Ljunggren Audio
Products
Optodist
Download assembly manual here.
A compact, easy to use, easy to build and great sounding distortion module which will also work as a VCA if desired.
The Optodist is based on two Advanced Photonix (formerly known as Silonex) optocouplers that gives its characterful overdriven sound and plucky dynamic response to CV, it is equally at home adding a bit of extra crisp to highs and mids or warming up your lows as it is turning a resonant filter into a howling beast or your drums into crushing carnage. The Optodist comes supplied with the SR3 optocoupler but is also designed to handle the SR2 version. SR3 givies a tighter, snappier CV response and have less bleed through of the signal when gain is fully off and signal in is set to low settings for a somewhat clean signal or with a lighter distortion. Please note that due to the nature of the vactrol-style optocouplers, response behaviour may vary between different factory batches.
Also on board is an LED based limiter circuit which limits the signal thru a set of 4 LEDs which can be seen on the panel, for adding a different flavour to your distortion. Experimenting with different types will affect the sound.
The Optodist Kit is a novice-friendly project, it is a low part count, single-PCB build that only requires the most basic experience in PCB soldering and module assembly. 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
Download assembly manual here.
Basic specifications
Width: 6hp
Depth with power cable attached: Less than 35 mm.
Power: +/- 15 mA
VC Sequencer
Download assembly manual here.
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.
Final measurements: It can keep sync well above audio rates, with a low jitter 50% PW and 0-5V clock source it can keep sync up to ca 40kHz clock signal. Overall latency is ca 10us (0.01ms) until the step changes + up to ca 10us (0.01ms) to change the volt (bigger change = longer time). Other waveforms and amplitudes can be used at lower frequencies as long as the waveform at least crosses over slightly more than the whole schmitt window between 2.3-2.5V, all inputs can handle the full power supply range.
CV adressing mode is significantly slower as it was in the prototype too.
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. One more change was made to reduce clock latency by 5us.
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 +- the schmitt window.
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, there are connections between PCB's and one resistor need to be modded onto the board, this step is removed in version 1.3.
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
Download assembly manual here.
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
Trig Xpander (for VC Sequencer)
Download assembly manual here.
Introducing the first official channel expander module for the VC Sequencer, the Trig Xpander.
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 coming soon: @Grayscale
Download assembly manual here.
Basic specifications
Width: 4hp
Depth: 45 mm
Power: +12 mA / -0 mA
Ampmix
Download assembly manual here.
Out of production, new version coming.
Vertmix
Download assembly manual here.
Out of production, new version coming.