Doepfer A-125 Voltage Controlled Phase Shifter Video Tutorials by Raul Pena

Raul Pena just posted a new tutorial video in his Doepfer Series, this time all about the Doepfer A-125 Voltage Controlled Phase Shifter.

Here's part one, enjoy!

Video : Doepfer A125 Voltage Controlled Phase Shifter Basics

" A short overview of the basic features and functions of the Doepfer A125 Voltage Controlled Phase Shifter. Sound and Video by Raul Pena. "

Video 2: Doepfer A125 Phase Shifter Audio Demonstration Part One

" A short audio demonstration of the basic functions of the Doepfer A125 Phase Shifter. Includes oscilloscope views. Sound and Video by Raul Pena."

Video 3: Doepfer A125 Phase Shifter Audio Demonstration Part Two

" A continued exploration of the Doepfer A125 Phase Shifter. More sound examples of the Phase Shifter. Sound and Video by Raul Pena."

Video 4: Doepfer A125 VC Phase Shifter Modulation Part One

" Further exploring with the Doepfer A125 VC Phase Shifter. Examples of basic modulation with an envelope and LFO.Sound and Video by Raul Pena."

Video 5: Doepfer A125 VC Phase Shifter Modulation Part Two

" Further exploring with the Doepfer A125 VC Phase Shifter. Examples with Random, Noise and sample and hold.Sound and Video by Raul Pena."

New videos in this series will be added to this post weekly on Thursdays.

Check out Raul's latest survey at http://www.surveymonkey.com/s/K3Z9PVF

Other places to find Raul's World of Synths on the Web:

raulsworldofsynths on YouTube

raulsworldofsynths on Vimeo

raulsworldofsynths on SoundCloud

raulsworldofsynths at iTunes

raulsworldofsynths at CDBABY

Random Video: Epoch Modular 'Benjolin' with Doepfer A-143-9 and A-135-1 by isvisible

Another nice Eurorack video by isvisible popped up on Vimeo today:

Video: Epoch Modular 'Benjolin' with Doepfer A-143-9 and A-135-1

Epoch Modular 'Benjolin' with Doepfer A-143-9 and A-135-1 from isvisible on Vimeo.
" I wanted to make a video showing off the many facets of the Benjolin, but got carried away with it and only covered a little bit.
There were only three modules used... an Epoch Modular version of the Benjolin (originally designed by Rob Hordijk), and two Doepfer modules, an A-143-9 Quadrature LFO which is modulating the VCA's in the A-135-1 Quad VCA / VC Mixer.
The A-143-9 is in turn being modulated by the Rungler out on the Benjolin.

Four audio channels were taken from the Benjolin and into the Quad VCA.
1 - LPF.
2 - XOR.
3 - HPF
4 - PWM
There was slight panning of the four channels in my mixer (Output 1 slight left, to output 4 slight right) then recorded with no external effects or any additional modulation."

For more info on the Benjolin by Epoch Modular please visit epochmodular.net/benjolin.html

Find music by isvisible at:

isvisible.co.uk

isvisible.bandcamp.com

Modular Wild Presents Maths Minute - Maths as Logic/Voltage Inverter

Raul Pena just released a new video today. this one is an unreleased MATHS Minute, featuring the MakeNoise Maths module...

Video: Modular Wild Presents Maths Minute-Maths as Logic/Voltage Inverter

"A timed exploration of the Maths as a Logic/Voltage Inverter patch found in the Make Noise MATHS manual.Sound and Video by Raul Pena.

Special thanks to Tony Rolando at Make Noise.© 2013 Raul Pena "

Other places to find Raul's World of Synths on the Web:

raulsworldofsynths on YouTube

raulsworldofsynths on Vimeo

raulsworldofsynths on SoundCloud

raulsworldofsynths at iTunes

raulsworldofsynths at CDBABY

Find earlier episodes of Math Minute on Raul's YouTube page HERE (Playlist)

Doepfer A-101-6 Six Stage VC Opto FET Filter/Phaser Announced

Another new module announcement from Doepfer.

