Custom Order: Fotosis No. 007, Noise Generating Synth.

Hello world, its been some months since we have completed anything in the realm of homemade electronics. Basically we have had our world turned upside down lately, I am now living in a whole other country working at a new job and trying to do as much Fotosis related work as possible on my off time when I come back to Lyon on the weekends.

This project was a custom order that challenged us to develop several new systems, most notable a sample and hold circuit and a micro-controller based trigger pulse generating system.

There are too many controls to list individually and descriptions would be difficult because I don't think it would be possible to find similar controls on another system to compare them to. This will probably be the last time I try to make an all in one unit this complex due to the time it took to develop build, test and debug the various circuits and programs that it contains. I feel in the future it would be better to build each of the systems individually and house them in separate enclosures that could be attached to some sort of board that gives them power etc.

Anyway here it is in action Fotosis No. 007...



There are still two more sections to complete, a CV interpretation module that will take in a control voltage and convert it to trigger pulses that can be used with the trigger pulse system and also a rocker pedal that will control the pitch of the oscillators as well as several other functions.

The sound range from more conventional synth noises to full on noise as well as different patterns of beeps and tones created by the trigger pulse generator. It would be the type of instrument ideally suited to someone wishing to create strange little samples for use on their tracks or it could be used live as a bizarre noise generating unit.

So essentially I am not going to go into details regarding the technical elements because there are just too many, so please just bask in the glory of this weird and interesting creation.

-J

For Sale: Fotosis No.003

Good news everyone! We have been very busy the last few weeks working on commissioned work and as a result haven't posted anything on our Etsy shop in a few weeks, until now:-)

This instrument which we have labeled Fotosis No.003 was designed and built by Connie it was the first unit she has designed and built alone and I love it.

It is currently for sale on our Etsy shop.

In terms of functions it is identical to Fotosis No.002 only the housing and layout of the controls is different.

We are selling it for 300 US Dollars which the same price that we sold No.002 but translates into a bit less for us when you convert it into Euro. But due to the fact that we have upgraded our basic design recently and all future units will have extra features and different construction our next models will be priced a bit higher.

Fotosis No.003 is a three in one device. It contains a simple optically controlled synth, a separate noise maker circuit and a passive ring modulator all in one box. There are ten pots, two LDR's, seven toggle switches and two momentary switches all of which control the active circuits and allow you to turn on and off various effects or sections and bypass parts of the device.

This instrument is housed in a thin sided wooden box also purpose built. Most of the wiring is point to point (in a vintage style) to reduce solder board complexity. The instrument is coated in an orange tolex like material and has steel corners and aluminum trimming around the control panel, there is also a leather carry handle on the front.

The sounds produces vary from weird drones to little sequences of chirps, bleeps and beeps and also full on noise.

There are three sections, two oscillators and a ring modulator each oscillator can be used on its own or can be mixed using the ring modulator.

It can be used as an instrument on its own or as an effect that can modulate the sound of other line level devices that are fed into the input of the ring mod.

There is a video of the instrument in action at...





It measures 36 cm long by 22.5 cm wide, the control panel is sloped and is 10 cm at its highest point Fotosis No.003 weighs about 900g.

Features:

Firstly there is a passive ring modulator comprised of three jacks, input, suppressed carrier frequency input and output. There is also a bypass toggle that switches the input straight to the output. But as with most passive ring modulators the inputs and outputs are interchangeable.

Optically controlled LFO producing a pure sine wave, with frequency switching function, low and high pitch switch and a toggle that switches off the optical function allows you to control the oscillator using two pots for when you want very slow non audible sine waves used mainly with the ring modulator as the carrier signal. Just above the main controls there is a volume knob. You can interact with this sections using the two LDR's mounted on the face of the control panel using you hands or other light sources, our favorite is to use flashing bike lights, strobes or torches for weird whining tones and intense beeps.

Next is a strange square wave noise generator that consists of two oscillators interacting with one another. Screaming high pitched tones can be produced as can low fuzz like sounds when the pots are at their max or min positions, in between you find effects similar to a simple two tone sequencer changing relative to one of the pots. There is also a low pass filter and volume control.

We have been playing around with it for a while now and have still have not discovered all the possible sounds you can create. It would be perfect for anyone into Circuit Bending, dronescape music, performance art, noise art installations, DJ's or just musicians who want a device on the side that they can use as a noise wig out machine. It is capable of plenty more subtle sci-fi effects and also when effect units like delay, phase, fuzz or pitch modulating pedals are connected between the device and an amplifier the number of potential sounds you can produce grows.

