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

Glow In The Dark Patch Cables

A nice way to pimp your eurorack;
Glow-in-the-dark patch cables by Expert Sleepers, the people who brought you Silent Way and more...

Video: Glow-in-the-dark patch cables

Available in 300mm, 500mm and 800mm lengths.
Order at http://expert-sleepers.co.uk/accessories.html

via @expertsleepers

Bus Board Connections

I wrote about the busboard access that several A-100 modules have earlier in this blog.
All modules that can read and/or write to the A-100's internal busboard are mentioned in THIS post.

I did forget to mention a few things in my earlier post, and thanks to the Yahoo Doepfer Usergroup i stumbled upon the A-100BC (CV/Gate bus connection cable) that can be used if the CV and/or gate signals of two bus boards have to be connected internally.

For this the CV or gate corresponding connection jumper in the middle of the bus board is removed and replaced by the connector of the (20 cm. long) A-100BC cable. 

It is possible to connect the CV and gate lines of two bus boards independently (i.e. only CV or only gate or both). 

The cable is made of two wires with suitable connectors on each side. 

Usually one wire is used for CV, the other for gate, but the wires can be ripped up and used separately. 

Dieter himself did a great post in the Doepfer Usergroup that nicely explained how the internal busboard connections work:

" The main function of the bus is the power supply of the A-100 modules (-12V, GND, +12V and additional +5V for a few modules) - In addition a CV and Gate line are available
- Some modules can pick-up the CV signal (e.g. A-110, A-111-1, A-111-5, A-143-4) from the bus depending on the jumper setting on the module (full list HERE /PP)
- Some modules can pick-up the gate CV signal (e.g. A-140) from the bus depending on the jumper setting on the module (full list HERE /PP), but most of the A-100 modules have no access to the CV or Gate signal of the bus

- Other modules may work as transmitter for the CV signal to the bus (e.g. A-190-x, A-185-x) depending on the jumper setting on the module (full list HERE /PP)

- Other modules may work as transmitter for the gate signal to the bus (e.g. A-190-x, A-185-1, A-164-1) depending on the jumper setting on the module (full list HERE /PP)

A-100 BC cable

- Pay attention that only ONE transmitter for CV and ONE transmitter for gate are allowed (otherwise modules may be damaged)

- Using the internal CV and Gate lines of the bus is optional (one may also patch the required connections via the sockets at the front panels), but using the internal CV and Gate lines may simplify the patching at the front panels (e.g. if several VCOs have to be controlled by the same CV, in this case the A-185-2 is recommended as CV transmitter to the bus, the A-185-2 allows also common octave switching and common frequency modulation of all VCOs as well as CV summing, e.g. from a sequencer and CV keyboard or Midi-to-CV interface)

- Both the CV and the Gate line can be interrupted in the middle of the bus board to establish two different CV/Gate areas.
For this the corresponding jumper in the middle of the bus board has to be removed.

- A special CV/Gate bus connection cable A-100BC is available.
This cable can be used to connect the CV and/or Gate lines of two different bus boards.
To connect the two boards the same pin headers of the two bus boards may be used that also interrupt the CV and/or Gate lines, but it is also possible to connect the corresponding pins (Gate and/or CV) of other unused bus connectors (i.e. one of the 14 16 pin connectors) "

Source: Yahoo Doepfer A-100 Usergroup

CV / Gate Cable Length

A few times I've been asked about how patch-cable lengths ( of CV and/or Gate signals ) can affect signal strength.
I found a few interesting posts in the Yahoo Doepfer Usergroup that might make things a bit clear to you.

First of all;
Gate cables even longer than 10 meters usually are no problem.
Although a gate signal might get slightly weaker when you use extremely long cables, the (simple) gate signal will often stay strong enough to trigger your modules.
CV-Cables of this length may have a slight loss depending on the electrical characteristics of the input and the output.
There are ways to measure it,  but it is very difficult to judge whether a not completely clean octave tracking is caused by long cables.
Real loss of signal quality starts with asymmetric audio cables at such a length, and you have always to keep in mind that electromagnetic and electrostatic influences (hum and sizzle) can affect longer cables more than shorter cables.

" From a theoretical point of view (for anyone interested) the key things are output and input impedance, cable capacitance and resistance.
If you take a relatively standard low-cost coax cable of say 380pF/m and 128 Ohms/km this will not cause any noticeable loss in audio top-end from a 1k Ohm output impedance until you exceed 20m or so but you are more likely to get increased noise and interference.

From a CV point of view the cable resistance is a more important parameter (if your CV is controlling VCOs that is) but even 20m is only 2.6 Ohms so this can be ignored compared to the high input impedance of most VCO CV inputs; again long lengths are more prone to pickup so 50Hz mains can modulate the CV.
( you may also experience hum loops by just connecting gear together that is powered from different power outlets across the room ). " *

( * thanks to Tony Steventon from Synovatron for the 2nd half of this post )

A Question of Cables

Doepfer sells  patch-cables for the A-100 system (3.5 mm plug mono jack) in many different colors and sizes.
The latest addition to the Doepfer assortiment are the orange 50 centimeter patchcables with angled plug on one side. 

The prices are fairly acceptable, and the more you buy ( at once ) the cheaper they get each...
Sizes vary from 15 (yellow), 30 (black) , 50 (grey), 80 (red) , 120 (blue) to 200 (green) centimetres, but i wish they also had other lengths. (...and colors)

Let me know in the comments if you know a place where they sell patch-cables in other colors or lenghts, it will be appreciated.
Purple ones would be nice... but not too long... ;-)