Ljunggren Audio

Roll Your Own

Eurorack DIY

Sequencing

 
 

VC Sequencer

 

Download assembly manual for v1.5 here. (3.5MB)

Download assembly manual for v1.3 here. (2.7MB)

 

Compact 8-step sequential voltage source in 10hp with classic forward/backward operation using a clock, and any kind of pattern you like using control voltage levels scaled to each step of the sequencer, allowing the waveform you feed it with to determine the running pattern.

 

Examples of this would be a ramp to make it go forward, saw to go backward, triangle for pendulum, S&H'd noise for random etc. You could also use another sequencer's pattern to control the pattern of the VC Sequencer, the possibilities for exploration are many.

 

All low latency CMOS and Opamp circuitry. No software or micro processors.

 

It can keep sync above audio rates. Overall latency on version 1.3 is ca 5us (0.005ms) until the step changes + up to ca 10us (0.01ms) to change the volt (bigger change = longer time).

 

In version 1.3 the CV mode got an improvement allowing it to reach thru the whole audio range. Effectively extending the VC Sequencers funtionality into also being a 3 bit hands on waveshaper.

 

In FWD/REV mode the CV/Clock input use a schmitt trigger that turns from low to high at ca 2.5V and from high to low at ca 2.3V (a window of 0.2V or 200mV), the same window applies to the Reset input.

 

In CV mode the CV/Clock input use a set of 7 schmitt triggers with a window of ca 10-15 mV (0.01-0.015V). The first step don't need it's own schmitt trigger. Each step is separated by ca 0.625V.

 

Expanders will offer chaining of 2 VC Sequencers for 16 step operation and unlimited extra parallel channels of CV or gate/trig, for example our first expander that have individual gate or trig outs for each step in 4hp. The 16 step expander will add an extra latency and lower the maximum clock frequency in 16-step mode.

 

The VC Sequencer Kit contains 3 PCBs to be populated with components. It might not be suitable for one of your very first builds as it is a little larger build and there are connections between PCB's.

 

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

 

Grayscale panels as long as stock lasts: @Grayscale @synthCube

 

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

SEK 1771 for an assembled VC Sequencer

SEK 940 for the DIY kit

SEK 300 for PCB only*

SEK 107 for panel only*

 

Download assembly manual for version 1.5 here. (3.5MB)

Download BOM for version 1.5 here.

Download schematics for version 1.5 here.

 

Previous versions:

Download assembly manual for version 1.2 here. (3.6MB)

Download assembly manual for version 1.3 here. (2.7MB)

Download schematics for version 1.2 here: PCB1 PCB2 PCB3

Download schematics for version 1.3 here: PCB1 PCB2 PCB3

Both version 1.2 and 1.3 share the same PCB1.

 

 

Basic specifications

Width: 10hp

Depth with power cable attached: Less than 45 mm.

Power version 1.2: +28 mA / -11 mA

Power version 1.3: +22 mA / -11 mA

Power version 1.5: +22 mA / -11 mA

 

 

 

 

 

Trig Xpander (for VC Sequencer)

 

Download assembly manual for version 1.2 here. (1.4MB)

 

This will give your VC Sequencer 8 individual outputs for each step outputting either a trigger or a gate, selectable with a jumper on the pcb, and a 9th output that gives you a trigger for each step progression.

 

Also on board is a trimmer for setting the trigger length to your liking (ca 1-20 ms). Usually you wan't to set this as low as possible to reach higher rates. Different trig lengths can give a different sound from pinging filters or striking lowpassgates. Some vintage gear also require longer trigs. The gates are high for the full duration of each step.

 

The outputs are diode isolated, this allows for passive mixing of the outputs using a passive multiple/stackcable/IV cable, or a switched multiple/OR combiner such as the Doepfer A-182 or Low-Gain Short Bus.

 

The kit comes supplied with two PCBs (one with a v-cut that you break into two), front panel (PCB material), component kit, power and expansion cables and mounting screws. Solder and tools are not supplied.

 

Grayscale panel preorder open: @Grayscale

 

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

SEK 769 for an assembled Trig Xpander

SEK 527 for the DIY kit

SEK 152 for PCB only*

SEK 92 for panel only*

 

Download assembly manual for version 1.1 here. (1.2MB)

Download schematics for version 1.1 here.

 

Download assembly manual for version 1.2 here. (1.4MB)

Download schematics for version 1.2 here.

 

Basic specifications

Width: 4hp

Depth: 45 mm

Power: +12 mA / -0 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.

Penta

 

Download assembly manual here. (2.1MB)

 

The RYO Penta is a compact 4hp 5 step sequencer for eurorack that's easy to build and low cost, without compromising on our usual quality standards such as buffered output, schmitt triggers on inputs and reverse polarity protection.

 

It is great for simpler sequencer tasks such as basslines and arpeggios, transposing sequences, filter cutoff or anything where a repeating stepped modulation is wanted for adding movement to the sounds you're making.

 

Sending a clock to the CLK input will progress the sequence, the Penta has 5 minishaft potentiometers for adjusting each of the 5 steps voltages, ranging from 0 to +5V. A pattern length switch is available for selecting 3, 4 or 5 steps pattern length, this can of course also be set by using an external gate or trig into the RST (Reset) input.

 

We've also added a bonus for the more seasoned builders in the form of +5V GATE output solder pads for each of the sequencers 5 steps, as well as an input pad for HOLD which will lock the sequence to the active step as long as a gate is present. Info on how to perform a homebrew expansion can be found on the last page in the assembly manual.

 

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

SEK 800 assembled Penta

SEK 540 for the DIY kit

SEK 152 for PCB only*

SEK 92 for panel only*

 

Download assembly manual here. (2.1MB)

Download schematics here.

Modifications to Penta can be found here.

 

Basic specifications

Width: 4hp

Depth with power cable attached: 39 mm.

Power: +6 mA / -1 mA