" A-101-6 is a new filter module that uses so-called opto FETs to control the filter frequency.

A-101-6 Six Stage Opto FET VCF

Opto FETs are very similar to Vactrols but use light depending field effect transistors (FETs) instead of light depending resistors (LDRs).

A Opto FET is a combination of a light depending FET and a LED (light emitting diode) both put into a small light-proof case.

The advantage compared to vactrols is the much faster response of opto FETs compared to LDRs. 

This allows much faster attack/decay times and even FM effects. 

The disadvantage compared to vactrols is that the FET behaves as a normal Ohm resistor only for small levels. With higher levels the FET begins to distort.

Apart from this the notes mentioned on the Doepfer Vactrol Basics page are valid.

Module A-101-6 is made of six serial 6dB filter stages. The stages can be switched simultaneously to lowpass, highpass or one of two allpass types.
The following schematics show one of the six serial stages in the four possible modes:

A-101-6 Principle Schematics

The variable resistor shown in the schematics corresponds to the opto FET.
The type of filter is selected by two toggle switches or 2 control inputs.
The upper switch selects between lowpass and highpass provided that the lower switch is in the LP/HP position.
When the lower switch in the AP (allpass) position the upper switch is used to select between the two allpass types. Instead of the switches even external control voltages can be used (CV LP/HP, CV Allpass sockets).
For this the toggle switch in question has to be in the left position.

The brightness of the Opto FET LEDs and consequently the filter frequency can be adjusted manually (Frequ. control) and controlled by means of an external control voltage (CV) with attenuator.
The LED at the front panel reflects the LED brightness inside the opto FETs.

The resonance is controlled by the Feedback control up to self oscillation. By means of two trimming potentiometers the maximal feedback can be adjusted separately for LP/HP and allpass mode.
High feedback values can be used mainly in the allpass mode to obtain very extreme self oscillation sounds. Even an external feedback signal can be used instead of the internal feedback connection (FB In socket).

The Mix control is used to pan between the original signal (CCW position) and the effect signal (CW position).
In filter mode (LP/HP) this control is usually set fully CW.
In the allpass modes one obtains phasing sounds at center position or "pure" allpass sound in fully CW position."

Update May 6th 2014:
" thank you for your interest in the planned module.
Because of several suggestions by customers there will be probably some additions (like voltage
controlled dry/wet mix and maybe voltage controlled resonance/feedback).
So it will still take some time until the module is available.
An experienced A-100 user is currently about to try out the prototype (still without the additional voltage controlled features) and we wait for his assessment about the features of the module before we continue.
If the module is back I can do some demos." *source Dieter Doepfer

Release date and price for this module are not yet available.
Source: http://www.doepfer.de/a1016.htm
Read more about Opto-Isolators at http://en.wikipedia.org/wiki/Opto-isolator
and more about Vactrols at http://patchpierre.blogspot.nl/2011/02/vactrol-basics.html

The new Doepfer modules will be shown at #MusikMesse in the booth of their distributor Alex4 in hall 5.1, booth nr. C54

Doepfer A-127 BOM Filter Breakout Module Announced

Doepfer finally announced a few new modules for this year.
The first one is an expander-module for the A-127 Triple Voltage Controlled Resonance Filter, which has always been my favorite Doepfer filter...

Basically they took advantage of all the filter outputs that were already available in the original A-127 module, but not made available on the frontpanel.

I wrote about how i made my own A-127-expansion-board a few years ago in this blog, but this official board takes it to the next level, with even one more filter and separate audio outputs.

A-127 BOM Filter
Breakout Module

" For early summer 2014 the A-127 breakout module is planned.

