Notes: The LPG is a West Coast Synthesis staple! The dual Low Pass Gate creates organic percussion timbres, paving the way for sonic exploration with a Buchla/Subotnick vibe.
The LPG has two low pass gates in one module. Its unique non-linear qualities emulate percussion timbres like congas, bongos, plucks, etc. The LPG is vactrol based, which creates natural-sounding decays. When the CV input is pinged by short/fast envelopes, it results in more organic sounds like bongos. The slide pot functions in two ways: when the the CV input is not patched, it attenuates/mixes the audio signal. When the CV jack is patched, it attenuates the output level and changes the timbre of the audio signal.
Each LPG channel can be used as a VCA. VCA mode bypasses the low pass filter and resonance and doesn't color the sound of your input audio. The vactrol gives the VCA a living, breathing, non-linear response.
A number of vactrols were tested for this module, and the pre-tested NSL-7053 yielded the most positive results. The NSL-7053 has a slower response and a more exponential response curve. The VTL5C4 has a slightly faster response and a more linear response curve. Vactrols have a lot of variance, so even if you use the same vactrols for both channels, each channel may sound a little different. But the LPG will work with a number of different types/brands, including dual vactrols. In fact, each channel can be built with a different set of vactrols. (Note: VTL5C3 and VTL5C3/2 vactrols are not recommended in the LPG.)
Notes: The VCO is an analog voltage controlled oscillator with a wide frequency range and 8 trackable octaves. It uses the Curtis CEM3340 reissue chip, which is famous for its outstanding sound quality. This is the fully assembled version of the VCO.
Notes: Synthrotek's FOLD is a combination Wavefolder and Ring Modulator. The FOLD changes the shape of a waveform in order to create harmonics and find new timbres and sonic palettes. The Ring Modulator circuit mixes two waves together to make metallic, bell-like tones, big bass lines and Dalek sci-fi robotic sounds. Patch your folded wave into the ring mod (or vice versa) for sonic euphoria!
Module width: 4HP
Module depth: 60mm
+12V: 50 mA
-12V: 40 mA
+5V: 0 mA
Notes: The 1U Mattson Buffered Multiple is a PRECISION buffered mult that is perfect for 1V/O CV sources. A signal plugged into INPUT A will be available from all 8 OUTPUTS. Break the chain by adding a second signal into INPUT B; signal A comes out the 4 "A" outputs and signal B is available at the 4 "B" outputs.
Please note: Synthrotek's 1U products do not fit in Vermona or Intellijel cases.
Current draw: +12 18mA, -12 18mA
Notes: The Synthrotek Verb is a reverb module like no other. This PT2399 unit offers a warm tape-saturated spring reverb sound, but the added flair of subtle modulation truly makes it shine. The input gain knob drops the input amount back to give cathedral-like sounds when the mix is high. Turn the modulation knob manually for pitch bends; patch in a slow LFO or envelope CV to emulate pitch bends reminiscent of a tape echo with a broken capstan. The mix knob is a very fast-responding cross fader circuit which allows audio rate inputs for further FM-like modulation. Add a subtle amount of reverb or crank the mix past 3 o'clock to knock the reverb signal into the rails.
Notes: Arcadian Rhythms is an arcade button module that can be used to trigger drums, envelopes and other events in a Eurorack system. When the buttons are pressed, they light up and send a gate. As long as a button is held down, the gate remains high.
Mix and match your LED buttons! The brightness between colors will vary slightly, but the trimmers on the back of the module will adjust the LED brightness so the three buttons match. Reducing the brightness will also reduce the current draw (each button draws 41mA at full brightness).
Choose red, blue, green, yellow or white buttons.
Module width: 35mm
Module depth: 6HP
Current draw: +12V: 123mA max (41mA per button)
Notes: DIRT is our new 4HP low-pass filter / effect for the Eurorack modular synth platform.
The DIRT is an unapologetic filter / effect that produces interesting and unique effects via the Bias knob, accessible from the front panel.
It's not a traditional filter; it's an effects module with filtering, ring mod effects, wave shaping and even outright brutal harmonic distortion.
DIRT likes to square things up a bit, so throw in a triangle, sawtooth, sine or other wave forms for different style effects. Even plugging a guitar (using an external amplification module) into the DIRT produces some great sounds and heavy distortion.
