Doepfer Dark Energy III Announced

Doepfer announced some interesting new stuff for the upcoming NAMM  exhibition later this week.

(January 25/28 2018, Anaheim, Hall A, booth 10706)

I will post the new A-100 modules in another blogpost, but first the exciting Dark Energy III

Dark Energy III is the successor of the Dark Energy II, a monophonic stand-alone synthesizer with USB and Midi interface. Main differences between II and III are an

improved VCO (no warm-up period, additional triangle waveform, wider frequency range), resettable LFOs, improved ADSR and a lot of internal access points for DIYers.

This will make it easier for DIY-ers to create their own breakout boxes with extra functions, like Organzoner did a while ago... He posted a great video with a step-by-step tutorial on how to expand the capabilities of the Doepfer Dark Energy 2 by adding a breakout box...

The filter of the Dark Energy II has been unchanged.

The sound generation and all modulation sources are still 100% analog, only the USB/Midi interface contains digital components. 

􀂃 VCO:
o Triangle based, 10 octaves frequency range
o Tune control and Octave switch – 1 / 0 / +1 octave
o FM input with selectable source (ADSR / off / LFO1)
o Manual PW control and PWM with selectable source (ADSR / off / LFO2) for rectangle wave
o Waveform switch
o Additional external CV inputs for frequency and pulsewidth of the rectangle
􀂃 VCF:
o 12dB Multimode VCF with continuous mode control (lowpass – notch – highpass - bandpass)
o Manual Frequency control and FM with selectable source (ADSR / off / LFO2)
o Resonance control, up to self oscillation
o Additional external CV and external audio input
􀂃 VCA:
o Linear control scale
o Manual Amplitude control and AM with selectable source (ADSR / off / LFO1)
o Additional external CV input
􀂃 Envelope:
o Improved ADSR type with 3-position range switch
o Additional external gate input
o Control LED
􀂃 LFO:
o Two resettable LFOs (external Reset inputs)
o manual frequency control and 3-position range switches
o Waveform switches triangle/square
o LED controls

More info at http://www.doepfer.de/home_e.htm

Doepfer A-138 On/Off Switches Modification by Philippe Beaubrun

A-138 Mod by
Philippe Beaubrun

Philippe Beaubrun posted a few pictures on Facebook about his small Doepfer A-138 modification.
He added 2 HP wide breakout panels with 4 switches next to the A-138, to turn the individual channels on or off.


The pictures are quite clear, so re-creating this mod will be a piece of cake...

Personally I would prefer my switches on a 4HP wide panel for cosmetic reasons, but this doesn't look too bad.

More pictures HERE

A-110 Tuning Knob Modification

Triggered by a photo by Scott Rogers that popped up on Flickr a few weeks ago, I decided to re-create the A-110 Oscillator modification that he made.
Scott simply added a resistor in parallel with R5 to increase the tune knob range to a bit more than an octave up and down.

Locating R5 on the A-110 VCO

On Scott's blog he writes:
" I’ve already made my first modification to my Doepfer A-110 Oscillators.

For some reason they have set the Tune knob range to only a single tone up or down. 

One thing I do a lot is offset the oscillators by a fifth so this wasn't going to do!

So I contacted Doepfer and they told me (more or less) what to do.
So what I did was this: located resister R5 on the circuit board and added a second resister in parallel with it to reduce it’s value.

Locating R5 on the A-110 VCO
on the other side

I added a 100K resister and this now gives me a range of an octave and a third up and a bit more than an octave down. 

So now it’s a bit more difficult to fine tune, but now I have a huge tuning range that lets me do a lot more! "

The modification is also described in the A-110 service manual on the Doepfer website:
" From the factory the range is about 2 semitones to enable a fine tuning of the VCO.
If you are a bit familiar with soldering you may modify the A-110: shorten R9 (this increase the range about by a factor 3) or reduce the value of R5 (1M).

You may solder e.g. a second resistor in parallel to the existing R5 (1M). The smaller the value of the resistor the higher the range."

