Quick Tip: Velcro Cablebinders

Velcro cable-binders in different
sizes

Okay... I'm re-organizing the studio (again) and came to the conclusion that it was a good idea of me to use Velcro cable-binders to keep my audio- and MIDI-cables together, the last time that i put up my current setup.

It was a piece of cake removing the old ones, and it works better than the plastic cable-ties (tie-wraps) that I used before that.

Velcro cable-binders can be found in a lot of different colors and sizes at your local hardware-store or cable-supplier.
You can even think about color-coding your cables this way and use different colors for audio / MIDI etc...

Some (audio-)cable-manufacturers even package their cables with Velcro cable-binders nowadays, and often they are long enough to cut into a few smaller ones...

More Quick Tips at http://patchpierre.blogspot.nl/search/label/Quick%20Tip

Quick Tip: Differences in Eurorack Modules

When you have multiple modules of the same brand and type , you might sometimes experience small differences between those Eurorack modules.
Sometimes oscillators are tuned differently and you can't get them to match.
One may sound lower than the other with each's controls identical, yet they sound different..

This is often not something to worry about.

Four A-110 VCOs that look the same,
all sounding (slightly) different.

Although most modules are thoroughly tested, some batches may indeed sound a little different due to (internal) trim-pot settings, differences due to tolerances of the electronic parts, etc...

If you want to compare your modules, it is always smart to check the production date/ batch number on the test label and/or on the PCB (version nr) first.
Usually this can be found at the inner side of the front panel.

If the numbers match, and one of your modules does sound different than the other one, you might check out the trimming pots on the backside of the module on the PCB.
In most cases this can be easily fixed with a small screwdriver once you located the right potentiometer (often printed on the PCB or can be found in a manual).

Sometimes it just has to do with other components.
During the production-years of a module the values of all kinds of parts of your module may have been changed a bit (for example R77, R86, R88).
These differences can sometimes be audible, sometimes only to the trained ear...

Especially the specifications of a main circuit like the 74HC4046 (Used in the Phase Locked Loop - A-196 PLL module) may differ for different manufacturers (even different batches from the same manufacturer) of this circuit.
Because the PLL module is not a precision module like a VCO there are no trimming potentiometers available to balance such tolerances.
You'll just have to live with that...

Sources: Doepfer website and Doepfer A-100 Yahoo Usergoup

Quick Tip XIII : Improvised Multiples

The bigger your Eurorack gets, the more often you need longer cables.
In case you don't have enough long cables, i would advice you to put an A-180(-2) Multiples module somewhere in the middle of your system so you can extend your cable-reach from there.

A-164-1 as
improvised
Multiple

If you don't have enough multiple modules, you can also look if you have other options.

A-165 Trigger
Modifier Inputs

You should know that some Doepfer modules have multiple in- or outputs that are interconnected in a way that they can act as multiples as well...

You can recognize these in/outputs by the connected line between the mini-jacks.
The A-175 Voltage Inverter  and A-165 Trigger Modifier  are nice examples,  both have two separate channels, so also two multiples.
The A-164-1 Manual Gate module can even be used as 3 separate multiples.
The 2 outputs on the A-119 External Input module are connected together too, as well as the audio inputs on the A-126 Voltage Controlled Frequency Shifter.

A few more Doepfer modules also have this option, let me know in the comments if you find other modules that have this possibility.

This 'trick' works for CV signals and for audio but I should mention that if you use these modules as an improvised Multiple, most of the times you cannot use the module's original functions at the same time.

Quick Tip XII : A-149-1/2 Connection

Since i recently own an A-149-1/2 Quantized/Stored Random Voltages combination i thought it would be a good idea to spend a few blogposts on it.
Sadly something in my mixing-desk popped yesterday, so i can't make any demo's of it right now (or even listen to loud music...) I hope fixing it will not take too long... or cost too much :-(

This first post is very basic, but i have seen the question on how to connect these two modules pop up on forums several times.
This can also be found in the A-149-2 Manual (PDF), but i guess this post (and picture) will provide all the info you need.

The A-149-2 must be placed directly next to the A-149-1 module (I prefer it on the right side as it seems more logic to me)

A-149 connection - A-149-2 on top, A-149-1 below that
The inter-connecting ribbon is the right one,
the ones on the left should be connected to the busboard

The special connecting ribbon cable is equipped with 10 pin female connectors on both ends.
Join the two modules with the supplied 10-way ribbon cable.
Make sure that the ribbon cable is not twisted, and that the colour-coded section is oriented the same on both modules.