- CUTOFF = Cutoff Frequency
- RESONANCE = Increase the Q!
- BIAS = Set the bias correctly or not, the choice is yours
- Version 2.2, which as a buffered CV input jack. CUTOFF CV IN = Voltage range changes depending on where CUTOFF knob is positioned. External attenuation will be needed for fine modulation.
Notes: The M/DIV is a CV-controlled dual clock multiplier/divider with tap tempo, ideal for complex generative patching, sequencer timing and unique rhythm generation. The M/DIV has three clock outputs: a master clock and two multiplied or divided clocks. Each channel can do either multiplication or division with the flip of a switch.
Notes: OBEY is a dual-function module: one half envelope follower and one half attenuverter / offset generator.
The OBEY takes an audio or CV signal and uses it to trigger an envelope or gate for use in a Eurorack system. It is designed to work with a wide variety of input levels: plug a Eurorack module, passive microphone, piezo, guitar, drum machine, Game Boy into your Eurorack system.
Attenuverter / Offset Generator:
Attenuvert your voltage sources up to two times in the positive or negative! The offset generator provides up to 5 volts in the positive or negative.
Notes: This simple passive mixer is suitable for mixing both audio and control voltage sources. Three channel inputs mix down to one output.
It is not suitable for additive voltage applications. All the jacks are switched to ground to minimize external interference when not patched. This can lead to unwanted attenuation of the output signal unless you plug a dummy cable into the unused channel(s) or, even easier, you can turn the channel's pot completely CCW.
Power consumption: none
Module screws included
Notes: The Synthrotek Power Pak converts the power in your Eurorack case to 9V, 12v, and 5V USB. You can easily power guitar pedals, drum machines, controllers, USB lights, charge smart phones, and other devices without having to lug around bulky power bricks. Just plug a male-male connector cable (2 included!), daisy-chain cable or USB cable into the Power Pak, and you're good to go.
Need to add +5V to your existing power supply? By installing one jumper, the Power Pak allows you to add +5V to your power distribution board or bus cable. This can be used to power Eurorack modules that need +5V.
Keep it simple and tidy with the Synthrotek Power Pak!
750mA limit on 9v and 12v barrel jacks
1000mA limit on 5v USB jacks
DC jack size: 5.5 x 2.1mm
Notes: The Octave Fuzz is SynthRotek's take on the classic 70's SuperFuzz circuit, made into a Eurorack module, which has improved on some aspects of the original as well, including an increased output.
Two distinct voices like the original: switchable between scooped midrange and massive midrange bump.
Aggressive: It will sound massive and in-your-face like no other circuit can. This is for sonic explorers and heavy music only. In short, it's not useful for EVERYTHING, but the things it DOES do it excels at. Sounds especially killer for keyboard and bass sounds.
Tuned to give a subtle distorted waveform one octave up via wavefolding (see the video to view this on an oscilloscope). (Completed modules come pre-tuned; there are calibration instructions at the end of the assembly instructions for the kits)
This circuit has been optimized for Eurorack. You can find a guitar pedal version here.
Notes: The Synthrotek Passive Mult is the module that keeps on giving! Use this as either a 2x 1-to-3 passive multiplier or one 1-to-6 passive multiplier. Input one cascades to all 6 output jacks, or can be interrupted by plugging a cable into input two.
What is a passive mult? It is an ideal way of multiplying non-precise voltages in your Eurorack system. (Buffered multiples like the MST '07 Buff Mult are needed to maintain exact outputs of input voltages). Multiply any control voltage or audio sources across your system with ease in a very small and well priced package.
Available as an assembled unit, kit or PCB/panel combo. With such a small part count, this is a great module for first-time DIYers!
Current draw: n/a
Notes: The Quadrangle is quad cascading triggered envelope generator with bipolar output attenuversion. Each channel has voltage control over attack and decay/release, end of attack and end of cycle trigger outputs, and mode (AR, loop and AD). Each channel's EOC is normalled to the next gate input, resulting in interesting rhythmic opportunities. Channel 4 has a "stop" or "continuous looping" switch which allows either a "one shot" cascaded envelope or continuous cycling. The SUM output allows for longer and more dynamic bipolar envelopes, perfect for interesting modulation. Users also have voltage control over all of the attacks and decay/releases simultaneously when using the ALL A and ALL D/R input jacks. Massive function generation, modulation, rhythm and versatility sets the Quadrangle in a class of its own.