None of the controls are labeled because they are often quite difficult to describe, but we will be suppling a drawing of the control panel with descriptions relating to the function of each knob and switch to get you started.

Here is a basic run down of the controls:

Oscillator 1 Top of control panel:

High / low pitch toggle switch.
LDR switching on / off.
LDR / potentiometer select.
Kill switch.
Momentary bypass kill switch.
Volume knob.
Sine wave intensity knob.

Oscillator 2 Bottom of control panel:

High / low pitch toggle switch.
Low pass filter setting knob.
Volume knob.
Square wave 1 frequency knob.
Square wave 2 pulse speed knob.
Square wave 1 Square wave 2 mix knob.
Kill switch.
Momentary bypass kill switch.
Oscillator 1 LDR's.

Centre of control panel:

Ring mod. bypass toggle.
Oscillator 1 momentary bypass of kill switch.
Oscillator 2 momentary bypass of kill switch.
Oscillator 1 LDR's.
Power indicator LED.

Rear of unit:

Oscillator 1 1/4" output mono.
Oscillator 2 1/4" output mono.
Ring mod. input 1/4" mono.
Ring mod. carrier input 1/4" mono.
Ring mod. output 1/4" mono.
Power on toggle.
9v dc jack.

Downloads: Where to find all of our sound clips

I thought it would be a good idea to do a short post showing anyone interested where our sound clips can be downloaded. I use an upload service called in.solit.us from which we usually embed mp3's but if you want to download the files feel free to do so they can be found here. We release everything we do under the creative commons 3.0 license so you can remix, reuse and redistribute the files with our blessing.

-J

Custom Order: Fotosis No.004: Now With Extra Knob

We have just finished Fotosis No. 004. Its a hybrid synth /effect unit that combines noise maker, ring modulator and optical theremin. It was a custom job for a friend and includes two new features that were not on the original Fotosis No. 002. There is now an extra oscillator (Extra Knob) on the square wave section and a footswitch so you can bypass the ring mod. as you would with any normal guitar pedal.

The extra knob gives the synth lots of new capabilities and seems to act a bit like a sequencer, generating a variety of interesting beeps and blips that repeat every couple of seconds. Before I would have described it as a simple noise making unit but now with this modification it has become a whole lot more interesting to me. The sound clip below is a short composition I created the other night to demonstrate some of the devices sounds.



We are constantly redesigning and improving our instruments, trying to build devices that we feel are tough enough to last a lifetime and have a sound unique enough to keep any electronic musician happy. Each instrument will be an improvement on the last exhibiting its own visual style is well as new materials and construction techniques.

Improvements to Fotosis No.004 include, tougher case now made from tolex coated 8mm pine and leather carry handle.

Below is another picture of the unit which shows the 25 Way D type connector into which you plug the footswitch.

Design: Fotosis No. 005

Fotosis instrument No. oo5 will be a hybrid guitar / synth, but not 80's keytar style. Actually it will have everything our previous instruments had with a special sort of experimental guitar added to the control panel. That means square wave noise maker section, optical theremin, passive ring modulator and a weird stringed instrument all in one. The picture on the left is my first drawing of the proposed device. I suppose it'll look and play a bit like a lap steel guitar.

The guitar has two rails running parallel to and just below the strings. These allow the player to insert a third bridge at any location they like or place a platform / fretboard under the strings on which the can mount objects to play the instrument as a prepared guitar. There will be two handmade high output pickups (similar to the ones I made for this instrument) located at both bridges. Each pickup will have independent volume control and its own 1/4" mono output to increase the experimentation potential of the device. The instrument can be played into the ring modulator and made to sound nothing like a guitar at all.

We will be starting construction in the next week or so after we catch up on our current orders and will post images of the design and construction process here.

The sound clip below was a test I did a while ago to determine what sounds would be produced by such a device. I simply plucked the strings with one hand and adjusted the controls on the square wave section of Fotosis No. 002 with the other. The embed is a bit slow give it a few seconds to get working but the file can be downloaded here if you still have trouble.



This picture is of the setup used to produce those sounds, notice the chop stick rammed under the strings. This acts as the third bridge.


-J

How-To: Fotosis No. 000 Schematic...

