Showing posts with label CV. Show all posts
Showing posts with label CV. Show all posts

Tuesday, January 10, 2017

Doepfer A-135-4A/B/C Voltage Controlled Performance Mixer Modules Announced


The A-135-4A and B prototypes on display
at the Amsterdam Dance Event in
October 2016
In a previous blogpost I was rather excited about my own new A-138p/o Performance mixer combo.
I bought i just right before I knew that Doepfer was working on a voltage controlled version of this module...

On first impression, the new A-135-4A Voltage Controlled Performance Mixer looks quite the same as the non-cv-controllable A-138p Performance Mixer, only with extra LEDs for displaying the incoming CV voltages for all parameters (except Gain).

Module A-135-4B is the CV-input module, where 16 different control voltages can alter 16 parameters on the A-135-4A Mixer... The modules must be connected via an int 20pin ribbon-cable.

Module A-135-4C is a four-fold envelope follower with adjustable attack and release time for each channel.
The main function of the module is to derive four envelopes from the A-135-4A audio input signals. These voltages can be used to control parameters of the main module A-135-4A via the CV input module A-135-4B2. Typical applications are ducking (e.i. the signal of one channel is used to mute another channel more or less), as well as compressor and expander functions.

A-135-4A/B/C VC Performance mixer prototype
with the A-138o Output module
A-135-4B CV Inputs Module close-up
The modules of the A-135-4 series can be combined with the (non voltage controlled) mixer modules A-138o/p so that these can be used as output module for the A-135-4A. A-135-4A and A-138p can be connected together to the same A-138o to obtain e.g. four fully voltage controlled channels (A-135-4A) and four manually controlled channels (A-138p).

This combo will probably available before spring of this year.

Source:
Preliminary info via http://www.doepfer.de/A1354.htm

Thursday, March 21, 2013

MAQ16/3 FracRak Breakout Box

MAQ 16/3 FracRak breakout panels
Not every-one finds it practical that the Doepfer MAQ16/3 Sequencer has all its connections on the backside of the module.
Especially when you change your setup a lot, you don't want to climb behind your 19"-rack to change patch-cables every time.

Of course there are always people who have figured out a solution for this.

This MAQ breakout panel that i found in an old Matrixsynth post came with a pair of custom made FracRak breakout panels to bring the MIDI jacks and the 1/8" Voltage Control and Gate jacks to the front of your FracRak panel for easy patching.
These would have fit perfectly next to your Paia modules for example.
It also had the necessary cables to connect to these panels from the back of the MAQ16/3.

Sideview of theMAQ 16/3 FracRak
breakout panels
According to the maker these panels were not cheap to put together. (Try pricing the 2 MIDI panel mount barrels and even the 6 panel mount 1/8" barrels)

Theoretically it is possible to make such breakout panels for a Eurorack system.
The CV and Gate outputs would fit easily on one of those 8HP wide pre-drilled blank panels (A-180-style) that Doepfer sells as spare parts. 
You can even put in a few extra switches for your own maximized customization experience. Your limit is your imagination.

Personally, I have long CV (red coded cables) and Gate (blue) wires coming out of my MAQ16/3 that come into my Eurorack system through multiple A-180 Multiples modules, but i can see the benefits of this module.
It might be worth investigating the possibilities of a Eurorack breakout panel a little more for a future blogpost.

Friday, February 01, 2013

Magnetic Table CV-Controller by Jon Sonnenberg

One of the most impressive alternative DIY-controllers i've seen this year is probably this next one.
This Magnetic Table CV-controller is made by Jon Sonnenberg, who has been creating music and been obsessed with electronic music for most of his life.

The design is based on a magnetic pendulum toy;
" The toy consisted of a dangling string with a magnet on the end of it; then it hovered over magnets on a table that either repelled or attracted the string magnet; the stringed magnet then maneuvers around in crazy patterns due to the position of the table magnets.

There are 2 control voltage outputs for this device; one for the X axis, and one for the Y. 
 They vary from 0 to 5 volts. These can be used to change any parameter in a synthesizer or effects system to make interesting sounds. 
 For instance, the X axis could control the pitch of an oscillator, while the Y axis could control the volume. Another example could be the X axis controls a delay time, while the Y axis controls the feedback of the delay unit
Closeup of the upside-down potentiometer-joystick   
 A third example (and a little more abstract) is to have the X axis control the length of a sequence pattern, and the Y axis control the tempo of the sequence.