A 100K, 5% resistor in paralel with R5

Re-creating this modification was not difficult, after locating the R5 resistor, soldering the 100K, 5% resistor in parallel to it was a piece of cake.

I don't have any test-equipment, but after listening to the result, it changed the range of the tune knob on my A-110 from around 3 or 4 semitones up/down to a little bit over 1 octave /around 15 semitones, so the results seem to vary a little bit per A-110... which probably has to do with different internal potmeter settings on the PCB.

Scott's blogpost: http://www.scottfromcanada.com/wordpress/?p=194

For more info, also read the discussion on Reddit:
http://www.reddit.com/r/modular/comments/1h6zj5/new_to_modular_how_do_i_tune_a_doepfer_a110/

Thanks to Nicholas Keller for additional support, info and links!

The mods described on this site will most likely void any warranty and, if not done carefully, can damage the circuit board, IC chips, and faceplates.

Doepfer A-118 Extra Random Output Modification

A-118 front panel,
secured and ready
for drilling

In preparation for the next #ModularBattle round, i figured out i had to do something to get a little bit more out of my pretty basic set of Doepfer Modules.

I decided to add an extra Random Output to my A-118 Noise/Random Voltage module, which was quite an easy job.

After i removed the knobs and the sockets i could remove the frontpanel of the module.
I mounted it on a flat piece of (old)wood, and secured it with two nails to avoid the frontpanel slipping away.
With a nail and a hammer i punched a small guide-hole for my drill, and drilled an extra hole for the new mini-jack connector.

To protect the front-plate, you can use an adhesive foil or (painter's) masking tape to cover the front, but if you drill very carefully, and don't wipe but blow the aluminium-scrapes off the module you'll be fine.

A-118 extra random output wiring

The new mini-jack connector was one that i ordered from Doepfer earlier (i have a big collection of mini-jack connectors, knobs and switches - they sell them seperately as spare parts) and the connection with the other random output was made with 2 pieces of wire and my soldering-iron.
The connection was as easy as it looks, and it looks like my soldering-skills are (slightly) improving...

Finished module with
extra random output

Don'be afraid for any CV-loss now that the signal has to be distributed over the two Random busses.
Doepfer confirmed to me that "this just works as a mini multiple and doesn't lower the CV"

Now that the modification is done, the module sends 2 similar (controllable) random voltages to both outputs that i can use for all kinds of purposes throughout my modular synthesizer.

For a modification that was done in less than an hour, it is a nice improvement...

The mods described on this site will most likely void any warranty and, if not done carefully, can damage the circuit board, IC chips, and faceplates.

"The rules of fair play do not apply in love and war." John Lyly's 'Euphues' (1578) #ModularBattle

MAQ16/3 On/Off Switch Modification by fixed1t

Seriously... why do some manufacturers still build equipment without a proper on/off switch?

It looks like Malcolm Dixon AKA fixed1t has tackled the problem that a lot of people seem to have with the Doepfer MAQ16/3 Analog Sequencer not having a power switch on the front panel.
He wrote an interesting post about how he added an on/off switch to the frontpanel of his black MAQ16/3 on his new blog ( find blog-post HERE), and he even made an explanatory video with it.

Video: DOEPFER MAQ16/3 Analogue Switch Modification
" The DOEPFER MAQ16/3 Analogue Sequencer has no front panel switch and its been a constant source of hassle having to unplug its Wall-Wart power supply at the back.
Also pulling cables at the back of the rack constantly unplugged it.
I could take it no longer and decided to put a power switch on the front and one which looks like it should be there.

Finished project with nicely aligned on/off switch

The Mod took a few hours to do (safely) but works a treat.
I decided to video it from my phone.
Let me know if you need more details on how to add a switch to your unit.

The music: Angels v Robots I wrote with the MAQ after making the mod."

Check out his myspace at: http://www.myspace.com/fixed1t
Follow him on Twitter: http://Twitter.com/fixed1t
and keep an eye on his new blog at http://fixed1t.blogspot.com

A-128 Modification by Ernst van der Loo

Dutch Sound Designer, Engineer, Composer & Performer Ernst van der Loo posted a few pictures of his latest DIY-project in the Doepfer A-100 Facebook group.

