ECCO is a steel wired duochord.
It fits into my city backpack, it is foldable, and is as a constant companion for concerts & performances.

I play it with sticks, bows, hands, preferably laying on a table. It’s nice for basslines, percussion, drums and bowed screams and flirrrrrs.

ECCO has two pickups.
A cheap movable single coil emphasizes bass/body, whereas a 4 € contact clip gets you wood, so more direct accentuation.
In my 2018 version both are soldered to 480 ohms resistors, then to the same tip on a mono Neutrik 1/4” plug.

I use ECCO partly in conjunction with Sweef and Dromedar/y, oftenly for contemporary dance music.

Sound example (the beat in there)

ecco - by jayrope 2014

ECCO was preconceived and built in 2013 for a dance production at Theater Bremen. You see version 2 here (on the left).

el carrito - jayrope 2014

Version 1 could not be tuned and maybe i liked the tone and unpredictability of version 1 even a bit more. However, now includes machine heads.
ecco - by jayrope 2014

Building instructions below.

Materials
(all screws Philips)
- one board of wood (i took solid pine) 80 × 7 × 1.8 cms
- one wood spacer, solid pine, 7 × 2.5 × 2.5 cms + 2 wood screws 3.5 × 35 mms
- 2x electric bass machine heads & 8 wood screws 2.5 or 3 mms x 1.2 cms
- 2x black coated steel wire (ø 2mm) – length about 85 cms., ends lashed/riveted (typically used in theatres to “invisibly” fly people around on stage – max tensile load 250 kgs.) Experiment with your own type of strings.
- one Gifmen acoustic guitar pickup (single coil, 1 long magnet, 15€, Taiwan) for the bass (fixed with a cable binder 25 cms, then can be moved on the board for sound adjustment, VERY useful)
- one 5€ contact clip mic for finger noises, attach to board or bridge, adjust to taste
- one thin cable binder
- 2 small steel pieces 5 × 2,5 × 1 + 8 × 2.5 × 1 cms of steel for saddle and bridge. You can use wood, sounds rounder. Steel has more sustain and gets you harder percussive attacks.
- for foldability you’ll need one hinge with 4 screw holes on either sides and 8 wood screws 3.5 × 16 mms.
- 2 wood screws 3.5 × 35 mms (or thicker) and
- Washers and screws to attach strings to the wood at the other end ripped off at some point and have been replaced by big hexagonal screws driven through the board directly. I’ll update the images at some point.

ecco - by jayrope 2014

Building
If you want to make it foldable (then fits into suitcase or backpack) you’ll need a rotating saw or another very straight sawing tool to cut the board into two pieces of equal length.
Plus a drill to do holes for machine heads, plus a stable Philips screwdriver or a Makita (easier).
Measure the diameter of the machine heads, then choose drill size accordingly.
I found the steel wires in a theatre here.
Experiment with different steel string thicknesses, however, i use 2 mm black coated. Thicker steel rope quickly puts a lot more load on wood and machine heads.
Similar material is listed here.

Enjoy