Work on the circuit continues! An unexciting but important problem to be overcome in any electronic designs is that different chips and components require different voltage supplies if they are to function properly and not explode. We want to be able to power the finished synth from 9v (eg battery or a standard guitar FX pedal power supply) and also 12v for modular synth compatibility. However the AM radio part of the circuit can't handle more than 6v and some other parts we are working with need 5v. So we need to somehow divide the voltage. There are a few methods of doing so. One which appealed to me because it's a counterintuitive hack using very few components is to misuse an LM386 amplifier IC as a voltage divider (an idea I found on this forum thread). You can just connect the +9v and ground pins to your power source, don't put any input signal to the amplifier and it sends out half the voltage! But though it's small and easy, it's not all that accurate and can only chop the input voltage in half rather than give you exactly 5v, so in the end we decided it's better to do it properly with a real voltage regulator. These only require the addition of 2 capacitors to get them working, simpler to use than I expected. For testing we tried the NCP7805 as pictured above, but that is overkill for our power requirements and would take too much space on the board, so we switched to the similar but smaller 78L05. Below you can see it putting out 5.04v, definitely close enough for our purposes. We have been using this to power our test circuits.
In other news, we have the radio part of the circuit working very well now, amplified/distorted using a CD4049 Hex Inverter (another classic creative misuse of an IC, as popularised in Nicolas Collins book Handmade Electronic Music). It picks up both noise and discernible radio signals in an interestingly chaotic way and is highly playable by touching the circuit or even waving hands over it.
For our general research into radio-electronics-as-noise-instruments, and low-voltage tube amplifier + distortion circuits, radio expert Mike Kana very kindly sent us a wealth of rare and interesting vintage components which will be very useful for future Isn'tses circuits! Thanks Mike!
This is the recent. What's happening? it's getting there. There was some problem solving which took a lot of development and we had to change our initial ideas for the synth. We documented some of this by having writing conversations. We developed some really nice sounds which are here:
Writing conversation where we decided that there was too much interference while using the echo chip. We also discovered that when using the radio chip that the human body can act as an aerial.
The drawings have been developed further here with more complex patterns exploring both currents (electrical) and currents (tidal). Drawings by Lisa McKendrick.
Here is an experiement to see how the touch pads might work. The metal stripboard on the left is our touchpad for now.
We researched some of the ways that body contact can affect pitch.
Here are some fellow builders of electronics who we've been greatly inspired by:
Martin Howse, who designed the Micro-blackdeath and the Dark Interpreter which we have used extensively in Isn'tses performances. Great sounding and highly original instruments with esoteric and alchemical concepts behind them.
We've been doing a lot of research towards the design of our synth for Fort Process and some interesting responses to our debut blog post. We were honoured to get some input from father of circuitbending Q. Reed Ghazala who suggests possibilities of water-controlled synthesis:
Our friend Hannah helpfully suggested that we look at Thomas Henry's 'Mega Percussive Synthesizer'. The theory page about this synth has a wealth of useful ideas including the following:
This is very relevant to our concepts for the circuit since we will be using an AM radio chip as a noise source and intend to evoke sounds inspired by the Fort including gunshots and the ocean.
Radio was very important during the world wars when Newhaven Fort was an active military site so we have been looking for inspiration at wartime radios. The rugged and often improvised DIY construction of these devices is reminiscent of the aesthetic of our own noise instruments. Below is a collage of interesting things we found on radio devices and some of our video hardware imagery.
After looking at arial views of Newhaven Fort and this tunnel video I was interested in the shards of light cast in the dark tunnel and have done some rough sketches of artwork for the PCB. We are limited with the amount of colours so may end up with textured patterns, see below.
- Drawings by Lisa McKendrick
We've modified the diagram to show our idea for having touch control pads and a diagram of the chip we are wanting to use:
We are designing a synth in the form of Newhaven Fort as part of Fort Process, a sound art and installation event on 22 September 2018. This mysterious place with it's tunnels and history of two world wars has inspired some curiosity in us. The birds eye view of the site prompted ideas for a synth which we will be documenting in this blog. Below is our initial diagram which gives an idea of the shape.
The synth will have a radio receiver chip (schematic above). We've tried this chip out on the breadboard (see below). Notice how the black component (variable resistor) resembles the gun emplacement !
I'm particularly interested in the relationship to the coast, it's function for guarding the land and it now being a dysfunctional site but a historical place to visit and a space for art. Below is a picture of the coast next to the site. We are designing artwork for the synth and will work with this concept for our drawings.