Tools of the trade and lots of wire

The project involved creating 15 individual outputs for his Doepfer A-128 fixed filter bank.

Module A-128 (Fixed Filter Bank) is a filter bank, made up of 15 parallel band pass filters, all with fixed middle frequencies and bandwidth.

Each band pass filter has its own amplitude control knob, with which that frequency band can be attenuated. 

The bandwidth of each of the filters is approximately half an octave.
The signal at the original output of the A-128 contains a mix of all the filters, depending on the position of each one's amplitude control knob.

Finished project 

Ernst used an 8HP blind panel to create the expansion board for his A-128, drilled 15 holes, mounted the mini-jack-connectors and connected them with the correct terminals/outputs on the A-128 PCB board.
There is even the choice between pre-attenuator terminals (fixed volume) or post-attenuator.
You can find the document that shows how to add these single outputs to the filter bank A-128 in THIS PDF (from Doepfer's DIY page)

Ernst commented on the end-result:
 "Not too happy with the alignment of the mini-jacks yet. Maybe I'll need a new drill exercise..."

Maybe he should have saved himself the trouble, because if desired Doepfer can carry out this modification in the factory  (price for blind plate 8HP + 15 sockets + about one hour working time) for about Euro 100 altogether.

Pictures used with kind permission by
 http://www.ernstvanderloo.com

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.

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

Hardcore Modding the A-182-1 Switched Multiples

I must admit i am not a very sophisticated modifier / solderer.

I don't have an electronic background, find it hard to concentrate at times, and i can easily lose my patience when i'm working on stuff.

I am quickly satisfied with the modifications that i do, as long as my projects look good on the outside and are safe (i.e. no loose wires inside that can cause short-circuiting etc.)

A good example of my somewhat rude approach is my A-182-1 Switched Multiples modification.

Originally this module is a simple passive multi-connector similar to the A-180 Multiples module.

In the A-182-1 each socket is equipped with a 3-position switch that allows to connect the corresponding socket to the internal bus #1 (left position), bus #2 (right position) or to turn the socket off (center position).

A-182-1 Modification detail

I wisely decided to split up the A-182-1 into a 2 x 4 Multiplier, like i did with my A-180 because I found this this modification very handy.

I can now use my modified A-182-1 Switched Multiple for quick switching between my keyboard ( via MIDI ) and my A-198 Ribbon Controller.
For this i split up the Multiple in two halves, the upper half controls the Gate, the lower half controls the pitch ( CV )

More info on this HERE

Okay... I know i could have scraped of some of the wires on the PCB to do this modification, but i wasn't completely sure if that would be enough. To be sure that there were no other connections i just took a junior hacksaw and cut the whole PCB in half. 

As this is a passive module (not connected to the busboard) i thought my mod could hardly go wrong with this.

It might be a bit rude perhaps, but it works!

More Blue LEDs

Okay... I haven't had much time to write and post these last weeks because i'm too busy working this summer, but i'm not completely sitting still.

The new blue LEDs that I ordered arrived, so the next few weeks i will only be replacing some red LEDs by blue ones.
It's not the most exiting modification, but it will make my A-100 system more pretty IMHO.
( Info on replacing LEDs HERE )

I do have time to read during my work, and i'm reading a very interesting (Dutch) book called "Onder Stroom" by Jacqueline Oskamp at the moment.
This book tells the story about the history of electronic music in the Netherlands, so expect a book-review of that in the near future.
( The book is slightly related / overlapping  THIS )

I will be back with some more interesting posts in a few weeks... so please stay tuned!

Timing Capacitors of the A-100 System

Okay... I did write a little about the Timing Capacitors of the A-100 modules in my latest post, but i found it so interesting that i thought i should do another short post about this.

Timing Capacitors of the A-118

If you want to modify a module yourself please read this document first: Timing capacitors of A-100 modules.
That document is intended for experienced A-100 users who want to modify the timing range of some modules (e.g. envelope generators, LFOs, slew limiters). 