I've decided to post a schematic for an optical theremin / synth that is a simplified version of our first creation, Fotosis No. 001. Its based around the XR2206 function generator which produces the sound (Sine Wave) and the 40106 chip that I use to trigger the LDR switching function on the XR2206. The controls are simple, three pots and three toggle switches. The pots control volume, sine wave intensity and LDR switching speed and the toggles turn LDR switching on / off (S1), (S2) for high and low pitch setting and (S3) which gives you the capability of redirecting the timing resistor pins on the XR2206 chip to some other form of resistance.

You could build a hybrid sequencer / optical theremin using a micro-controller like the Arduino board with a few opto-couplers switching the timing pins through resistors (4N37's work well) or make a noise maker using the spare Hex Schmitt Triggers on the 40106. There are many possibilities. All of the Capacitors are 1uf ceramic (Farnell part number 110-0420) except C4 which is 0.33uf polyester (Farnell part number 116-6040) all resistors are 1/4 Watt. The LDRs are 1M Ohm in total darkness and the whole circuit runs on 9V dc.

A .PDF of the same schematic can be found here.

Here is a more complicated version we built and sold a few weeks ago, the link includes a video so you can get an idea of what sounds you can expect.

Any questions I will answer to the best of my abilities...

For Sale: Fotosis No. 002...

Just posted "Fotosis 002" for sale on ebay.co.uk, you can view the listing here. (This item is now available for purchase at our Etsy Shop) Starting bid is £175 sterling. I so wish I could sell these for less so more people could be in possession of very their own noise machine (because everybody needs a noise machine) but alas components are not free and it took me like four days to build it from scratch so I felt the starting price was as little as I could charge. Anyway still messing around with it trying to get as much playing (Testing) time with it as I can before I have to give it away and I still think its amazing. The picture on above is the development process of Fotosis 002 where I carefully connected various other home made circuits to the half finished device so I could assess nice values for the components that influence the sound before soldering them into place. I like to use different value components in every device even if the devices look the same on the outside in order to give every instrument a unique voice.

Here is a new sound clip I recorded yesterday. Its the voice of Winston Churchill doing the we will fight them on the beaches speech being played from my laptops headphone jack via the ring modulator with oscillator two (The square wave one) being used as the carrier frequency.



Or you can download it directly here.

Bye for now:-)

Fotosis No. 002 Optically Controlled Synth / Ring Mod. / Noise Maker...

We have been very busy the last two weeks deciding on a final design for this instrument which will be our main product from this point forth. The challenge was to create something that was not so complicated it would be really difficult to build or play and not so simple that the person playing it would get bored after an hour or so thinking that they had discovered all the instruments potential. In the end we built "Fotosis No. 002" which is comprised of three sections, optical theremin (Sine wave), noise maker (Square wave) and a passive ring modulator.

The first section is an updated version of our premier instrument "Fotosis No. 001", which was an optically controlled sine wave generator. This section no longer has built in microprocessor controlled effects, I did this to reduce complexity but I have added the ability to bring the sound synthesis chip under the control of two pots instead of the LDR's with the flick of a toggle and I've also added a kill switch and momentary kill bypass button to the output (Thanks Ian for the pointers). This section can be used on its own as an optical theremin or as a drone machine, there are one or two other functions but they would take a while to explain so ill leave them a mystery for now:-)

The second section is a simple enough square wave noise maker that produces nice high and low pitched tones, squeals and fuzz sounds. On its own it can generate quite a few interesting sounds, some scary, some annoying. This section will keep you occupied for a while as a noise maker but its real purpose is to provide the ring modulator with a carrier. Like the first optical section there is a volume pot a kill switch and kill bypass before the output.

In the top of the unit there are five standard audio jacks the one on the far left belongs to the optical section, the jack on the far right is dedicated to the square wave noise maker and the three in the middle concern the ring modulator.

These three jacks (In the middle) from left to right are ring mod. input, carrier input and ring mod output but actually they are interchangeable. Either oscillator optical or noise maker can be used as the carrier that will modulate whatever signal is on the input which can even be from another instrument such as a keyboard, guitar, laptop head phone output, AM radio etc. anything that is at line level can be fed into the ring mod and distorted and made all weird. Passive instruments need to be amplified by some kind of line driver as would be the case for a guitar or bass where an overdrive pedal would be needed to drive the input transformer.

The ring mod. is a passive system as in it uses no power and contains no active components. It is made from two 1:1 ratio CT transformers and four matched germanium diodes. The sound produced is often bell like, sometimes lightly distorted and generally way out weird. You can also bypass the ring mod. section with the flick of a toggle switch so your input signal is untreated. You can have hours of fun modulating oscillator one with oscillator two or vice versa and looking for interesting tracks in your music library to play through it.


