Doepfer A-106-1 Xtreme Filter Tutorials by Raul Pena

Raul Pena is back with a new video tutorial series, this time all about the A-106-1 Xtreme Filter.

Here are the first two, of four... 

Video 1: Doepfer A106-1 Xtreme Filter Basics

" A brief description of the features and functions of the Doepfer A106-1 Xtreme filter.
This filter is similar to the filter in the Korg MS20 but has its own unique character. Sound and Video by Raul Pena."

Video 2: Doepfer A1061 Xtreme Lowpass/Highpass Filter Audio Demonstration

"A look at an audio demonstration of the basic features of the Doepfer A106-1 Xtreme Lowpass/Highpass Filter. Sound and Video by Raul Pena."

Video 3: Doepfer A106-1 Xtreme Lowpass/Highpass Filter Modulation and Resonance Part One

" Audio Demonstration of Modulation and using the resonance insert of the Doepfer A106-1 Xtreme Lowpass/Highpass Filter. Sound and Video by Raul Pena."

Video 4:
Doepfer A106 Xtreme Lowpass/Highpass Filter Modulation and Resonance Part Two

" Part Two of an Audio Demonstration of Modulation and using the resonance insert of the Doepfer A106-1 Xtreme Lowpass/Highpass Filter. Sound and Video by Raul Pena."

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

Doepfer Usergroup Poll: Voltage Controlled Slope Module

Recently Dieter Doepfer ordered a new poll in the Doepfer A-100 Usergroup.
It looks like he is seriously considering a 'Serge Voltage Controlled Slope' -inspired A-100 module.
If there is enough positive feedback it will be manufactured with the license of the copyright owners of the Serge module ( and it may also have the additions that Ken stone has designed).
Because of the license fee, the module's price will be a bit higher than standard A-100 modules.

Bananalogue Serge VCS PCB

In the early 1970s, Serge Tcherepnin developed the Positive Slew and Negative Slew modules for the original Serge synthesizer.
In time these merged into the classic Dual Universal Slope Generator.(Vimeo link with video)

For example;
The Serge VCS module, (re-)released in conjunction with bananalogue.com was/is an extremely versatile control voltage generator and audio source.
The Bananalogue VCS and CGS75 are both an adaptation of Serge's original circuit with a few new features.
At first glance it seems to be a VC slew limiter but after a closer look you can discover a very versatile module which can be used as a VC-LFO, VCO, AR-envelope, VCF, envelope follower, waveshaper, subharmonic and a trigger delay.

That's nine functions in one module!
It is not sure which functions the Doepfer module will have, but i guess they will try to get the most out of it.

So, the question in the Usergroup is:
" Would you buy a Doepfer A100 'Serge Voltage Controlled Slope' inspired module? "

The poll will remain open for one month, until 19th of December.
Voting is possible at http://launch.groups.yahoo.com/group/Doepfer_a100/surveys?id=13160415 (for Usergroup members)

Find more info at:
http://web.archive.org/web/20080224013413/www.bananalogue.com/vcs.html
For those interested in the theory of operation, I recommend Tim Stinchcombe's page on this subject.

Doepfer MCV-24 Battery Replacement

Zoë Blade's partner Nina Richards has made an interesting short video demonstrating how to replace the Doepfer MCV-24's internal battery.

Video: Doepfer MCV-24 battery replacement

" Nina's short guide to replacing the internal battery of a Doepfer MCV-24"

Uploaded by Zoë Blade

The following Doepfer devices are (or have been) equipped with a rechargeable battery like this for memory backup:
2.4V rechargeable battery: LMK3/LMK3+
3.6V rechargeable battery, grid 10 x 20 mm.: used in d3c, MCV24, A-112 VC Sampler /Wavetable Oscillator, Schaltwerk and Regelwerk.

Find more info on Doepfer batteries at http://patchpierre.blogspot.nl/2011/09/quick-tip-vii-battery-check.html

Eurorack String and Bow Interface by Peter Speer

As most of you know i have a special interest in alternative controllers and modules.
Earlier this year i posted the Guitar-module for example (can be found HERE)
Although there is not very much innovation in the Eurorack space lately, there are still enough DIY-ers with interesting ideas.

Check out Peter Speer's eurorack String and Bow interface for example.
It consists of a hollow laser cut MDF enclosure, with a guitar string pulled across two zither pins and a contact mic underneath (connected to the front jack).

The bow is homemade (2x4 + horsehair).

The video shows a nice demonstration.

" Pressure Points and the Wogglebug's Stepped Out (triggered by the Pressure Points) are controlling the frequency on the DPO, as well as the pitch shift on the Echophon.

The envelope out from an A-119 is opening the low pass gate on the output and controlling the modulation index on the DPO."

Video: Euro bow interface prototype

Check out Peter's 'Leisure Cove' blog at http://theshamblers.blogspot.com
And subscribe to his videos via Vimeo: http://vimeo.com/53649008

Avoiding Hum From Power Supplies

If you are buying a second-hand rack, or if you already have a Doepfer modular rack with a cheap alternative (non-Doepfer) power supply you should be aware of how to avoid the (minor) transformer hum that cheap PSUs generate.

In the area near those power supplies (bottom right) no modules should be assembled that are sensitive to transformer hum.
Doepfer recommends to assemble only control voltage modules in this area (e.g. LFO, ADSR, trigger delay, clock divider/sequencer, sequencer, slew limiter, MIDI interfaces and so on)
,but no audio modules (VCO, VCF, VCA, VCP, frequency shifter, ring modulator, spring reverb and so on)
Also don't put the A-178 Theremin modules near the power supply.

Doepfer Power Supply I ( PSU I )

This matters for some of the cheap alternative non-Doepfer power supplies, and for the old Doepfer versions with PSU I 
For new A-100G3/G6 cases (with original PSU II) this does not apply. 

Find out how to distinguish the old transformer (PSU I) from the new version (PSU II) at http://patchpierre.blogspot.nl/2012/07/doepfer-power-supplies.html

More info at http://www.doepfer.de/a100p_e.htm#A100P6

A-143-9 Demo by Hawklord2112

Video: A-143-9 Demo

" Simple runthrough of the Doepfer A143-9 VCQLFO"

Uploaded by hawklord2112
Twitter: https://twitter.com/hawklord2112

Doepfer A-117 Digital Noise/808 Source Tutorials by Raul Pena

Yay!
Raul Pena is back with a brand new series, this time all about the Doepfer A-117 Digital Noise/808 Source.

Here is part one, the rest will be added here when they are published (every thursday).

Video 1: Doepfer A117 DNG Basics and Percussion
" Brief Description and Demonstration of the Doepfer A117 Digital Noise, Random Clock and 808 source. Demonstrations of how to create percussion sounds with this module.Sound and Video by Raul Pena."

Video 2: Doepfer A117 Playable Noise and Special FX

" Demonstration of "playable" noise using the Doepfer A-117 DNG. There is also a short demonstration of a Special Effect from the manual for the A-117. Sound and Video by Raul Pena."

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