of aftertouch capable of sustaining and modulating the sound. a triggered note is auto-panned at the stereo output given by the on-set and release phase of the piezo. additionally, the design features six touchable contacts, which can have a huge impact on the sound (in: osc glitch left, osc glitch right, fm modulation, out: osc, bar pressure, bar releasal).

from sidrassi over sidrazzi to sidraszi
unfortunately, in the beginning 2013 the new sidrax wasn’t released yet. thus, i decided to go the diy route and ordered the pcb of the sidrazzi. my sidrazzi version is a mixture of the old sidrassi and the sidrax (in the strict sense i was inspired by the feature set of the tetrax, namely the tune pots and the banana’s, since the sidrax wasn’t released at the time as i started with this project). i want to call my version ‘sidraszi’, because i used the original layout of the sidrassi with the guts of a sidrazzi.


my design of the sidrassi includes for each voice:

  • tune pot
  • auto tune button
  • trigger/cv input
  • external piezo input
  • switch: tune/auto-tune
  • switch: audio range
  • touchable bananas on the top
  • touch nodes underneath

the challenge of this build for me was to include all of these features at a compact size, since i intend to take it ‘car-less’with me on gigs. a picture says more than 1000 words, so i’d like to show some snapshots of the birth of the sidraßi…

crafting the bars
this handmade xylophon was the basis of the selfmade bars.

electricmusicfox_ciat-lonbarde_sidrazzi_xylophone

the bars were cut and recessed with the help of a miter saw.
electricmusicfox_ciat-lonbarde_sidrazzi_barres

1st preview: estimating roughly the spacing of some elements. i toyed around with many different layouts, but in the end the classic sidrazzi layout was most convincing.

electricmusicfox_ciat-lonbarde_sidrazzi_1stpreview

planning phase

beforehand, i decided to arrange the parts in a technical drawing. this was done in the freeware LibreCAD. however, the layout of the elements is only possible after sourcing and ordering all parts.
electricmusicfox_ciat-lonbarde_sidrazzi_cad
the scan of the pcb is used later for placing the holes on the bottom plate. the layout of the pcb looks wonderful…

electricmusicfox_ciat-lonbarde_sidrazzi_1stpreview_pcb

drill commander

the technical drawing was printed out on a scale 1:1. luckily, my draft fitted on an A3 printout.

electricmusicfox_ciat-lonbarde_sidrazzi_1stpreview_printout

the printout was glued carefully with double-faced adhesive tape. since the front-panel was pre-cut, it is crucial to pay attention that the drawing was exactly in line with panel edges.

electricmusicfox_ciat-lonbarde_sidrazzi_1stpreview_frontpanel_with_cad
afterwards, the center points for drilling the holes were marked with a sharp tip and stamped afterwards by a punch mark.

electricmusicfox_ciat-lonbarde_sidrazzi_1stpreview_frontpanel_marking

many holes (and a day later) the front-panel, putting in a German phrase, looked like swiss cheese, this means: 7 x (7 x bananas + 3 x barres + 2 x switches + 1 x pot) + 1 x led + 2 x slider = a lot of work…

electricmusicfox_ciat-lonbarde_sidrazzi_1stpreview_frontpanel_drilling

however, for the frames there are still many holes to be drilled: 7 x (1 x button, 1 x trig, 1 x piezo) + 2 x out + 1 x switch + 1 x power

construction of the housing
many (and a few frustrating) hours later, the housing was done. on this picture the raw cabinet was already sanded with emery and waited for the painting.

electricmusicfox_ciat-lonbarde_sidrazzi_1stpreview_01
for the type of wood beech was used (fagus sylvatica), which is rather strong and heavy. it is important to note that beech slats had to be pre-drilled before knocking the nails. this avoids a potential cracking of the slats.

electricmusicfox_ciat-lonbarde_sidrazzi_1stpreview_02
however, i was still a little bit afraid that the front-panel might be too weak, if the barres are operated with a lot of pressure. thus, an aluminium plate on the internal side (not shown here) is supposed to stabilize the panel. since the shaft of the jacks are too short to mount them on thicker wood panels, a center bit with a diameter of 22mm comes in handy to solve this issue.

electricmusicfox_ciat-lonbarde_sidrazzi_1stpreview_bottom

artwork and finish

the artwork was printed with old stamps used for letterpressing. the printing was done with a water soluble printing acrylic paint. before printing, a grounding was applied with a water-based matt varnish.  this protects the printing for smearing out along the wood fibres due to diffusion. the paint was coated with a printer roll as used for lino printing. since it is difficult to print with the metal stamps directly on a solid surface, an intermediate print on a sponge rubber is necessary. the flexible rubber allows an effective stamping of the figure on the wooden surface.  after the printing the surface was sealed with an epoxy based varnish.

electricmusicfox_ciat-lonbarde_sidrazzi_printing_tools

mounting of the parts
left part of the sidrazzi with the touch sensitive (conductive) banana jacks.
electricmusicfox_ciat-lonbarde_sidrazzi_case_with_parts_leftview fomr the right:  the sliders are master tune and chaos control.
electricmusicfox_ciat-lonbarde_sidrazzi_case_with_parts_right
the bottom plate is made of acrylic glas. it allows the view on the beautiful pcb. in addition to the touchable bananas, there are also touch points mounted at the bottom plate. the holes where drilled by using a 1:1 copy of the pcb as a template which was simply glued on the protective sheet of the acrylic glas.

electricmusicfox_ciat-lonbarde_sidrazzi_cas2_with_parts_plexiglas

view of the inside: since there is not so much room left, the mounting will defintely become a challenge…

electricmusicfox_ciat-lonbarde_sidrazzi_cas2_with_parts_bottom
with the  picture of the inside i finish the 1st part of my sidrazzi project. the soldering and mounting of the pcb is still in process. it will be presented in another part of my blog. thanks for reading!

acknowledgments

many thanks to peter b., weinglas, pannikel, haesslich, beni and last but not least hermann.

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