One of the female connectors is already connected in the factory to the pin header labelled "JP2 TO A-149-1 EXPANSION CONNECTOR" on the A-149-2 pc board.
The second female connector of this cable is used to establish the connection between A-149-2 and A-149-1.
This female connector is put on the pin header labelled "JP5 EXPANSION" on the main board of the module A-149-1.
For both modules the cable has to be the same polarity (i.e. red wire to bottom for both modules).

Pay attention not to damage any of the parts on the boards.

Quick Tip XI : Eurorack Screws

Okay, this seems like pretty basic Eurorack knowledge, but every now and then I see this question popping up on several forums and sites.

The standard Doepfer eurorack screws - M3x6

It seems a lot of people run out of Eurorack mounting screws very often.
A lot of them don't seem to know what types are used and/or where to get them.

In Doepfer Euroracks standardized lens head screw DIN7985 M3x6 are used.
DIN is the German edition of ISO standards and
the ISO metric screw threads are the world-wide most commonly used type of general-purpose screw thread.

The 3 stands for the diameter of the wire, and 6 stands for the length of the screw... both in millimeters (mm).
For the Doepfer racks, don't use longer screws...

I got mine from a local hardware-store (GAMMA), and i guess you will be able to find some near you...
Of course there are many other types of mounting screws available that fit... in different shapes and colours, so the choice is yours.
Just Google "M3x6" and you will find plenty of options.

A tip from Oliver Chesler from wiretotheear.com in the comments is that you can also use 3mm Nylon Plastic Washers between your screws and the modules.

If you want to resell your modules scratch-less this might be a good idea.

Quick Tip X : The Warm Up

Good performances need a good preparation and a warm-up.
That does not only count for sports-prestations, but also for your (eurorack modular) analog synthesizer.

2 Doepfer VCOs that could use a good warm up

If you are looking for getting the best out of your Doepfer A-100, understand that you need to give your system at least 20 to 30 minutes to warm up.
If you don't give it that amount of time, the tuning can/will probably be (slightly) off.

To be clear, it's not a question of the "A-100" warming up, but of the modules installed.
In some cases, the warm-up period of a module is mentioned in the manual or on the web-page of the module in question.

Especially VCOs like A-110, A-111-1, A-111-5, A-143-4 need a warming-up to become stable and reliable.
If no warm-up period is mentioned the VCO is stable very soon (like the CEM3340-based A-111-1).

The PSU type (Doepfer power supply I or II) has no influence.

Quick Tip IX : Record Everything

Video's like these (by marihutten on a pretty big A-100 system) remind me to always record everything you can, on video or at least in audio.
If you only knew how often i regretted not recording that last jam, demo or interlude, it often turns out you miss the best things...
Or is that just my bad luck?
Other benefit is the ability to review your recording later, by yourself or by others... you might be surprised by the reactions from different listeners...
Or how about using snippets of your recordings in later projects?
Possibilities are endless, your limit is your imagination...

Video: Clock Divider and FM on Doepfer (11:23)
http://www.youtube.com/watch?v=pe51is2ltu8


" My first try with the clock divider on the Doepfer. Too bad I forgot filming the third patch I that I created during that session that was an ADSR that went through an Audio Divider that went through the clock that later went through a morph filter. Sounded sick.
This one sounds kinda boring but I was trying something simple with 3 VCOs of triangle waves to see if I got the gist of the clock divider."

Uploaded by marihutten on 2/2/2012

Quick Tip VIII : Mounting the A-174-2 Wheels Module

Please be aware of this when you want to install an A-174-2 Wheels Module in your A-100 rack;

A-174-2 Wheels Module, note the pot on the left

As the potentiometer of the left wheel projects about 10 milimeters beside the rim of the front panel, a 2 or 4 HP blind panel has to be mounted left from the module. "

A-174-2 Sideview

Unless the module left to the A-174-2 has sufficient space in this area of course.Like an A-174-1 Joystick Controlled CV, for example.

None of the A-100 modules that are 4 HP wide fit there...

Quick Tip VII : Battery Check

In the A-112 VC Sampler /Wavetable Oscillator and some other devices rechargeable batteries (accumulators) are used for memory backup of preset data.
These electronic parts have a limited lifespan and have to be inspected at least every two years.

A-112 VC Sampler /Wavetable
Oscillator battery

Before the inspection the device has to be disconnected from mains voltage !
If the battery has a leak or if the measured voltage of the battery differs more than 10% from the target voltage the battery has to be replaced.
The target voltage (2.4V or 3.6V) and is printed on the battery.
The replacement should be carried out by qualified personnel only. 
The old battery has to be removed (desoldered) and the new one put in (soldered).
If you are able to carry out the replacement yourself you can purchase the rechargeable battery as a spare part from a supplier in your country. Any other rechargeable battery with the same voltage (e.g. 3.6V) can be used provided that it fits mechanically.

