Friday, March 30, 2012

Filters VII: A-106-1 Xtreme Lowpass/Highpass Filter

The Doepfer A-106-1 Xtreme Filter was built as a kind of Korg MS20 filter clone.
The famous original MS20 included two filters: a 12 dB lowpass and a 6dB high pass filter connected in series both with a very special design.
On the A-106 product page Doepfer writes: " The A-106-1 is definitely not the right choice for "moogish" and "civilized" sounds but for extreme, exceptional and experimental sounds - this is why we call the module "X-Filter"... "

Doepfer found a way to use the same circuit simultaneously as lowpass and highpass for 2 different audio signals (a bit similar to the A-101-1 Steiner Vactrol filter that has even different audio inputs available, but with the special MS20 circuit).
For this two separate audio inputs for lowpass(LP) and highpass (HP) with separate level controls are available.
The sockets are normalled, so the signal applied to the LP input is available for the HP input too provided that no plug is inserted into the HP input socket.

The level control of the HP input is realized as a polarized input. This means that the signal can be added with the same polarity (+ range) or opposite polarity (- range) compared to the LP input.
This feature enables notch (+) and bandpass (-) filter functions too.

A lot of audio-examples can be found HERE
and on Andreas Krebs' blog

As you will hear in the demo's this is a very nice sounding filter with a distinctive sound.
It can sound very squelchy and dirty, and still also quite smooth...
If you are looking for a do-it-all filter, this might be the one you are looking for.
It is not my favorite filter, but i still rate it at 7/10...

Hans Richter - Rhythmus 23 - Figur 10 - KABELTON

" ...just a test for something bigger... but i like it though.the sound was made with benjolin (rob hordijk and joker nies) and doepfer a-106-1."
Uploaded by Kabelton

Tuesday, March 27, 2012

Doepfer A-189 Bit Crusher Video's by Raul Pena

Raul Pena's video's hardly need any introduction... enjoy!

Video 1: Doepfer A189-1 VBM Voltage Controlled Bit Modifier Basics

" Video outlining the basic features of the Doepfer A189-1 VBM, Voltage Controlled Bit Modifier.Sound and Video by Raul Pena. Next Video: Doepfer A189-1 VBM, Voltage Controlled Bit Modifier-Bit Crushing Demo."

Video 2: Doepfer A189-1 VC Bit Modifier-Bit Crushing

" Demonstration of the bit crushing capabilities of the Doepfer A 189-1 VBM Voltage Controlled Bit Modifier.
Next Video: Demonstrates of the sample rate modifications of the Doepfer A 189-1 VBM Voltage Controlled Bit Modifier on audio Music Track "Texas" by Merryman, used with permission from James Merryman. Available on iTunes.Sound and Video by Raul Pena."

More video's after the break >

Saturday, March 24, 2012

MusikMesse 2012 Dark Energy II and A-157 News and Pictures

The Dark Energy II prototype with
Dieter in the background
As promised a few pictures from the Doepfer goodies at the Alex4 booth from the MusikMesse this year.

The most interesting Doepfer product on exhibit was by far the new Dark Energy II, that looks surprisingly the same as the Dark Energy I.
The DE II will be available this summer.
Check the specifications of the DE II HERE.

Dieter also had a pleasant announcement that the CEM3394 will probably be fabricated again (but it's not certain when they will be available), so there is a possibility that the Dark Energy (I) will also return once those chips arrive...

A closer look at the Dark Energy II

The A-157 (or 'Mini Schaltwerk') Trigger
Sequencer prototype

The A-157 (or 'Mini Schaltwerk') that was on display again didn't look much different than what we saw at NAMM 2010.
Doepfer could however confirm that this module will probably available around june 2012.
I haven't had a chance to talk to Doepfer about it, but i do hope they will switch the layout; inputs on the left and outputs on the right, but that is just a personal preference.

You can watch a short interview with Dieter Doepfer (in German) and some sound-examples of the new DE II by De:Bug Magazin Musikelektronik  HERE
...and another video of the big Doepfer modular in the Alex4 booth by SessionMusikTV (also in German) HERE

*Pictures exclusively made for PatchPierre by @cymatics, check out his music and blog at and

Wednesday, March 21, 2012

MusikMesse 2012 - Alex4 Booth

This year you will find Doepfer products at the MusikMesse (in Frankfurt/ Germany), that started today, in hall 5.1 at booth D86 of their new distribution partner Alex4.

Alex4 is Doepfer's latest partner that aims to "collect regular products and innovations from smallest manufacturers in Europe, the USA or elsewhere to promote and sell them with specialized retail partners over europe fulfilling all european regulations while trying best to go a „green“ way wherever this could be possible."

