These are the build notes for the nonlinearcircuits Chopper / Bi-directional module. So what is it? It's a eurorack format voltage controllable electronic switching module.
The bottom section is similar to your old fashioned gate controlled bi-directional router. Functionally, it behaves very much like the Serge triple bi-directional router, though the circuit is very different. The top
section is based on a 70's delta modulator, (at least in concept). Delta modulation (DM or Δ-modulation) is an technique of analog-to-digital and digital-to-analog signal conversion. It's used for information transmission where quality is not of primary importance.
The
signals being switched are also sent through a comparator & they control the switching. Plus
you can add CV to all of this. Cool !
Cobramatic (Paul) & I are preparing for a gig probably next month in Sydney (The Carriageworks).
This patch is part of the installation.
We are undecided as to the final formal. It may comprise Eurorack & Kilpatrick modulars.
But we will definitely be bringing Buchla.
This patch is focused to provide drum/percussion sounds. It will possibly evolve into something else by the time we get to performing but for now, this is what it sounds like.
These are my build notes for the Steiner MicroCon (Eurorack format).
The original Microcon was a full voice module.
It's very rare & was first produced between 1977 & 79 as a complete synthesizer in a single module with its own power supply less keyboard. It has its own LFO, Filter, EG & VCO.
The original module measured 4 x 6 inches.
I purchased this modern eurorack kit from SynthCube.
The circuit/PCB was recast by David Ingebretsen in 2012, with permission from Nyle Steiner.
The euro format panel is designed by Clarke Robinson and produced by synthCube.
It might me fun to install the PCB in a box of the same dimensions as a homage to the original
module, though for the moment, I'll keep this in Eurorack format.
Install the resistors first.
There are 10 Diodes - Switching vR/100V Io/150mA (standard 1N4148)
And two 1n4001 Rectifiers (Vr/50V Io/1A T/R)
Headers & caps next.
The two trimmers and that tempco .... needs to be in contact with the IC.(SSM2210).
It's a dual matched transistor.
The Microcon uses two vactrols : VTL5C3/2. These are the same type used in my Buchla.
The original BOM uses a 74c14n Inverter - It's a Schmitt trigger.
This part is obsolete and has been replaced with a CD40106.
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For more Euro DIY builds click here: http://djjondent.blogspot.com.au/2017/12/diy-index.html
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This is a bit of an experiment running some EMS VCS3 video through a LZX video synthesizer.
The video synth is a whole new world.
Lots of scope for art & experimentation. I just love it.
My synth case so far.
I'm experimenting with lots of modules. As you can see there are some standard Eurorack
modules in this mix that work quite well with the LZX & Brown Shoes Only video modules.
The LZX visual cortex is very useful. It's becoming the heart of the system.
Even if you're not into nightclubbing it's a must see when in Cuba.
Housed in a natural cave Disco Ayala is lot's of fun.
At 1am every night there are live shows -- firewalkers & acrobats. This guy's got very tough teeth.
Cave nightclubs would never be allowed in Australia so lap up the atmosphere while you can.
Th Nonlinearcircuits DP Filter is a really interesting beast.
It takes ideas from the TB303 & Moog ladder and combines this with the EMS Diode ladder.
(The TB303 is a four stage diode ladder filter achieved
with transistors where the collectors are connected to base. The Moog is a straight transistor ladder filter).
This DP circuit replaces the diodes and transistors of these 3 ladder filters with opto-isolators
Opto-isolators (also called optical couplers or optocouplers) are basically a LED & a photo transistor in a light tight package. They use light to transfer electrical signals between circuits to keep them electrically isolated from each other. In this module the TLP521-2 is used.
This module is probably not the easiest one to start with if you are a beginner.
There are lots of surface mounted components, though on the bright side there is only one SMD IC.
(a 074).
I like to get the ICs out of the way so I'll solder the 074 first then the rest of the caps & resistors
The back side of the PCB also has SMDs. It's not the cleanest of SMD soldering efforts but should still work. Fingers crossed.
There are two SMD pads marked "c" on the rear side of the PCB....They are for 100k resistors.
Also, I'm using 0805 sized SMD components (its what I had in my store). The pads on this PCB are sized
1206. If you are using smaller ones like me, be careful when soldering the capacitors - let them cool down before soldering the other pad.
There are 2 versions of this filter - the standard using 100nF for C2,C3,C4 & C5 vs the TB-303
acid version which uses a 33nF on C2,C3,C4 & a 18nF on C5.
I'm building the standard version today.... all 100nF.(104).
The trannies next. Six BC547, and two BC557s.
I didn't bother to match these.
The 2 caps marked C22 & C23 near the power connection are 10uF electros.
...
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