Paper Synth Workshop Announcement & PS401 3:1 Clipping Mixer Details

See this previous post for a video.

Details on the 401 and workshop:

"Paper Synth 401 is a three channel mixer with built in diode clipping for each channel. Saturation is a classic way to get more character out of synthesized sounds. Sometimes it is also needed to ad some edginess to waveforms in order to give some gripping surface to, for example resonant filters.

The sound of the clipping is not like super harsh guitar pedal kind of distortion, instead it adds color and harmonics to the sound to make it more interesting, especially when the clipped signals are mixed together.

Features:
Each of the 3 channels has a separate volume control knob. Far left hand side is silence, middle of the turn is 0db, same volume as signal coming in. If the signal coming in is a eurorack standard 10Vpp, the mixer channel starts to clip after turning the knob right from the middle. Each channel offers a hefty 6db of clipping, so even if the signal coming in, is quieter than 10Vpp, it will get loud enough to start clipping.

The module can also be used as a normal clean mixer, if the channel knobs are kept below the middle point.

All the channels sum into a channel with separate volume control, allowing 6 db of clean gain when needed. A trimmable clip led is attached to the output of the main channel, normally trimmed to light up at 10Vpp.

Three Clip Mix comes with a standard eurorack power connector, but also supports +-15V systems with small modifications.

A non drilled diy aluminium faceplate is also handed at the workshop. We have a possibility to drill the faceplates in our workshop after the electronics have been built.

In the workshop we will build the PS411-EnvAmp. We learn the basics principles how the attack/release envelope generator works and how the optocoupler controlled VCA. And certainly we learn how to use the PS411 - EnvAmp.

All the tool and materials will be provided. The workshop will be held in English and German.

24. September 2017 - 12pm to 7pm
*Studio A.Pussinen & W.Spahn*
Gerichtstr. 12-13
Aufgang 5
Berlin Wedding (S-Bahn Humboldhain)
Costs: 70€ incl. undrilled Faceplate

Registration: postwolfgang-spahn.de

http://workshop.dernulleffekt.de/doku.php?id=paper-synth-401clipmixer_sept2017:details

PS401 1:3 ClipMix eurorack module demonstration

Published on Sep 12, 2017 Antti Pussinen

"A quick demonstration of three to one clipping mixer eurorack synth module. Part of Paper Synthesizer workshop series by Antti Pussinen & Wolfgang Spahn

http://paperpcb.dernulleffekt.de/doku..."

"Paper Synthesizer is a modular environment where one can pick the desired building blocks and builds ones own sound generator of choice. A way to sculpt electricity into waveforms.
Paper Synthesizer is a collaborstion of Antti Pussinen und Wolfgang Spahn."

Module list as of this post:
PS100 - Hard-Sync Oscillator
PS110 - Voltage Controlled Oscillator
PS110 - Wave Converter
PS201 - MIDI to CV
PS202 - MIDI-Duino
PS301 - Diode Wavefolder
PS401 - Clip Mixer
PS411 - EnvAmp (Attack/Release Envelope Generator & Opto-VCA)
PS808 - Kick Drum Board
PS000 - Power-Supply
Calibration Keyboard for PS110
DC-DC 5Vto2x12V Converter Board
USB to FFC Power Connector

New Paper Synth PS-301 Wavefolder Demonstration & Upcoming Workshop

Published on Nov 13, 2015 Antti Pussinen

"Paper Synth PS-301 Diode Wavefolder demonstration video for Paper Synthesizer workshop series by Antti Pussinen & Wolfgang Spahn

The input waveform is saw wave.

www.dernulleffekt.de
www.anttipussinen.net
www.wolfgang-spahn.de"

Additional details including info on the upcoming workshop:

"In this episode of paper synthesizer workshop, we are building a diode wavefolder, that sounds a bit like a resonant filter, but has a very unique sound.

PS301 Diode Wavefolder is a dynamic waveform processor module, that changes the color and the overtones of a sound, while keeping the same base note. The design is originally Jürgen Haible's take on “Serge Wave Multiplier, middle section”. Yves Usson of YuSynth added an exponential VCA to the design, making voltage control possible, and we modified the circuit further to fit our design requirements.

The module takes in a 10VPP sine, triangle or saw wave and folds this waveform back into itself up to 7 times at the crossover point of the wave.The effect sounds a kind of mix of frequency modulation and mid resonance filtering.

The Controls Include 'CV attenuation', 'Fold Range' (which can also be contolled with 0-5v control voltage) and 'Fold Amount' which changes the amount of folds. Inputs and outputs conform to eurorack standards of 10Vpp, and it runs on eurorack +-12v power supply, and even with +15v power supply from Frack Rack or MOTM synthesizer systems.

ll the tools and materials will be provided.