The whole unit is housed in a wooden box with a pine frame on the interior, everything is first glued together and then fixed to the pine frame with many many stainless steel screws. The box is coated in a Tolex like material that I found in my local art store to make it look nice. There are also steel corners to protect it from knocks and rubber feet on the bottom so it wont scratch the hell out of you table.

The whole thing runs off a standard nine volt negative tip positive shell PSU, I generally supply a Boss PSA 230 wall wart with each unit sold because I find they are pretty robust and reasonably priced.

It took me about a four day to build this not working full time of course and I've been testing it continuously since I finished and I have yet to find all possible permutations of knob settings.

Ill be putting it up on Ebay pretty soon so if anyone is interested in buying it just let me know before I auction it.

Here are some Youtube clips...



Part 1...
Part 2...

Here are some sound samples. To download, the download button is at the bottom of the page that the download button brings you to if that makes any sense? You'll see:-/





Download audio directly.
Clip 1...
Clip 2...

If you have any more questions regarding this device feel free to contact me ill be more than happy to send you extra sound clips of the unit in action or answer any questions you have relating to it.

For Sale: Optically Controlled Synth / Theremin

John has just completed this antique cased optical theremin and it is currently up for auction on Ebay.

Here are the details:

“This is an optically controlled noise maker (Sound Synthesizer). It comprises of three LDR's that control the sounds produced and the microprocessor controlled effects.

There are three control knobs. The first is for LDR switching speed where the sound synthesis chip alternates between two LDR's, measuring their values producing two different tones depending on the level of light falling on each. This effect creates strange sixties sci-fi sounds. The second knob controls the sine wave intensity which is handy when you apply effects like distortion and fuzz to the signal before amplification. The third knob controls the output volume.

There are several toggle switches on the unit. On the left hand side, the first sets the device either for high or low pitch sounds ranging from low rumbling drones to high pitch chirps andwhines. There is a power switch in the centre to turn the synth on and off, and a switch to select the LDR switching effect. The knobs on the right engage the microprocessor which measures values on the first LDR and does one of two things. The first thing it does is only allow the device to produce sound when a certain level of light has been reached which is useful when you don't want the unit to play itself (Be silent until you interact with it). The second microprocessor controlled effect toggle again sets a threshold which keeps the device silent until a certain level of light has been reached but this time it pulses the sound on and off increasing the speed of the pulses when the level of light on the LDR increases sort of like a built in tremolo effect.

There are three LED's. The centre LED indicates power on and the other two the state of the two microprocessor controlled effects.

The unit is housed in an antique (19th century) handmade French jewelery box stamped with the mark of Pierre Dujardin Paris. I restored the box to make it as robust as possible and left the weird repairs and different layers of paint that had been applied by the many previous owners that give this device an authentic aged and vintage look, sort of like an old piece of lab equipment or a prop from a mad scientists lab.

Various other visual garnishes have been added such as the leather straps that hold the lid open and the foam that lines the inside of the lid.

(the inside is coated in a latex based plastic like preservative and pine sections have been added to the interior corners using epoxy)

This synth/noisemaker-theremin thingy runs off a 9V power supply, I'm including a brand new Boss PSA-230P (Still in box) with the unit.

The output is loud as its at about line level when the sine wave intensity is at max and the volume fully on.

Here is a youtube video of the device in operation with just a bit of reverb added by a Boss DD3.


The unit can be played with your hands or with light sources. A bike light produce the best effects, creating techno-like beats by selecting the flashing settings on the light and by placing them directly over the LDR's. I've recently discovered that by running the unit into an Electro Harmonix Guitar micro-synth, a whole range of other sonic possibilities were presented.

If you require other sound samples I will be more than happy to supply them just email me at johncavanagh(at)gmail.com just replace the (at) with @

NOTE: I will actually ship to Europe and the US if you contact me first so I can figure out postage, just email me and we can discuss postage etc...”

Go to EBay for more pictures.

Our previous projects:
Cardboard Synth, Simple Saw Theremin, Homemade CD Mixes & Cases, Children's Eskimo Pop-Up Book, Paper Lampshades, Etc...

More to come, stay tuned!

- C

Welcome!

We are still setting up this site so make sure to check back for updates. Our soon-to-be developed blog will include our sales information, other traditional and electronic instruments, recycled art projects and various other DIY happenings.

Feel free to contact us by email, info is on your left.

Thanks for coming by, J&C