I finished the electronics to drive the ‘waterfall’ for the Nachtmusic performance. The electronics switching the water pump can be adjusted to switch off the waterpump when the noise near the waterfall (people talking, music) is too loud.

The electronics consists of the following parts:
1. An opamp switched as a peak detector (measuring the amplitude of the incoming audio).
2. A comparator. Comparing the amplitude with a variable (potentiometer) dc-threshold.
3. Schmitt trigger, to avoid the relay switching on/off constantly.
4. A circuit with two transistors creating an adjustable time delay for switching on and switching off the relay.
5. The relay itself.
6. The +12V power supply with a 7812.

We tested the first bow, made bij Kees van Hemert. It’s a carbon bow newly made with metal ‘hairs' or wires. When the bow touches a string, it indirectly switches on/off the audio track linked to this string. It works really very good. You do not hear any contact pulses, but only a nice soft audio-switching. A nice concept, switching audio with old fashioned light bulbs!

To complete the electronics and the documentation, I also made an overview of the connections. Now it's also clear for other users (i hope).

Today we spend time to repair the VT-VFG of Bea-5. We did get assistance from Jo Scherpenisse, technician, and former colleague of the EWP, who designed a lot of modules, still in use in the Analog studio.

The VT-VFG did have problems with the manual (switch) shift input and the external shift input. When using the manual shit input (by pressing a button), the electronics sometimes skipped some steps. Very annoying for the users and it needed to be fixed.

The electronics for 'Nachtmusic' is finished and ready to be tested. It consists of a circuit that converts light intensity into amplitude modulation; in other words, the more intens the light bulb is lighting up, the more output volume the user will hear.

This week I started building the new electronics for Dick Raaijmakers piece, 'Nachtmusic'. Four string instruments will be used as 'audio switches'. The original design by Dick Raaijmakers was modified and improved by Godfried-Willem Raes. http://www.logosfoundation.org/kursus/2126.html

As a part of 'Nachtmusic' there will be a small waterfall on stage! In combination with the sounds on stage this waterfall will be active or not.
Nachtmusic will be performed in the Springfestival in April 2015 at the Royal Conservatory