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

Quotes V : Alan Pearlman

"The electronic instrument's value is chiefly as a novelty. With greater attention on the part of the engineer to the needs of the musician, the day may not be too remote when the electronic instrument may take its place ... as a versatile, powerful, and expressive instrument."

Alan Pearlman wrote this in 1948... 21 years later he founded ARP Instruments Inc.

Most Wanted IV - A-157 8x16 Step Trigger Sequencer

At NAMM 2010 in Anaheim USA, Doepfer showed a very early prototype of the A-157 8 x 16 Step Trigger Sequencer. There's not much information available about this module, besides the info in the NAMM 2010 News PDF on the Doepfer site. Even Doepfer's own Future/New Modules section doesn't have any info on it.

What we do know ( about the prototype(s) ) is that it will be a 'simple' and affordable trigger sequencer (only 8x8 steps, no preset management).
The final module will be equipped with assigned LEDs (arranged in 8 rows with 16 steps each), 8 trigger outputs and clock/start/stop/reset inputs.
It generates 8 trigger signals that are set by the buttons. The LEDs are used to show the active steps and the external control signals clock, start/stop and reset are used to sync the unit to other A-100 modules (or via suitable interfaces to Midi/USB).

An additional preset management will be added to the final version of the module. At the time Doepfer was also thinking about a low cost version of this module with an 8x16 or 8x32 display (like the left unit in the picture) but with only one row of buttons that had to be assigned to one of the rows in question.
The expected date of delivery of summer 2010 was never made.

In fact i haven't found anything more on the web or in the forums about this module, what the reactions were, or a new expected release date.
They are probably still working hard on perfecting the module. The module shown at NAMM wasn't even finished but did give a nice insight on what they are working on.
I like the idea and layout of the front-panel, but personally i prefer my Clock and Reset inputs at the left side of a module, i guess they will at least change that in the final product.

I'd love to have one in a near future, programming rhythmical stuff will become much easier with a module like this, looking forward owning one, but i am afraid i have to wait a while...

Booktip VI - The Museum of Synthesizer Technology by Martin J. Newcomb

Okay... the cover-design of this book isn't outstanding, but the content is in fact very interesting.

This book, simply called The Museum of Synthesizer Technology, written by Martin J. Newcomb in July 1994 shows the huge collection of what used to be the Museum of Synthesizer Technology that was situated in a  part of Berkshire, UK.

The museum, opened by Bob Moog, only existed for a few years ( 1994 - 1997 ) and was at the time the largest collection of analogue synthesizers in the world.
The idea was nice; the aim was to preserve all these analog synthesizers for future generations, and today's generation would be helped by exhibiting them and by keeping the (service- and normal) manuals available for the public.

Basically the book ( A4-sized, 118 pages ) is an overview of the museum's collection, with a lot of large (color-) pictures and accompanied by well-written background-information on the different synth-companies and types.
...most of all i like it for it's pictures...

Not included with the book, but there was also an interesting video out about this museum with uncut demonstrations, that was published in 2006 by Analogue Heaven, called Analogue Heaven The Museum of Synthesizer Technology. It is a revised release of the original museum-video, but including some extras.
Find the 65 minute documentary HERE (in six parts)
or HERE (full version)

The book has no ISBN number.

Racks, Cases and Monsterbases

In the beginning it was easy; you only had a few choices:
You could either buy a 3-unit high rack (A-100G3), a 6-unit high rack (A-100G6) or the 6-unit high suitcase version (A-100P6) from Doepfer to mount and organize all your A-100 modules.
Nowadays you can choose from a huge variety of other housings from Doepfer, from 32HP width miniature-cases up to 168HP monster-cases.
You can even make your own cases/cabinets with the low-cost DIY-kits containing rails, a power supply and bus-boards.

The most economic versions nowadays are the low-cost plain wood cases (A-100LC6/LC9) ,which cost about 35% less than the metal and standard suitcase versions.
If that is not your thing you can always go for the monster-cases;
Twice the usable width of a 'normal' rack, but finished with a black or grey finish in a flightcase-look are available in many different shapes and sizes.
There's even a monster-base that fits under these cases, with 2 rows of 168HP width, one with horizontal alignment and a second with a 45 degrees inclined row.

- note from the Doepfer-site: " ...the 12U monster cases are a bit difficult to handle by one person only "

I recently ordered my 4th metal G6 case because i already owned three of them that are filled up to the max. I already have some loose modules lying around that i would love to have back in my system again.
Budget-wise i wanted to go for the LC9-version(s), but then i had to re-arrange the rest of my system too, to give it a same look. Too much work for now.

For my next expansion i am considering building myself a cabinet, using 5 or 6 A-100DIY1 kits . 

That is probably by far the most in-expensive way. If i sell my G6-cases second-hand, i will probably even have some money left to buy me an extra module or two. We'll see...

A-136 Distortion / Waveshaper

The A-136 Distortion/Waveshaper module is a nice distortion/wave-shaping module with external CV control possibilities. It can be used for audio-distortion, but also to modify control voltages ( create new control waveforms made from LFO, ADSR, or Random voltages ) with it.

The module divides the incoming signal into 3 different components; the positive, the negative and the original signal. The 5 knobs and the 2 CV inputs let you adjust the positive and negative amplification and the clipping levels.

With all the different different settings you can create complex wave-shapes and impressive sounds, but to be fair, i have heard better (extended?) distortions. This might perhaps be the reason why Doepfer advices you to use it in combination with filters... not sure though...

For mild and subtle distortions this module sounds alright, but the wilder, clipping distortions are a bit too extreme for me.
Personally i prefer the A-137 Wave Multiplier or the A-116 WP Waveform Processor controlled by random voltages, for the more interesting ( subtle and extremer ) wave-shaping.

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.