Doepfer A-167 Comparator Tutorials by Raul Pena

Time for a new Raul Pena tutorial video series.

This time all about the A-167 Analog Comparator module.

Here are the first 3 episodes... i will add new ones every Thursday.

Video 1: Doepfer A-167 Basics

" Description of the Basic Features of the Doepfer A167 Comparator. Sound and Audio by Raul Pena. Sound Demonstration begins in next segment."

Video 2: Doepfer A-167 Offset and Outputs Part One

" A closer look at the output and offset options on the Doepfer A-167 Comparator. Part One of two. Sound and Video by Raul Pena."

Video 3: Doepfer A-167 Offset and Outputs Part Two

" A closer look at the output and offset options on the Doepfer A167 Comparator. This is Part Two of Two. Includes Oscillocope views of waveforms using the Dave Jones Design O'Tool. Sound and Video by Raul Pena."

Video 4: Doepfer A-167 Offset and Free ADSR Part One

" A continued exploration of the Doepfer A167 Comparator. Includes sound examples of Offset and Oscilloscope views. Free Running ADSR example found in next video."

Video 5: Doepfer A-167 Offset and Free ADSR Part Two.

"Part Two of the Doepfer A167 Offset and Free ADSR segment. A continued exploration of the Doepfer A167 Comparator. Includes sound examples of Offset and Oscilloscope views. Free Running ADSR example found in next video. 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 A-197-2 / Velleman VPS10 Oscilloscope Kit

In the early days of the A-100, Doepfer also sold the A-197-2 LCD Oscilloscope Front Panel Kit.

This kit is no longer available, and was not a module manufactured by Doepfer but only a 34HP wide front panel kit to mount the one-channel Velleman Panelscope VPS10 LCD Oscilloscope into an A-100 frame.

The kit consisted of the plain front panel (punched for VPS10, without printing), an A-180 Multiples PC board (mounted crosswise below the scope) and all wires necessary to connect the VPS10 to the A-100 bus (power supply) and the A-180 board (signal input). 

A-197-2 Kit with Velleman VPS10 Oscilloscope
installed plus manual and mounting screws

The connecting lines between the sockets were made with black, waterproof felt pen. 

A little bit of mechanical skills and soldering was necessary to put this all together. 

Three wires had to be soldered to the VPS10 (GND, +12V, signal). 

One hole had to be drilled into the plastic case of the VPS10 for the passage of the wires, and the VPS10 had to be mounted to the front panel with 4 screws and nuts. 

A detailed mounting and soldering description was added to the panel kit. 

A-197-2 Kit with Velleman VPS10
Oscilloscope installed

No special measuring cable (BNC - 3.5 mm jack) was necessary as the four right sockets were internally connected to the VPS BNC input (the BNC input was connected to the right four sockets of the A-180 board) . 

The four left sockets built a second multiple without connection to the VPS10 (same as A-180).

It was also possible to run the VPS10 with an external power supply to save the "high quality" current/voltage of the A-100 bus. 

The VPS10 did not require an exactly adjusted and highly stabilized supply voltage.

Back-side of the A-197-2 Kit with Velleman VPS10
Oscilloscope installed

So... Why did Doepfer offer only the front panel kit ?
Doepfer mentioned on their website: " We do not get a better price for the VPS10 than a normal end user but have to take on the warranty and to calculate the dealers rebate into the final price.
I.e. we have to add at least the dealers rebate and the handling charges to the VPS10 price to obtain a zero profit !
This would extremely increase the price of the module and we think that this is not in the sense of the customers."

You can find the full description and support files for the Vellemann VPS10 HERE
The assembly and wiring manual is available for download from the Doepfer website: A197_2_man.pdf

The price of the A-197-2 was 40 Euro (only for the front panel kit, the VPS10 had to be ordered seperately by the customer e.g. from an electronic shop for almost 200 Euros)

Remark: We are not responsible for the features of the VPS10. 

Mounting/wiring the VPS10 may affect the warranty. 

Pictures via MATRIXSYNTH

RMS No.2 - A Simple Self Generating Patch

I'm usually not a big fan of self generating patches, but here's a nice one.
Plain and simple, slightly dark...

Uploaded by Simon Pott, who says he is new to the world of the modular synthesizer, opened a Vimeo channel yesterday and already uploaded two fine modular videos.
(subscribe at http://vimeo.com/randommodularsnippets)

RMS No.2 - A Simple Self Generating Patch from Random Modular Snippets on Vimeo.
" Featuring:- Doepfer A-110, A-114, A-124, A-143-1, A-143-4 a few utility modules and a Strymon El-Capistan."