To lengten the time or period the capacitor value has to be increased and vice versa. The capacitor value is proportional to the time or period (e.g. doubling the capacitor value even doubles the time or period, when the capacitor value is increased tenfold even the time or period increases tenfold). 

By request the time range of delay and/or length can be modified very easily by changing the value of a capacitor, e.g. 200 us...1 s or 20 us ... 100 ms or 2us ... 10ms. That way the module can be used also for audio applications.
If an electrolytic capacitor is used one has to pay attention to the polarity (minus and/or plus sign).

Timing Capacitors of the A-119

Although Doepfer has very clear pictures on their site on where to find the right capacitors i decided to make a library of my own as pictures with info for your comfort.
Here are two already, expect more in the coming next months.

Feel free to use and/or distribute... More promotion for the site is very much appreciated ;-)

The mods described will most likely void any warranty and, if not done carefully, can damage the circuit board, IC chips, and faceplates.

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

 WaspPostMod by Madrayken 

Modifications V : Replacing more LEDs

I am not sure if i should bother you all with every LED i replace, but my first try went so well that i am happy to share my latest update too.

This time i very bravely went for two (2!) LEDs at once. The module i picked for this was the A-166 Dual Logic Module. I thought the 2 inverted trigger output LEDs at the bottom of the front-plate were perfect for this. I don't use these a lot, so the lower 2 LEDs are almost always burning, what also gives a nice effect in the dark.

To reach the soldering-points of the 2 LEDs i had to remove one of the modules boards on the backside.
This was was easy as each board is only fixed with its own 8 sockets. After that i removed the flat connector between the two boards and that created enough access to do my work.

De-soldering the old LEDs was a piece of cake, and the new ones fitted quite easy too.
See my earlier LED replacement post HERE for (safety) remarks, warnings and additional info.

Modifications IV : Replacing LEDs

 Instead of going the easy route by ordering A-100 modules with blue LEDs, i just had to try to do this by myself. Lately you can pre-order modules with blue LEDs installed for a 2 Euro fee per assembled LED, but i don't believe that was possible when i bought my first modules.

It wasn't a very difficult job, perhaps more difficult was choosing which LED i wanted to replace. As always, i try to keep the look of the system as logic as possible, other examples are the colored switches and colored patch-cables.
( also see Color-Coding )
Plus, for my first replacement i wanted to find an LED that was a easily accessible. I found out that the Doepfer boards are so full that many of the LED are in tight spots on the boards.

I'm glad that i had finally found one; the overload LED from my A-119 External Input / Envelope Follower.
Removing the old LED was easy. I bent it out of it's front-plate hole and heated the soldering-points one by one while pulling the LED out softly.
After that i took the new blue LED, bent the 90 degrees angle the same way as the old one and pushed it gently into the A-100's board again. The solder that was left from the old LED was enough to tightly fix the new one.

A few notes:
- You can not use any LED, only use the same ones that Doepfer provides. Always check documentation for more info.
- Due to technical reasons not every red LED can be replaced by a blue one. ( like the Vactrol modules ) Check each module's webpage before you start.
- Don't forget to check the polarity of the LED's ( + / - )
- Blue LED's are actually transparent/white when they are not lit.

Modifications III : A-127 Triple Resonance Filter Expander (part 2)

Hmmm... that went faster as i expected.
My brand new self-made A-127 Expander Module is now almost finished.
( Find part 1 HERE)
The switches are wired too, and the overall look of the module is even better as expected.

I did have some trouble with drilling holes through the aluminium front-plate at first, but it seems i aligned the sockets nice enough with the output sockets of the A-127 itself.
The switches work smoothly and the 'new' 12 dB filters sound sweeeeeet.

I'm very happy with this module, and glad that i went with this option instead of just putting switches on the A-127's front panel.