One interesting thing about using the magnetic table to control sound is that when the pendulum passes over a magnet with a pole that attracts the pendulum, it overshoots a bit, then swing back toward the magnet and overshoots again, continuing to oscillate in a damped, simple harmonic motion. 
 If the magnet is stronger (you can use larger magnets or stack them to make them have a stronger attraction or repulsion), then this oscillation is faster."

Video: The Magnetic Table: A CV controller for Modular Synthesizers

" Here is a demonstration of a CV controller that I built. It is a simple pendulum with a magnet at the end.
The magnets on the table can be moved and can either repel or attract the pendulum.
More information can be found at www.artoftravelogue.com or more specifically here: http://artoftravelogue.blogspot.com/2012/02/magnetic-table-cv-controller.html "

Wednesday, January 18, 2012

The Doepfer Mogli and Gesture Control

In 1993 Doepfer presented the Mogli MIDI Data Glove Controller, an alternative controller device that was based on a Nintendo Power Glove controller.
It had traditional NES controller buttons on the forearm as well as a program button and buttons labeled 0-9.

The complete Mogli set with Power Glove,
receivers,  Mogli interface box and adapters
There were two ultrasonic speakers (transmitters) in the glove and you had to put three ultrasonic microphones (receivers) around your TV monitor.
The ultrasonic speakers took turns transmitting a short burst (a few pulses) of 40 kHz sound and the system measured the time it took for the sound to reach the microphones.
A triangulation calculation was performed to determine the X, Y, Z location of each of the two speakers, which specified the yaw and roll of the hand.
It could also sense the bend of the individual fingers, the only dimension it couldn't calculate was the pitch of the hand, since the hand can pitch without moving the location of the two ultrasonic speakers.

The Power Glove was originally released in 1989 and was in general a critical and commercial failure.
Partly because of the lack of accuracy and the availability of games (for it's original use with the NES)

The Mogli interface box, Power Glove and adapters
In 1993 Doepfer introduced an external box that could receive the glove's data and convert it into MIDI signals.
The name Mogli stands for 'Midi Output GLove Interface'
The original Mogli interface box was equipped with MIDI in and MIDI out, and it had a red 3-digit LED display.
The display was needed to program the unit (i.e.to assign different function to the fingers, to the X/Y/Z coordinates, to the rotating angle and so on).

After a calibrating procedure the glove could be used in different controller modes.
The 'Virtual Play' mode was maybe the most attractive mode, in which could make you play a virtual keyboard in the free space.
In Direct Mode you could assign any movement to any MIDI controller, other modes were Gesture Mode (converting sign-language to MIDI controllers) Vector Mode (position sensing only) and Manipulation Mode (for manipulating incoming MIDI with the glove).

Although i am not the world's greatest electronics-guy i do have a feeling that the original Mogli converter box could be easily transformed into a version that sends Control Voltage and/or Gate signals.
Original Nintendo Power Glove
If you can find one, it will probably just work just fine with one of Doepfer's MIDI-to-CV modules, but you might not get the most out of all the glove's many functions.

The price of the system was 598 DM (i.e. about 300 Euro) for the ready built unit including a Nintendo power glove.
The kit version was 448 DM (i.e. about 225 Euro) incl. Nintendo power glove.
The control box only (without the glove) was 398 DM (i.e, about 200 Euro)
A kit version of the box was also available for just 258 DM (i.e. about 130 Euro)

The unit was available from March 93 until December 1995, but Doepfer had to stop the production because the Nintendo Power Glove was no longer available.
Around 350 units were made in total.
Interesting fact is that the Mogli was also used by Kraftwerk (on 'Pocket Calculator' and 'Music Non Stop') during their concert at the Brucknerhaus in Linz/Austria on the occasion of the ARS Electronica Festival for Art, Technology and Society in 1993.

Okay, i admit that the technology of the Power Glove might be outdated by now, but the idea of controlling sounds/patches with the move of your hand will always stay an interesting subject.
Roland is famous for its D-Beam technology since 1998.
The A-178 Theremin Control Voltage module (or the discontinued A-179 Light Controlled Voltage Source) definitely do not offer all the functionality of a glove like this.