This expansion module offers these new functions:
- additional notch filter for each sub-unit
- separate outputs for lowpass, highpass, bandpass and notch for each sub-unit
- separate audio input with attenuator for each sub-unit

The breakout module allows the separate use of each of the three A-127 filters.
In addition the filters can be patched parallel or serial.
Especially the serial connection of three notches generates very complex phasing-like structures.
For parallel filter connection the existing mixer of the main module may be used or an external mixer.
For serial connection the filters are patched in the desired sequence at the breakout module.
A jumper is used to define the filter type for each sub-unit for the mix unit of the main module.

Remark:
The breakout module can be used without modification only in combination with the new version of the A-127 (pcb printing "Version 4").
Only the new version has the expansion connector available, that is required to connect the breakout module.
It's also possible to combine the breakout module with older versions of the A-127 (versions 1, 2 and 3) but in this case soldering is required to connect the breakout module to the main module (soldering 4 wires to each filter unit).

We will publish corresponding modification instructions as soon as the breakout module will be available."

You can still find my own A-127 DIY-expander blogposts via http://patchpierre.blogspot.nl/2010/12/modifications-ii-127-triple-resonance.html

Source: http://www.doepfer.de/a127.htm

The new Doepfer modules will be shown at #MusikMesse in the booth of their distributor Alex4 in hall 5.1, booth nr. C54

Update May 23 2014: " The A-127 BOM is already in production and should be available July 2014."

Doepfer Re-Designs Update

The 'old' A-166
Dual Logic Module

No exciting Doepfer announcements for the upcoming MusikMesse (The world's largest trade fair for musical instruments 12-15 March, Frankfurt/Germany) yet, but Dieter Doepfer did update the members of the Doepfer A-100 Usergroup today on a few upcoming module-plans and re-designs.

" So far there is no release date for the A-166-2 available the zero crossing comparator was also mentioned as part of the module.

The inquiries for such a module seem to be very poor.

But I will finish this module anyhow (just for myself) because I need such functions now and then (especially the flipflop)..."

The original
A-114 RingMod

Find more about the A-166-2 features in my blogpost from last November HERE

"...In addition we think about the redesign of some older modules.

Especially we think of new arrangements of some dual modules (Dual Ring Modulator A-114, Dual S&H A-148, Dual Trigger Delay A-162, Dual Slew Limiter A-170, Dual Trigger Modifier A-185 ...) as in many cases e.g. only a single ring modulator or a single Sample & Hold.

This will lead to some new combo modules (e.g. combination of S&H and VC slew limiter in one module) with a more value for money as you do not have to pay for unused second sub-units."

Source: Dieter Doepfer

 - Find a selection of Doepfer products at Musikmesse in Frankfurt from 12th - 15th March, 2014 at the booth of their European distributor Alex 4 in hall 5.1, booth nr C54. -

ADDAC210 Open Heart Surgery, Thoughts and FreqTalk Dreams

ADDAC210 Open Heart Surgery - Eurorack & Arduino Development Board

I'm still stoked about last weeks' ADDAC210 specifications announcement that i just had to write an extra blogpost about it.
At least 5 people already decided to pre-order this new Eurorack and Arduino Development Board, so the module will definitely be taken into production by ADDAC, a Portuguese company that has produced many more other innovative modules (100s Series!)over the last couple of years.

Although the idea is not completely new (see BeavisBoard), this is the first time that it is integrated in a 36HP wide Eurorack module with pre-mounted knobs, switches and mini-jacks.
Reading the comments about the ADDAC210 all over the web, the overall thought of most people seems to be "what can i do with it?"

The BeavisBoard-website has some nice examples that will also be interesting for synth-enthusiasts, but possibilities are almost limitless...

If you're a Eurorack fan, into synth DIY, and familiar with breadboards you instantly see this as an exciting and challenging module.

This must be the ultimate way to design, create and prototype your wildest synth ideas... and it will make bread-boarding so much easier!

The ADDAC210 comes with a 1 meter flat-cable and four 5.5cm. stands, so you can also keep it on your desk outside of your Eurorack while you are working on it.