The faceplate is not included!

The workshop will be held in German and English.

Material and further informations:

http://paperpcb.dernulleffekt.de/doku.php?id=paper_synth%3Aps301_wavefolder

The costs are 60,00€ for the materials.
Please register at: post@wolfgang-spahn.de
The workshop will be held at: Mülhauserstr. 6. Hofgebäude 1. OG

A Workshop by Antti Pussinen & Wolfgang Spahn"

Some details from Paper Synth:

"Ps301 Diode Wavefolder is a dynamic waveform processor module, that changes the color and the overtones of a sound, while keeping the same base note. The design is originally Jürgen Haible's take on “Serge Wave Multiplier, middle section”. Yves Usson of YuSynth added an exponential VCA to the design, making voltage control possible, and we modified the circuit further to fit our design requirements.

The module takes in a 10Vpp sine, triangle or saw wave and folds this waveform back into itself up to 7 times at the crossover point of the wave.The effect sounds a kind of mix of frequency modulation and mid resonance filtering.

The Controls Include “CV attenuation”, “Fold Range” (which can also be contolled with 0-5v control voltage) and 'Fold Amount' which changes the amount of folds. Inputs and outputs conform to eurorack standards of 10Vpp, and it runs on eurorack +-12v power supply, and even with +15v power supply from Frack Rack or MOTM synthesizer systems.

Theory of operation

A PS-301 Wavefolder adds overtones to a waveform, a bit like a distortion unit or a resonant filter. But instead of clipping or ringing, when the waveform peak goes over a certain limit, it folds back and creates a new odd harmonic component. Jürgen Haible had a really good explanation of the process on his site, and since its impossible to know how long the legacy site is kept up, i copy it here:

'A string of diodes is driven with the amplified and level shifted input signal. After each diode there is a “tap” with a resistor that will contribute positive or negative to the output of a two-opamp subtracting amplifier. There are two virtual GND nodes for these summing and subtracting operation. By feeding these virtual GND nodes alternately from the taps of the diode string, you can have the output voltage increased when one diode drop voltage is reached, and have the output voltage decreased again when the next diode in row starts conducting. The number of valleys and peaks is only determined by the length of the diode string, and not by the number of opamps. It turned out that choosing equal resistor values results in an almost regular pattern of the voltage transfer function.'"

Paper-Synthesizer Workshop Set for 24 Okt in Berlin

"*Paper-Synthesizer 201 - MIDI to Control Voltage*

by Antti Pussinen and Wolfgang Spahn

In the next installment of Paper Synthesizer workshops, we build a duophonic Midi to Control Voltage converter. The module fits in to Eurorack format, or can be built as a separate interface box. The converter talks with both USBmidi and normal Midi via midi cable.

UsbMidi/Midi to CV converter is the interface that lets other computers, synthesizers and controllers integrate into the modular synthesizer world. While an old standard, Midi keeps its place as the universal data connector in synthesizer world, as well as for other creative controllers ranging from vj and dj controllers, to custom diy button banks, and media artworks.

Control voltage is the analog old school version of midi, where change in voltage means a change in pitch or some other parameter. One instrument is represented as a Volt/Octave output changing the pitch, Gate output telling if the note is on or off, and velocity output, changing the dynamics of the sound.

Our midi to cv offers two of such instruments, with additional midi clock to clock output, and two midi cc to cv output.

Our midi to vc is a open source, arduino based, open hardware project.

The converter offers:
- 2 x 1V/Oct CV Out
- 2 x Gate Out
- 2 x CV Out (velocity)
- 1 x Clock Out
- 2 x Assignable Midi CC Out

It is powered over standard Eurorack power connector (+12V,-12V). A 12V powered box is also possible with adding an dc-dc converter in the box.

The Circuit is built around an Arduino Pro Micro controller, and a two channel precision digital-to-analog converter. In the workshop we go through the circuit of the module, build, test and trim a working module and look a bit into to the code.

All the tools and materials will be provided.\\
The faceplate is not included!\\
The workshop will be held in German and English.\\

====================================================================================
http://workshop.dernulleffekt.de/doku.php?id=paper-synth-201midi-cv_okt2015:details
====================================================================================

Oktober 24. 2015, 11am – 5pm
Werkstatt Berlin
Mülhauserstr. 6. Hofgebäude 1. OG, 10405 Berlin
Costs: 60,00€
Registration: postwolfgang-spahn.de"