However, i do think we will see some kind of gesture-control-trend coming up this year with the recently announced Kinect motion sensing input device by Microsoft, that was already available for the X-Box platform but that will soon be available for the Windows platform too.
I wonder how soon the first interesting gesture-controlled modular synth-video's will pop up on YouTube...

Find the Mogli's user-manual (in German language only) HERE
Please let me know if you have an English version, or else check the start of my translation project (work in progress).

* Many thanks to Dieter Doepfer for the additional info
Pictures by Gaiana via http://www.synthforum.nl/

Video by studentsmusic added March 1st, 2017:
Doepfer MOGLI Midi Glove (Rare - Vintage)

Saturday, August 13, 2011

CV / Gate Cable Length

A few times I've been asked about how patch-cable lengths ( of CV and/or Gate signals ) can affect signal strength.
I found a few interesting posts in the Yahoo Doepfer Usergroup that might make things a bit clear to you.

First of all;
Gate cables even longer than 10 meters usually are no problem.
Although a gate signal might get slightly weaker when you use extremely long cables, the (simple) gate signal will often stay strong enough to trigger your modules.
CV-Cables of this length may have a slight loss depending on the electrical characteristics of the input and the output.
There are ways to measure it,  but it is very difficult to judge whether a not completely clean octave tracking is caused by long cables.
Real loss of signal quality starts with asymmetric audio cables at such a length, and you have always to keep in mind that electromagnetic and electrostatic influences (hum and sizzle) can affect longer cables more than shorter cables.

" From a theoretical point of view (for anyone interested) the key things are output and input impedance, cable capacitance and resistance.
If you take a relatively standard low-cost coax cable of say 380pF/m and 128 Ohms/km this will not cause any noticeable loss in audio top-end from a 1k Ohm output impedance until you exceed 20m or so but you are more likely to get increased noise and interference.

From a CV point of view the cable resistance is a more important parameter (if your CV is controlling VCOs that is) but even 20m is only 2.6 Ohms so this can be ignored compared to the high input impedance of most VCO CV inputs; again long lengths are more prone to pickup so 50Hz mains can modulate the CV.
( you may also experience hum loops by just connecting gear together that is powered from different power outlets across the room ). " *

( * thanks to Tony Steventon from Synovatron for the 2nd half of this post )

Thursday, November 25, 2010

Volts per Octave

The Volts-per-Octave standard luckily turned out to be a quite good one.
A lot of (early) synthesizers manufacturers adapted this standard, 'invented' and popularized by Bob Moog.

Best known manufacturers of early products using the 1V/Oct standard are Roland, Moog, Sequential Circuits, Oberheim and ARP. The big benefit of standards like these is inter-compatibility between products of different manufacturers. It allowes them to communicate better.

The V/Oct standard was wider adapted as other standards, like for example Yamaha and Korg's Hertz-per-Volt standard, that  represented an octave of pitch by doubling the voltage. 
A few synths that use the Hz/V standard are:
Korg: 770, 900-PS Preset, M-500 Micro Preset, M-500SP Micro Preset, Mini Korg, MS-10, MS-20, MS-50, Synthe-Bass, X-911
Yamaha: CS5, CS10, CS15, CS15D, CS20M, CS30
Moog: Taurus I Bass Pedals
Paia: 2720, 4700 Series


The Hz/V standard was used before the log converter was used in VCO's and is essentially linear control as can be found on various signal generators and function generators like those used by the BBC Radiophonic Workshop before they got a VCS3*. There are/were solutions available that convert from  Hz/Volt to V/Oct and vice-versa.  ( like the Korg MS-02 ).

No wonder that the A-100 system uses the V/Oct. standard. You can easily synchronize your system with almost any (old) machine that you have lying around, and most MIDI-to-CV converters use the same standard too.

For example i love using the CV (and Gate) output of my Roland TB-303 to control my A-100 system. The signal arrives at my system via a  A-180 2x4 multiple, so i have 3 copies of both signals available at any time.
Sometimes i use the CV slightly detuned for an interesting effect, sometimes i put it through a voltage inverter first, something that doesn't work out with all your 303-lines because of tuning.

The Gate output (trigger) of the TB-303 can be sent through a delay for some more interesting echo-like effects.
There are so many possibilities for your other gear to communicate with your A-100 with the 1 V/Oct standard... just go ahead and try... and amaze yourself.

*thanks to Tony Steventon for additional info