Showing posts with label Modding. Show all posts
Showing posts with label Modding. Show all posts

Monday, January 22, 2018

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

Sunday, April 06, 2014

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

Thursday, March 07, 2013

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

Wednesday, November 28, 2012

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.

Monday, November 26, 2012

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.

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, October 27, 2011

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!

Friday, August 19, 2011

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!

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

Friday, January 28, 2011

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.

Thursday, January 20, 2011

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.

Tuesday, December 21, 2010

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

Monday, December 20, 2010

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

Sunday, December 19, 2010

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.

Friday, December 17, 2010

SiteTip II : Doepfer A-100 series modifications by Nick Keller.

Another nice site i stumbled upon in the last weeks in my search of Doepfer DIY info is the Doepfer A-100 series modifications site by Nick Keller at http://www.analoguehaven.com/usercomm/diy/

This site offers some great (and easy-looking) Doepfer-modifications, complete with step by step explanations and pictures. Most of the modifications are simple but very usefull and consist of adding more switches, inputs and outputs to the frontpanel. Very interesting stuff... I'm looking forward to try some of the examples and hope that the parts i ordered from Doepfer will arrive soon, so i can start experimenting on my first Doepfer-projects.

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

Monday, November 22, 2010

SiteTip I : Tone's Analog Synthesizer Projects and Products

I stumbled upon this interesting site last week; Tone's Analog Synthesizer Projects and Products. You can find it at http://synovatron.blogspot.com/
The overall site looks like a good start for everyone who is busy with, or starting on eurorack synthesizer DIY-ing and is operated by Tony Steventon, a UK electronics design engineer with a long interest in synths.
"Like most ideas it came out of trying to solve problems..." he wrote to me "... I could not fit either the jack sockets or bracketed pots on to standard 0.1" perfboard and came up with this idea over a year ago".

He continues "...several people have expressed an interest in learning how to take an idea through to a design and onto a prototyped module which I am quite tempted to do as a future 'learning' page on my blog..." "...I am working on my CV Tools module at the moment, which I have prototyped using my kits, but when that is ready for manufacture I am happy to consider some more ideas, I already have four promising ideas which may get developed either on my own or in collaboration with the idea originators."

Along with selling different DIY sets and prototyping kits, you can also order additional components for reasonable prices here. Listed are various Control pots (50k linear supplied as standard but 10k linear, 100k linear, 1M logarithmic or a mixture are available upon request), Pot mounting brackets, Decoupling capacitors, 16-pin headers, 3.5mm jack sockets, Red/green 3mm 2mA LEDs, TL084 quad op-amps (DIL), 14-pin IC sockets, 16mm soft-touch knobs (red, grey, orange, green, white, blue, yellow pointers), 10uF 16V electrolytic capacitors, 100nF ceramic capacitors, Headers - single, double, straight, right-angle, DPDT toggle switches to fit DIY2,  ...and more on request.

The site has an interesting (and growing) support page with all the datasheets and other practical tips on synovatron products. More info and discussion is possible at his dedicated Forum.


For sales, support and combined shipping enquiries you can contact synovatron@btinternet.com
CAUTION: These kits are intended only for experienced experimenters and constructors to prototype their designs. It is possible for you to destroy components or damage your synth if you are not careful. It is recommended that you use a separate regulated ±12V power supply for experimentation.

Wednesday, November 10, 2010

Happy Knobbing III - New Joystick-Lever

The latest minor modification to my A-100 system  is the replacement of the A-174 Module's joystick.

I finally changed my black plastic lever with a newer aluminium one that i ordered at Doepfer last week.

Modules before 2007 had the black plastic lever as standard, all modules delivered after 2007 already have this aluminium lever.

It's just a small optical change, nothing more. The new lever is a bit shorter, but does have a nice/better grip though. And that for only 10 Euro's...

<  Old vs. new lever

Friday, September 24, 2010

Ribbon Controller USB-connector Project Part 1

After a few weeks of randomly disturbed signals, the USB-connector of my A-198 Ribbon Controller finally broke a pin... or two.

It's not the first time this happened, last time was a little over 2 years ago.
It is just one of the very few weak spots of the whole A-100 system, it might be cost-related, but i'm not sure about that.

Back then, Doepfer was so kind to send me a USB connector for free, and i know that if i'd mail them i can get one again, but i'm not sure this solution will work very long, as i use this Controller a lot lately.
The weight of the USB-connector (and cable) is just too big, and the way i hold it (guitar-style) is probably not the best way to hold it (?)





My plan is to by-pass the USB-connector by wiring the cable in another way. I'm still not sure how exactly, but i'll see. And you will.

Thursday, September 23, 2010

Happy Modding II - Joystick Spring Removal

The A-174 Joystick Controller outputs 2 control voltages, generated by a spring-loaded X/Y cross potentiometer.
Two springs inside the module take care that the controlling lever returns to it's centre position if untouched.

One very easy modification is the removal of a spring from this module


The process of removing is quite simple, and is described clearly on the Doepfer DIY page / section 4.2.10.

I decided to remove one spring only, the horizontal one. ( X-axis )
This way the Controller stays fixed, even if i let go of the lever, and doesn't automaticly go back to the middle.

If you do this to the Y-axis ( vertical ) of the module, the lever would fall down to it's lowest position due to gravity, which also can be handy in some situations, but not mine at the moment.

This small modification adds just that tiny bit more flexibility to my setup.

Note: Pay attention that warranty is lost if the joystick is modified !

Saturday, April 10, 2010

Happy Knobbing II - Colored Switches

I finally found what i was looking for for a long time.

A year ago ( or so ) i saw an A-100 system with colored switches on it.
For a long time i have been looking for them too, and now finally i found them and ordered them. ( pretty easy after all, via Conrad )

They are just small plastic mini-sleeves, and they fit perfect on the A-100's switches.
They also provide a little bit more grip and make the switches easier to handle.
I ordered them in all the four available colors ( green, black, yellow and red ), so i can sort of 'color-code' the system as much as possible. Not sound-improving, but just nice eye-candy... again.