Follow Simon Pott on Twitter @SpoiltVictorian

A-171-2 Voltage Controlled Slew Limiter II Announced

Great news again this morning from the Doepfer Yahoo Usergroup.

The A-171-2 Voltage Controlled Slew Limiter II will be Doepfer's next new module with a lot of additional features beyond a simple slew limiter.

A-171-2 Prototype

It's mostly a licensed copy of Ken Stones VCS which is in turn based on the Serge VCS. (from the POLL earlier, remember?)
Dieter announced that negotiations with Serge and Ken Stone are nearly finished, and that they decided to publish the preliminary info page about the planned module on their website: www.doepfer.de/a1712.htm

The main features:
- Manual control of the Slew-Up time
- CV control of the Slew-Up time with polarizer
- Switch for linear/exponential shape of the rising section of the response curve
- Manual control of the Slew-Down time
- CV control of the Slew-Down time with polarizer
- Switch for linear/exponential shape of the falling section of the response curve
- CV Up and CV Down sockets are normalled
- Signal input (the "to-be-slewed" signal)
- Trigger input
- V/Oct input
- End output
- Cyle on/off (when "on" the End output is internally connected to the Trigger Input)
- Output
- LED display

Doepfer also mentioned that they will add some features so that 3-position switches can be used (e.g. log/lin/exp instead of log/lin only and two different cycle modes), but these decisions depend upon the results with the first prototype which he expects in January 2013.

Modular Wild Presents...

Besides his excellent video tutorials and his recent 12 days of modular series, Raul Pena also seems to have time for other analog-video-projects.

He just began a new show called Modular Wild. 

He already released 6 videos there, but one segment that may interest most readers of this blog is probably the one with Doepfer Modules. 

Its a live narrated patching example with about 12U Doepfer modules only.

Video: Modular Wild Presents...Patch it-Frequency Modulation

" Patch It. A segment with a medium to large format modular system, with minimal planning to create a complex patch. Sound and Video by Raul Pena. © 2012 Raul Pena"

Check out all 6 videos (and subscribe) at http://www.youtube.com/modularwild

Twelve Days of Modular 2012 by Raul Pena

Just like last year, Raul Pena is also treating us this year with a new "12 days of Modular" series.
A nice extra series of 12 different short scenes from the Modular World of Raul's World of Synths.

12 Days of Modular 2012 - Day 1 - Ring Modulation

" Day 1: A look at Ring Modulation. Video series of 12 different scenes from the Modular World of Raul's World of Synths. Sound and Video by Raul Pena. © Raul Pena 2012"

12 Days of Modular 2012 - Day 2 - Sample and Hold
" Day 2: A look at Sample and Hold.Video series of 12 different scenes from the Modular World of Raul's World of Synths. Sound and Video by Raul Pena. © Raul Pena 2012"

12 days of Modular 2012 - Day 3 - Track and Hold

" Day 3: A look at Track and Hold.Video series of 12 different scenes from the Modular World of Raul's World of Synths. Sound and Video by Raul Pena. © Raul Pena 2012"

Random Video: Random Melody #121227

I found this one on a new YouTube channel today,
a nice random sequence on a large eurorack synthesizer with mainly Doepfer modules.
Very cool...
The channel promises "Electronic Synthetic Music, Bleeps & Noise.", and i'm already looking forward to more videos.

Video: Random Melody #121227

" Late night random melody patch."

Uploaded by AsteroidKillerMusic

A-136 Pre-amp Modification

I discovered another nice light-weight DIY-project on the Doepfer DIY-page.

Locating the R2 resistor

It seems that the A-136 Distortion/Waveshaper module contains an internal pre-amplifier that is used to amplify the input signal by about 3.5 before it is processed by the A-136.
Especially for low level audio signals (e.g. output from a VCF) this is useful.

But for all signals with a level beyond ~ 7V this causes clipping before the internal processing takes place. 

Especially for the processing of LFOs or unfiltered VCOs this may cause a problem.

The wiring, additional pictures
on the PatchPierre Facebook page

To totally bypass the internal pre-amplifier, resistor R2 can be removed (e.g. by pinching off).

R2 is the resistor in the upper third of the pcb which is very close to the rear edge.
When R2 is removed the amplification of the internal pre-amplifier becomes "1" (which means that it does no longer amplify).