They also distribute other (small) analog synthesizer brands like Alyseum, Cwejman, Flame, Kenton, Manikin, MFB, MIDI Solutions, Moon Modular, OTO Machines, Sherman SND, Studio Electronics, Vermona and WMD, so they have a very exciting booth at the MusikMesse

Dark Energy II working prototype,
as shown at MusikMesse 2012
A big A-100-System is on exhibit, and the first working prototype of the Dark Energy II is shown at the booth.
Dieter Doepfer was also there today to tell more about their latest products.
Besides the Dark Energy redesign you could also see the A-157 Trigger Sequencer (or so-called 'Mini Schaltwerk') again, although it is still the same version that was shown 2 years ago at NAMM 2010.
The current state of the A-157 is that the new pcb with 8x16 buttons and LEDs is already made and that Doepfer is about to develop the controller board. There is no release date available yet.

Other newsworthy bit was that the Dark Energy 1 will probably return, because the chipmaker that made the CEM3394 chip has promised to start making those chips again. No (re-)release date yet, but i personally don't expect the return of the DE1 this year...

Most of Doepfer's OEM products, the USB/Midi-to-CV/Sync interfaces and the master keyboards were also shown, and loads of other cool hardware from the other brands.

MusikMesse still lasts until March 24...
More info at

Many thanks to 'special reporter' at MusikMesse:

Saturday, March 17, 2012

Early Kraftwerk Modification by Doepfer

You might know that Doepfer can also do customizing and special design jobs for their clients (see HERE), but they must have looked up strange when they got a telephone-call from Dusseldorf in the late 80's..

It was Florian Schneider from Kraftwerk, calling if Doepfer could help them out retrofitting a miniature keyboard with MIDI.
Florian would use this keyboard later to trigger a sampler, and used it with Kraftwerk live for the Pocket Calculator song.
Schneider had to come back a few times to München for this project, and that is when the good relations started between Doepfer and Kraftwerk.

From that time on they worked together on various projects like the MAQ 16/3 sequencer, the MOGLI, the A-100 vocoder and some others.

Since then Doepfer even dares to advertise some products with the 'designed in cooperation with KRAFTWERK' tagline, but "...we shall not exaggerate that", according to Dieter...

KEYS Magazine 12/97 - Picture by: Petra Schrambömer

Wednesday, March 14, 2012

Dark Energy II Specifications Announced

From the Doepfer website:

The Dark Energy (I) has to be discontinued because an important electronic part (CEM3394) is no longer available. (Read more on that HERE)
We are working on the redesign of the Dark Energy at full speed.
The new Dark Energy II will look like the Dark Energy I at first sight.
Only the function of some controls and switches will differ from the Dark Energy I.

Dark Energy (I) picture by Marc Weerts
from the band 
These are the most important differences between Dark Energy I and II:

- 12dB multimode filter with lowpass, notch, highpass and bandpass (instead of 24dB lowpass of Dark Energy I)
- the previous LM control of the filter becomes the filter type control (continuous crossfade lowpass - notch highpass - bandpass)
- the LM function of the filter is no longer available
- the waveform switch is used to select between saw and clipped/distorted saw (in the center position the saw is off)
- the basic waveform of the VCO is saw (not triangle like the Dark Energy I).
- because of the pure analog circuit and the temperature control it takes about 30 minutes until the VCO is in tune.
- the VCA has a exponential scale (not the combined linear/exponential scale of Dark Energy I)

All other functions will remain unchanged.
Even the price will be the same (currently Euro 428).
The Dark Energy II will be probably available summer 2012.

Doepfer hopes to have a (working?) prototype ready for the MusikMesse in Germany, which starts next week.

Tuesday, March 13, 2012

Video: Doepfer Sequence

Another nice A-100 Video, found on Vimeo is simply called Doepfer Sequence
It features a Dark Time sequencer controlling a large A-100 system and a Dark Energy, plus some other equipment.

Original link
Uploaded by Mark Angel

Saturday, March 10, 2012

Modifying the A-124 Wasp Filter a Little More

I don't know why i didn't come up with this idea earlier, but here is a short follow-up to my earlier self-oscillation modification post for the A-124 WASP filter ( original post can be found HERE )

The (mini-) modification consists of adding a switch to toggle between self-oscillation on/off modes.
To do this i had to use an extra 4 HP wide blank panel because there isn't enough space left on the A-124's front-panel to add a switch.
This is not my first 'expansion module',
i  made one earlier for my A-127 Triple Resonance Filter

I did this modification in less than an hour; i carefully drilled a 6 mm. hole in a new 4HP blank panel, desoldered one side of the resistor that i added earlier and connected that one to the new switch.
Another piece of wire connects the other side of the switch back to the original position of where the resistor was connected.

I am very happy with the result, i can now manually switch, turn the resonance-knob up to self-oscillation and simply switch back to the original mode again...

Thanks to Tony Steventon from Synovatron for the project review

Thursday, March 08, 2012

A-114 Ring Modulator Video's by Raul Pena

The next module in the wonderful video tutorial series by Raul Pena is the A-114 Ring Modulator.
Sit back, relax and enjoy!

Video 1: Ring Modulation of Basic Waveforms with Doepfer A114 Ring Mod

" A look at the Doepfer A 114 Ring Mod. Basic Waveforms are used to explore timbres created. Sound and Video by Raul Pena."

Video 2: More Ring Modulation with Doepfer A114 Ring Mod

" Second in the Ring Modulation series. Using a random melody as a sound source timbres are explored further. Sound and Video by Raul Pena."

