Ljunggren Audio

Roll Your Own

Eurorack DIY

Switches

PATHS - A Cycling Sequential Switch

 

A 4:4 cycling sequential switch, featuring simultaneous forward/reverse stepping, hold, reset, and an additional voltage controlled mode based on the same design as our VC Sequencer. Also on board are push buttons for each function enabling you to play and perform the switching with a more human input.

 

This sequential switch will do all your standard 1>2, 1>3, 1>4 or the other way around with great real-time as well as external voltage controllability.

 

But its when you start playing around with multiple sources and destinations that things start getting fun and weird! You could for instance shuffle around four different trigger patterns to trigger four different percussive generators for interesting variations, or why not 4 oscillators shuffling between 4 different destinations, panned and processed in various ways?

 

Whatever your sequential switch application might be, we're confident the Paths is up to the task!

 

Just like the VC Sequencer it is clockable by very high clock rates (100 kHz tested) and CVable with full audio range. All for your experimental waveshaping duties.

 

Clock Mode

When clocking with FWD clock input or button the sequence will advance one step forward. When clocking with REV clock input or button the sequence will advance one step in reverse.

 

If a clock comes in exactly at the same time on both inputs the forward will have priority over the reverse.

 

CV Mode

In CV mode there is two CV inputs. The one that shares the reverse clock input is full wave rectified and the one that shares the forward clock input is half wave rectified. It uses an active rectifier without voltage drop or a dead zone around 0V.

 

The half wave rectified (FWD) with one bump on the rectifier symbol, will clip any signal below 0V and above 5V. The difference to the full wave rectified input (REV) with two bumps on the rectifier symbol, is that it will turn any negative volt into positive as well. So -1V is the same as +1V and -5V is the same as +5V etc.

 

The CV inputs are mixed together so they can be used at the same time.

 

The steps toggle switch and the red buttons are inactive in CV mode.

To limit the number of steps in CV mode you can use an attenuator to attenuate the CV down to only reach 2 or 3 steps.

 

Four separate switches

It's essentially four separate switches that is commonly controlled and shares ins and outs.

When I/O1 is connected to O/I1, I/O2 is connected to O/I2 and so on.

When I/O1 is connected to O/I2, I/O2 is connected to O/I3 and so on, and I/O4 is connected to O/I1.

When I/O1 is connected to O/I3, I/O2 is connected to O/I4 and I/O3 is connected to O/I1 and so on.

All the routings can be seen in the picture linked here, each module represent one of the four steps as the LEDs next to the jacks indicate.

 

2/4/3 Steps and reverse direction.

The toggle switch that controls number of steps works a little pequliar due to the CMOS CD4516 counter IC. Reset always takes it back to step 1/first LED lit. We could then choose to always let it reset on step 3 and 4 respectively for 2 and 3 steps.

 

But when run in reverse it would mean that with the toggle switch on 2 steps it would go 2 steps before it hits step 3 and resets. All good so far but when 3 steps were selected it would just stay on step 1 when clocked in reverse as step 4 would be next and that would reset it. So we choose to let it reset on step 2 when you run it in reverse so it goes 1 -> 4 -> 3 -> 1.

 

This opens up the possibility to clock forward and reverse with different triggers or button presses and therefore make it go in controlled irregular patterns. 1 -> FWD -> 2 -> FWD -> 3 -> REV -> 1 -> REV -> 4 -> REV -> 3-> FWD -> 1 as an example. Add a little random trigs or button presses and it will be less controlled.

 

Two parallel 1:2 switches

You could also patch it like two commonly controlled parallel 1:2 switches if you only run it in one direction. Easiest is forward direction: I/O1 : O/I1 & O/I2 respectively I/O3 : O/I3 & O/I4

 

 

Kits and price

Kits comes supplied with PCBs, front panel (PCB material), component kit, power cable and mounting screws. Solder and tools are not supplied.

 

Recommended Retail Price in SEK excl. VAT/sales tax.

SEK 1049 for the DIY kit

SEK 1914 for the assembled module

SEK 300 for the PCB only*

SEK 100 for the Panel only*

 

Download assembly instructions and BOM here (2.7MB).

Download schematics here.

 

Basic specifications

Width: 8 hp

Depth: 46 mm.

Power: +12V 30 mA / -12V 8 mA

 

 

 

* Regarding our PCB/panel only offerings, please note that these are mainly offered due to popular demand from the experienced DIY community. Hence we are counting on that you know what you are doing and how to source parts. If you feel the least bit uncertain, please consider going for the kit.