It is not allowed to put the old battery in the normal garbage. Please forward the old battery for recycling to a suitable receiving office.

The following Doepfer devices are (or have been) equipped with a rechargeable battery 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.
Available e.g. from GP (3GP-60) or Varta (3/V80H), in Germany e.g. from www.reichelt.de (order no. 3GP-60), in USA from www.mouser.com (order no. Varta 3/V80H / 672-55608303059)

More info HERE

Quick Tip VI : Theremin Antenna

By accident i learned that the same kind of thing that i advised for the A-198 Ribbon Controller (to remove the USB-cable from the controller after use, read the post HERE ) counts for the A-178 Theremin Controller's antennas as well...

If you, like i, have your A-100 system placed upright , the weight of the antennas is just a little bit too much for the mini jack connector.
The permanent sideways pressure, caused by the weight of the antenna can cause loose contacts of the connector. If you have your module installed on a flat (tabletop-like) surface the plugged-in antenna cause less sideways pressure and you'll probably be safe.

Although Doepfer uses a new type of jack sockets since 2003 with stronger springs and so-called "curly rear contacts",  loose contacts can hardly be prevented.
But don't worry, if this problem occurs it is not a huge problem because most of the times you can fix them yourself by following the instructions that you can find HERE.

In my humble opinion it is just better to unplug your antenna from your A-178 module when you are not using the Theremin functions.
Better be safe than sorry...

Quick Tip V : Solving Jack Socket Contact Problems

Some ( minor ) contact-problems have been reported with the older mini-jack sockets ( S6PC, manufacturer: Cliff / England ) that were used by a variety of manufacturers of electronic equipment.

Unfortunately Doeper also used these sockets in their earlier modules, so these problems can happen with your module too, if yours was made before the end of 2002. 

The 3.5 mm miniature jack sockets used in the A-100 system before about 2002 have been very sensitive to the diameter and shape of the jack plugs of the cables used to interconnect the modules.
If you have contact problems with older modules Doepfer advices the following procedure:

• Disconnect the A-100 system from mains due to safety reasons
• Remove the module from the rack and disconnect the bus cable if necessary
• Insert the jack plug into the socket causing contact problems
• Press down the hollow of the "hot" contact very carefully using a slotted screwdriver (see picture at the right)

• This should lead to a good contact between jack plug and jack socket
• If the result is not good enough repeat the procedure without inserted plug but pay attention that the upper contact spring does not slip below the lower one. Use the screwdriver very carefully !
• Connect the bus cable to the A-100 bus board (if removed)
• Assemble the module into the A-100 frame
• Connect the A-100 system to mains and turn the system on
• Now the contact problem should no longer occur
  
P.S. Since 2003 a new type of jack sockets with stronger springs and so-called "curly rear contacts" is used in the A-100.

Source: Doepfer FAQ

Update February 17 - Nice follow-up at the Synovatron blog

Quick Tip IV : Ribbon Cable

A small personal advice for owners of an A-198 Ribbon Controller or R2M manual controller;

Please unplug the USB-cable when you are not using the instrument.
The weight of the cable has more then once broken the USB-connector on my Ribbon Controller.

Or try to keep the controller and cable on a flat surface...

...also see THIS post.

Quick Tip III : Vocoder testing

Ideal for ( Doepfer ) vocoder testing;


Try feeding an audio-book or a recording of your favorite radioshow through your system while tweaking your vocoder settings.

Speech-only programmes are perfect for this purpose.

Short demo:
  In the Morning Vocoder test by NetPierre
* original audioclip from: http://NoAgendaShow.com / http://NoAgendaShots.com

Quick Tip II - Frequency Displacement ( Picture )

"If, instead of patching the outputs from the analysis section to their  'proper' respective outputs in the synthesis section, you swap them about instead, interesting frequency displacements occur in the vocoder output"

* from the A-129/1/2 Modular Vocoder Manual

Quick Tip I - Cleaning the A-100 with a Brush

As most of us know, the Doepfer A-100 can be quite a dust-magnet, and with all the cables and knobs, it isn't the easiest instrument to clean.

A dry piece of cloth often gets stuck between the wires if you try, and cleaning between the knobs can be awkward at some times

What i prefer for a quick cleanup is a dry long-haired (painting)-brush.

It quickly removes all the dust from the surface of your modules without any problems.