Video 3: Further Modulations in Ring Modulation with Doepfer A114

" Third installment of the Ring Modulation Series. This video explores how using modulation can change a Ring Modulation Sound. Sound and Video by Raul Pena."

Wednesday, March 07, 2012

Doepfer GMX-1

In 1992 Doepfer released their version of a General MIDI (GM)-compatible MIDI Expander, the GMX-1.
It was Doepfer's attempt to offer a fairly cheap alternative to the popular SoundblastersLAPC's and cheap GM-compatible modules like the Roland SC-7.
The GMX-1 was (based on) a Dream mainboard - you will also find this module as Dream GMX-1 mentioned in old magazines - Future Music rated it 86/100 in issue 4, page 41 )

It was a simple grey box, with only an on/off switch, a volume slider, a mini-jack headphone output and an LED that visualized incoming MIDI signals on the front.
On the back it had 3 MIDI connectors (In, Out and Thru), stereo audio-outputs (cinch) and a 9 Volts adapter input.
Beside that, it also had a nine-pin RS-232-C port that enabled the unit to be connected to a serial port without the need for a MIDI expansion on your computer.
With this port you could hook it up to almost any PC, Commodore Amiga or Apple Macintosh, and it even came with MS Windows drivers and 2 MS-DOS programs that could play back MIDI-files.

The sounds (158 instruments, 47 Sound-effects and 92 percussive sounds) were based on PCM (Pulse Code Modulation) and Algorithmic Synthesis, sampled at 16-bit / 44.1 kHz , and could not be altered.
You could control a few things like volume, pan, velocity, after-touch, modulation and pitch-bend, but no chorus, reverb or other effects.
The Doepfer GMX-1 only had 20-voice polyphony, so it did not fully match the (24-voice) GM standard, but beyond that it was completely GM-compatible.
Besides General MIDI the module also offered an MT-32-mode, that could emulate the (classic 1987) Roland MT-32 module settings.

It sounded decent, but not too impressive, but what would you expect for the price...
Reports say it didn't sound awful and that it actually had some good sounds too, like the pizzicato strings and percussive sounds like vibraphone, marimba, music box and harmonica...
But if you'd put your GMX-1 audio through one of your own FX processors it already sounded a lot better.

Price at the time was 649 DM > around 330 Euro's
Only 250 units were sold through Doepfer, but Zone Distribution in Britain has probably distributed at least a same amount through England and perhaps even more worldwide.

Sunday, March 04, 2012

Video: Charlie Chaplin Through a Doepfer Vocoder

As one of my earliest Quick Tips i suggested to test your Vocoder with recorded spoken word.
In that way you don't have to hold a microphone or constantly keep an eye your audio-levels.
The audio-example that went with that post wasn't that special, but here's another short but nice demonstration, uploaded by YouTube user WorksLimited.

Video: Charlie Chaplin through a Doepfer modular A-100 Vocoder
"Charlie Chaplin speech from The Great Dictator, slowed down about 10% and run through a Doepfer Vocoder. The results compare very favorably to units like the Synton and Sennheiser (in my humble opinion)."

Uploaded by WorksLimited

Thursday, March 01, 2012

DD-System StringPhaser

Look what popped up on eBay this week, a very rare StringPhaser module by a company named 'dd system' ?

This module was one of Doepfer's earliest synthesizer modules, made for the German Formant modular synthesizer, more than 30 years ago according to Dieter.

There were some expansion modules for the Formant available (only as kits) from Doepfer's early company and they were labelled "dd -system".

In the late 70s / early 80s Doepfer made several modules , among them were the System Timer with a master clock and different clock dividing factors, clock/reset polarities and clock/reset levels,
an External Input/Envelope Follower similar to A-119, a Frequency Divider similar to A-115, a Graphic VCO with high speed VCO, a VCLFO, a 12dB VCF with VC Resonance, a VU module (with LED bar), VC phasing I (with FETs), VC phasing II (with LDRs and lamp, similar to the compact phasing), Analog Sequencer 2x16 steps, Polyphonic CV/Gate keyboard, 4-Fold Band Pass with LDRs, and a Digital Sequencer with external RAM cards for 1024 or 2048 note memory (each of the 2102 RAM circuits had 1 kbit at that time!).

From eBay:
" It uses a 3 phase LFO which drives 3 separate phase shift cards (see pictures).
The module has separate 'fb.' and 'mod' controls and 'control' and 'ext. ust' sockets for each of the 3 phasers, and has controls for 'f1', 'f2', 'mixt' and 'ampl'. There are also 5 LEDs and sockets for output and input signals.
Finally there are two switches which are labelled 'ser.' and 'parallel'.

This is a vintage item and has some marks and scratches on the front panel.
The module is believed to be complete, but I've never tested or used the unit.
The previous owner indicated that the unit worked, but that the LFO rate was rather high however I have not confirmed this."

Doepfer replied that he still has a scan of the old StringPhaser document available.
The words are only in German (written by typewriter), the schematics still as a pencil drawing.

More pictures at:,
Thanks for the tip @ZoeBlade