Finished modified A-136 

Because i love to keep myself busy (I'm slightly ADD-ish), i decided to add a switch to the module, so i can switch between pre-amplifier on and off modes.
It looked like an easy project, so... what could go wrong? ;-)

Besides the front-panel it was a pretty easy job;
I desoldered one side of the R2 resistor, bent it over towards the switch, and wired it with black wire.
After that i soldered another wire (red) from the switch to the hole where R2 used to be. Easy as that.

Now i can manually switch the internal amplifier on and off when required.
The clipping did annoy me at times and now i prevent that and try the un-amplified signal with alternate settings*.
it's not a groundbreaking project, but a nice extra.

* In addition one has to pay attention that the knob positions may vary a bit from the front panel printing because of mechanical tolerances of the potentiometers and knobs (i.e. "0" is not always exactly the neutral position for "A", "+A" or "-A")

The modifications described on this site will most likely void any warranty and, if not done carefully, can damage the circuit board, IC chips, and faceplates.
PatchPierre can not be held responsible for any damage.

How NOT to Modify

The rail is still visible through the
new hole i drilled

Okay... sometimes you have to learn the hard way.

I made a slight mistake while drilling a new hole in a front panel for my latest DIY-project.
(blogpost will follow soon)

Although i knew there was not a lot space where i had to drill, i did not calculate that the rail would still be visible.

Hardly visible, but i had to scrape almost
one mm. off the module's PCB

I am glad that i didn't have to put a mini jack connector but only a switch there, but that didn't even fit here.
Okay, maybe I should have drilled a smaller hole in the first place.

My bad... but still very annoying.
On the other side of the hole there's the module's PCB, so i couldn't put the switch higher without also modifying the PCB board.

Luckily i could solve the problem with an extra large ring.
It has not trned out to be my most successful modification.
More info on what i was working on will follow later this week.

Finished switch, with extra large ring

Sadly i also damaged the front-panel a little bit (bottom left and under the D from Doepfer)

I should be more careful next time, and take a little bit more time for my modifications... 

Make a plan first... and work step-by-step.

That would spare me a lot of trouble.

New Doepfer Announcements

Doepfer released preliminary information about two new modules.

The A-190-8 is a MIDI/USB to Sync interface.
Basically this module divides the incoming MIDI or USB clock messages into smaller steps.
You could see it as a modular version of the MSY2 MIDI-to-SYNC Converter that was announced in December last year, but with multiple simultaneous outputs and added USB support.
Funny that i already posted my idea for a module like this in late 2010 (Read that blogpost HERE)

A-190-8 Prototype 1

The main application of the module is the control of clocked A-100 modules like sequencers, sequencer controllers, trigger divider, trigger sequencer and similar units, but also to trigger/reset LFO's, envelope generators and more.

The A-190-8 will have 10 available outputs which are not yet fixed. 

Preliminary info can be found HERE, and if the users think other combinations of clocks or start/stop/reset outputs would be better, Doepfer can change that because the outputs are generated by the firmware of the processor.

Read some of the user suggestions at the Doepfer Yahoo Usergroup.

Doepfer left out the usual DIN SYNC socket because to create that you only need clock and start/stop on two pins of the DIN socket. 

If there are sufficient inquiries Doepfer may offer a special cable with two 3.5 jack plugs on one side and a DIN plug on the other. 

(For example to synchronize a TB-303)

A-180 Multiples and
a 2 HP blindplate,
the size of
the new A-180-2

For early in 2013 also a slim version of the A-180 Multiples module is planned.

This will be called A-180-2 and will be half the size of a regular A-180.

Because of the only 2 HP width nuts cannot be used to mount the pc board by means of the socket nuts at the front panel. 

Instead of that the PC board is mounted by screws and spacers at the front panel.(pic)

Personally i don't think i want one of those in my system because of how a nut-less module looks, but i can imagine there are people who applaud space-saving modules like this.

There were also a few other announcements/updates:
In December the A-192-2 (Dual CV/Gate-to-USB/Midi interface) will be available and even the hardware of the Polyphonic CV/Gate interface A-190-5 is ready.
"Christian (Assall) is about to program the firmware. But it takes longer than expected  and so the A-190-5 will be available early in 2013."

Special thanks to Bakis Sirros in the Doepfer Usergroup for sharing parts of this info.
Bakis can be found via multiple ways, support him and his band(s) to help the Greece economy a bit:

www.parallel-worlds-music.com
www.facebook.com/pages/Parallel-Worlds/192093934136476
www.myspace.com/interconnectedmusic
www.myspace.com/memorygeist
www.DiN.org.uk
www.vu-us.com