The wiring of the modules on the backside was quite simple. Red wires were used for switching between the different filter-modes, the blue ones the the audio-multipliers, and yellow ones (not visible in the picture) for the lower switch.
I did the soldering without removing anything from the module, but you might want to remove some components for easier access.

Instead of soldering you can also use small (0.1") wire-sockets at the board's jumper-spots. An example with detailed information of this can be found HERE

Update March 10, 2014
Doepfer announced an official Breakout Module for the A-127,
find out all about it at http://patchpierre.blogspot.nl/2014/03/doepfer-127-bom-filter-breakout-module.html

Modifications II : A-127 Triple Resonance Filter Expander

Now that i finished my first 'real' module-modification i couldn't wait to start with the next project.
At first i wanted to replace a red LED for a blue one on one of my modules myself, but i couldn't decide which module i should pick for this... and i'm still not sure, but that can wait....

Another plan that was in my head from the beginning was the placing of 3 switches on the front-plate of my A-127 Triple Resonance Filter. There are 3 jumpers inside this module that allow the user to switch the filter-type of each of the three channels between Band-Pass (standard) and 12 dB Low-Pass. I have seen some examples on the web of this modification, most of them just with the switches mounted on the A-127 itself, but unexperienced as i am, i was too afraid to damage the front-panel and went for an Expander Module design.

So that is why i am building it into an official 4HP blind-panel that i bought from Doepfer. Each of the three A-127 channels on my expander module design will have a switch to switch the channel's filter-mode and will also provide an extra (linked) audio output.
( mainly to fill up the space, but i aligned these with the A-127's original outputs to make it look more like an official Doepfer module ) .

To complete the expander module i also want to place a switch at the bottom that has the function of the J3 jumper that is inside the A-127 module on the mix circuit-board. This switch can put the module in a mode so that both levels of the filter and the original can be controlled with attenuator 1 ( audio level in )

I am not finished with the project yet, the mounting of the switches and extra outputs is done. Wiring is the next step, i'll write another post on that later this week...
Find Part 2 at http://patchpierre.blogspot.nl/2010/12/modifications-iii-127-triple-resonance.html


Update March 10, 2014
Doepfer announced an official Breakout Module for the A-127,
find out all about it at http://patchpierre.blogspot.nl/2014/03/doepfer-127-bom-filter-breakout-module.html

Modifications I : A-156 Quantizer Follow

A-156 with modification

Yesterday i picked up the spare parts that i ordered from Doepfer; a few switches, 3.5 mm sockets, LEDs and blindplates of different types and sizes. Now that i have them i couldn't wait to start with my first project.

One of my personal little annoyances that i have with the A-100 system are the tiny internal jumpers inside of some modules. Behind these jumpers are sometimes great functions that make these modules a lot more flexible.

Where i can, i will try to replace the internal jumpers with switches on the front on more modules, but i started with the A-156 Dual Quantizer Module.

A-156 after removing all the knobs
and frontplate

This module has two separate Quantizers, one that only uses a semitone-scale and Quantizer 2 that has much more options like minor/major/chord/quint/6th and 7th scales. There is a way to let Quantizer 1 follow Quantizer number 2 by replacing an internal jumper, but why there? It is probably a cost-saving thing from Doepfer's side but there is enough room on the frontplate of the module to place a switch with the same function. You can find a neat step-by-step guide with pictures on how to do this HERE , but it is quite easy.

Wiring the new switch

After removing the frontplate and drilling a hole for the new switch ( there is enough room above or under the printed 'Options Quantizer 2' text ) i could fit a new Doepfer 1-0-1 (on-off-on) switch in the hole and mount it back together again.

A-156 detail close-up

The wiring was quite simple, so even with my mediocre soldering-skills this was a piece of cake for me. The result is a simple and invisible modification that works perfect. Switch down couples the 2 quantizers, switch up puts quantizer 1 in it's original mode.

Okay... a similar result can be obtained with the use of an extra multiplier, but i found this one more adventurous... and rackspace-saving.

Now its time to experiment with the new options that i have. I can think of some nice patches already, but there are also some good suggestions for the use of this module and this modification at Synovatron's blog.