Wednesday, July 06, 2011

Booktip IX - Analog Synthesis by Reinhart Schmitz


One of the smallest books in my whole BookTip section, but nevertheless a pretty informative one is this 128-page booklet by Reinhard Schmitz.

Analog Synthesis -The Newbie Guide to Synthesizers and Sound-Design  (also available in German) is full of basic info on how synthesis works. Very easy to read, and focused mainly on beginners this is a nice resource for all things synth...

In different chapters the main components of a (modular) synthesizer are explained, accompanied by simple  black/white pictures and graphs. 
The book is completed with an extensive glossary and a pretty nice 39-track audio-CD with audio-examples of the most important analog synthesizers of Moog, Oberheim, ARP and Sequential Circuits, to name but a few.

Some time ago Doepfer used to give this book (or the German version) away for free if you purchased a full Doepfer system. 
Getting it is better than buying it; for such a small book the price ( 36 USD ) is a bit too high IMHO...
Wizoo has quite an extensive collection of other English and German audio/ recording -books too.
You can find the other English books here

ISBN:  978-3-934903-01-2
Publication Date: 1999 by Wizoo Publishing GmbH
More info on this book HERE

Friday, July 01, 2011

Discontinued A-100 Modules

Good things come and good things go...
There are many different reasons for manufacturers to stop producing certain modules.
Sadly for some people, some components of a few Doepfer modules aren't available anymore.
Some of the special circuits ( or IC's) in the modules have become scarce, or not available at all ( like the original knobs ) , and that has been a reason for Doepfer to discontinue the production of some of these modules.

Another reason to stop producing certain modules is because they just don't or didn't sell... maybe just because they are not very useful (anymore) or they disappeared when newer modules appeared with (almost) the same function(s).

Soon a collector's item?
An overview ( updated February 2012 ) :

A-111 High End VCO  As the special circuit CEM3340 used in this module is no longer available the module has to be discontinued.
/ Sale while stocks last.

A-121 Multimode Filter As the special circuit CEM3320 used in this module is no longer available the module has to be discontinued soon.
/ Sale while stocks last (only 20 left in Januari 2012)
Doepfer recommends the A-106-6 XP VCF, that is based on the filter circuit of the Oberheim Xpander, as a replacement module.

...the A-101-9 Universal Vactrol Controller is the latest addition to the running out/ sale while stock lasts list... more info on this later

The A-111-5 Mini Synth Voice (and the Dark Energy) will also be discontinued because of CEM3394 chip running out... Stock is still available.
More info on this HERE

The following Doepfer modules are not available anymore:

A-123 24dB High Pass was discontinued at the time by poor sales, and the special circuit CEM3320 used in this module is no longer available.

...and another one...
A-126 Frequency Shifter Because the special circuit CEM3382 used in the internal quadrature VCO of the A-126 is no longer available Doepfer had stop the production of this module too.
But they are about to plan a succeeding model ( A-126-2 ) without internal VCO. The advantage of this solution is that even frequencies below 50Hz are available for special beat effects based of frequency shifting at low frequencies.

A-138x Mix Expander - Because of the poor inquiries the production of this module had been stopped too.

A-139 Headphone Amplifier, a 2-channel headphone amplifier with 2 audio inputs (3.5 mm jack sockets) and level controls, common loudness/master level control, 2 headphone outputs (stereo 1/4" jack sockets) - no longer available

A-177 External Foot Controller is now replaced by the A-177-2, a more economical replacement with a little less control (without LEDs and without scale controls), but with almost the same functions.

A-179 Light Controlled Voltage Source is also no longer available as the special circuit CEM3320 used in this module is no longer available. That is why this module also had to be discontinued.

A-191 MIDI-to-CV Interface / Shepard Generator no longer available

A-197 Analog Meter no longer available ( i personally never really expected an analog meter to be very useful, and i guess i wasn't the only one )

A-197-2 Oscilloscope kit no longer available -
I am still looking for an affordable oscilloscope though. I was thinking about something like a MFB VD-01 Videoscope, but sadly there's no budget at the moment...

Latest update: A-188-1Y BBD Module (256 stages) is also on sale while stocks last


Curious what chip is inside your synthesizer?
Check http://synthtech.com/cems.html and
http://sequencer.de/synth/index.php/Chips_in_Synthesizers

    Friday, June 24, 2011

    Modifying the A-124 Wasp Filter for self-oscillation

    Out of the box the A-124 Wasp filter can not go into self oscillation, in contrast to most of the other filters in the A-100 system.
    Lucky for us modifying the module for self-oscillation is quite easy;
    Doepfer's DIY page tells us that;

    "Soldering a 10k resistor in parallel to R13 (27k) leads to self-oscillation of the filter at the max. resonance setting of the resonance control."

    Locating the R13 resistor was perhaps the most difficult part of the job. Because the resistors are all soldered on the PCB very tightly it is hard to read what the printing on the board says about the mounted resistors... but i found it!
    Locating the R13 resistor
    R13 is located in the gap between IC1 (CD4069) and IC2 (i.e. the upper CA3080, close to C4/100pF). See picture above.