The breadboards will be screwed to the front panel to allow "pre-patched" breadboards to be interchanged too. 

The knobs and the inputs on the bottom of the module will make designing new Eurorack synths/controllers feel very intuitive.

Now you can start experimenting, you will only have to get your hands on a (classic) cool (synth)-chips or other small electronics and then you can have so much fun with this... 

Expand your project on this breadboard by adding adding your favorite filter circuits and stuff... so exciting...

This module will bring Eurorack-patching to a micro-level with tiny jumper wires, resistors, diodes, microchips and more.

I'm already looking forward to the first creative online video examples...

A few random ideas:

Random spare parts

- experiment with your old chips that were always somewhere hidden on the bottom of your DIY-case

(maybe leftovers from other (old) synths, or old radio-parts)

- You can easily create a great fuzz using a single transistor and diode.

- With an added Arduino shield/board there are multiple sequencing/ timing / mathemetical- related functions that would be possible... (and even sampling !)

- How cool would it be to install various sensors on it? Adding a light-sensor/photo-resistor can turn this into a theremin-like module... but also think of a pressure-, heat-, or... lets say a humidity-sensor or Anemometer (a device used for measuring wind speed (vid)? It might sound weird now, but who knows what voltages you can use and what effect it can have on sound...

- Try to build your own Brian May treble booster; a single medium-gain transistor with low-value caps on the input boost the treble part of the signal. The original used a BC182L transistor but the 2N5087 works just the same. This circuit is very close to the original Dallas Rangemaster. (via the BeavisAudio-site)

- My ultimate wet dream would be (re-)creating something like the FreqTalk (see below) or some kind of Flame Talking Synth-clone (and HERE) with the use of one or two Magnevation SpeakJet (or other) speech-chips.
The FreqTalk is based on an Arduino board and 2 SpeakJet chips and I have a feeling that the ADDAC210 will make a speech synthesis synth like this possible, and probably quite easy too IMO.

Video 1: FreqTalk Introduction

" Narrated introduction to the FreqTalk synthesizer."

Video 2: FreqTalk freestyle demo

" FreqTalk synth playing through AdrenaLinn effects.Cameo appearance by E-Mu PX-7 drum machine.
(c) 2010 Andy Hutson"

In the comments Andy writes:
"... the SpeakJets basically cover 3 octaves (B0 to B3), but since the tuning is integer-based, and musical tuning isn't, many of the notes are slightly sharp or flat, but it's close enough for techno, so to speak. The chips are worth getting...they're a lot of fun to play with in Arduino applications. Easy serial communications, minimal wiring required."

"... It took several weeks of evenings, but I didn't keep track of all the hours. Thankfully for the new model, most of the code was a direct cut-n-paste, and I just have to add code to drive the sequencers and LCD screen. Hope to have it done and new videos posted before the end of the year.
"... I don't see mass producing these anytime soon, but the thought has crossed my mind. If I find the time, I'll post news on this channel. Currently, I am working on a new model...same sounds, but better interface, with an LCD screen and built-in step sequencer... SpeakJet chips are basically triggered via serial messages, but in conjunction with an Arduino, you can wire them up to accept almost any kind of signal to trigger them."

Videos uploaded and comments by lamatronix

I understand that you do have to have a bit of knowledge about electronics and probably about Arduino programming, but this module is ideal for anyone who wants to start realizing their own Eurorack synth or controller.
Still a great module for enthusiastic beginners...
Feel free to leave your ideas/suggestions below in the comments! (I might add more of them to this blogpost later)

Find my earlier ADDAC210 blogpost (with full specifications) at http://patchpierre.blogspot.nl/2014/02/addac210-open-heart-surgery-announced.html
Also keep an eye on the ADDAC210 Open Heart Surgery-thread on MuffWiggler  for the latest updates.

ADDAC210 website: http://www.addacsystem.com/product/addac200-series/addac210