    I did have a few spare parts lying around, including a 10k resistor. Soldering in parallel in this case was very simple. I did this on the backside of the PCB.
    After locating the correct resistor you can simply solder the new resistor on the other side of it. Not much can go wrong.
    Just be aware that your soldering-iron doesn't overheat or burn your resistor.

    I read mixed reviews of this modification, but you have to remind yourself that the A-124 itself acts kinda unpredictable in the first place, due to the design that "abuses" digital inverters as analog operational amplifiers leading to distortions and other "dirty" effects.

    A post-modification audio demo by Madrayken ( Dene Carter ) can be found HERE

    Tuesday, June 21, 2011

    A-175 Dual Voltage Inverter

    The A-175 (Dual) Voltage Inverter simply does what the name says; it contains 2 separate inverters that invert the voltage of incoming signals; an input of +4 V will be output as -4 V, an input of -3 V will be output as +3 V, and so on.
    Two LEDs give a visual indication of the (positive or negative) output signal for each inverter.

    I use this module a lot, as i blogged before, most of the time both inverters are constantly attached to my A-174-1 Joystick module. I am thinking of buying another one soon, because this module is just so useful.
    I love the fact that each inverter has 2 inputs, so they can be used as a (mini) multiplier.
    In this way you don't have to 'lose' the original signal.

    As input source you can use almost any CV source, not just the ones that produce both positive and negative voltages. 

    A simple LFO will do, and the Joystick and Modulation Wheels are also very handy basic controllers.
    The A-175 manual has some interesting user-examples, including a basic panning patch and a scale/arpeggio-mirroring patch, but again; possibilities are endless, the only limit is your imagination.

    Friday, June 17, 2011

    Quotes IX : Jean-Michel Jarre



    " I think that you have to seriously have fun, or taking serious things in a light way... and obviously for me before all, music is made of fun and pleasure and excitement. "

    Jean-Michel Jarre  Composer, musician, artist, producer

    (from WikiQuotes)

    Saturday, June 11, 2011

    How To Hide an Arpeggiator

    An arpeggiator is a feature available on some synthesizers that automatically steps through a sequence of notes based on an input chord, thus creating an arpeggio.

    One of my biggest personal complaints about the 'original' A-190 MIDI-CV Interface was the fact that the front-plate had the text 'arpeg.' on it while an arpeggiator function wasn't even implemented (and still not) in this module.

    Doepfer recently stated that "...there were plans to add an arpeggiator when the module was designed about 15 years ago. But we found that the processor power is not sufficient to add this feature..."
    He also stated that the new A-190-3 USB/Midi-to-CV module does have an arpeggiator available. ( the A-190-3 is the modular version of the Dark Link and Dark Energy USB/Midi interface, watch an 8-minute video about the Dark Energy's arpeggiator functions below ).

    The same functions should work on the A-190-3 ( and Dark Link ) too, but i haven't had any hands-on time with this module to check and haven't seen much info on the web.
    It does look like a very basic arpeggiator that will be hard to program, only with external MIDI-controller-messages ( like the R2M if i am correct ), but it is a good start.
    I would rather see a more dedicated arpeggiator module from Doepfer, with easy accessible buttons and switches for the different settings and run-modes. Something like the Toppobrillo Quantimator (PDF) or the forthcoming Flame Chord Machine would be nice...

    The weird thing though is that the whole arpeggio function is not mentioned anywhere on the module's web-page while this is such a useful function.
    In fact; it's the first A-100 module that has a (basic) arpeggiator (!)

    Because an A-190-3 manual isn't available yet, you can find a bit more info on how the arpeggiator works in the Dark Link manual ( PDF /page 13)*

    *thanks to Paul Rogalinski for the tip

    Video: Using Doepfer Dark Energy Arpeggiator


    Detailed reference video by Dmitry Shtatnov with Doepfer Dark Energy internal arpeggiator + live song performed using Dark Energy and A-100 modular system.

    Wednesday, June 08, 2011

    Black, The New Silver


    Like it or not; It looks like Doepfer is slowly changing the main colors of their products into the new black and white color-scheme.
    It all started with the Dark Energy synthesizer and the Dark Time sequencer, and recently they changed the case-colors of their USB/MIDI interfaces MSY2, MCV4 and Dark Link.

    The first (and probably only) A-100-related new black thing is Doepfer's Ribbon Controller ( The R2M control box and the manual, not the A-198 module itself )
    As of June 2011 the cases of this Ribbon Controller will be black with white printing instead of the old silver-grey look.

    I like this move towards black from Doepfer because it does make these instruments and boxes look slick(er).
    It is probably cheaper too for them to produce, but i'm not sure of that ( and doesn't really matter to me).

    But what will be next..? Will they also change the A-100's front-plates?
    I guess (and hope) not... that will seriously mess up the overall view in my opinion, although i do like the black and white look from the vintage Moog and Roland modulars.
    Fact is that those modules are far better readable due to the high contrast, but i don't think they should apply this to the older A-100 modules. ( but íf Doepfer ever comes up with a range of specific drum-modules i wouldn't mind them being black and white because this can be seen as a separate (sub-) system... )