Module width: 20HP
Module depth: 15mm
Comes with power cable, 2.5mm and 3.5mm screws
Notes: This handy module is a feature rich random voltage generator that is shallow and super powerful. It outputs random voltages (similar to a sample and hold) in time with either its internal clock, or with an external clock you can patch in. An external clock will bypass the internal clock, and the CV jack over the clock, so your random voltages will always be in sync with whatever you patch in. With CV control over both the clock speed and the range of your output voltage, you could create anything from a wildly fluctuating blur of notes all the way to a slow, lilting tune. The RND can also be used as a clock source with it's clock out jack.
Note: due to the voltage drop of the LED in the slide pots, the Range LED wont light up unless the output voltage is above 2v.
16mA @ +12v
0mA @ -12v
0mA @ +5v
Keyed power cable.
2.5 and 3.0mm rack screws.
Super cool sticker.
Notes: Get ready for the bright lights of the colosseum!
SynthTotek have taken the rock-solid RAT clone, squeezed it into a Eurorack module and added CV control over Gain. The 308 will take your playing to new heights with tremolo and other distortion modulation techniques.
Notes: The Synthrotek ADSR is a small and simple envelope generator with some very useful features. CV is additive for overall length of ADR stages in ADSR mode and add even more length to just the Release stage by adding CV into the Release jack. AR mode allows for snappy to long dynamic rhythm lengths. Very short minimum lengths, self cycling and a maximum output of 5 volts makes this tiny (4HP) envelope a very feature packed and versatile module.
Notes: Here is the Atari Punk Console in Eurorack form! Originally designed by DIY electronics guru Forrest Mims III as the iStepped Tone Generator, the Atari Punk Console is one of the most famous and recognizable Lo-Fi synth circuits ever. Using a single 556 dual timer IC with minimal part count, the Atari Punk Console circuit is a solid, time-tested noise generator capable of outrageous square wave madness!
Control Voltage (CV) input allows step sequencers and waveform generators to expand the sonic capabilities of the Atari Punk Console from drone to arpeggio-like dynamism. Use any variable voltage source from 0-Supply Voltage for some glitchy goodness! The APC modular version has two CV inputs that modulate the two square wave internal oscillators.
Notes: The 1U Unity Gain Mixer adds input signals together and combines them for a summed output. For example, if you put in a 1V source and a 3V source, the output will be 4V. It's mainly used for CV, but it can be used to combine audio signals together.
A unity gain mixer is handy in several ways:
Combining gates and triggers. Plug a few sequencer steps into the unity gain inputs, then run the output to a drum synth, VCA, envelope, etc.
Re-shaping two CV sources with a single envelope
Combining different wave shapes or LFOs to make crazy sounds.
Controlling the CV of one source with the CV of another source. Just plug the CV out of a sequencer into and an expression pedal/touchable CV out into the unity gain inputs.
18 mA +12V
18 mA -12V
0 mA 5V
Depth: 32 mm
Please note: Synthrotek's 1U products do not fit in Vermona or Intellijel cases.
Notes: The Synthrotek DLY is a PT2399 bucket-brigade delay module. The PT2399 IC delivers warm and lush analog-sounding tones (the IC is partially digital). The DLY is similar in tone to our ECHO Eurorack module, but its features make it unique in its own right.
Unlike the ECHO which always has a wet signal (i.e. the output is always mixed in with the input), the DLY offers a true wet/dry Mix knob. When the Mix knob is fully counter-clockwise, you get a dry signal. When it is fully clockwise, you get a fully wet signal. This allows the user to plug this delay into effects loops. Also, the DLY allows for CV over Feedback and has an internal Feedback amount trimpot for precise adjustment.
Another added feature is the delay Rate range internal trimpot, which allows you to dial in the delay range of your choice. Turn the Rate knob all the way up to get the extreme, chaotic sounds of an over-clocked PT2399 chip.
Notes: The ECHO (formerly known as the EKO) is a compact voltage-controlled echo/delay comes in the very tidy size of 4HP and is certain to be one of the best bangs for your buck.
A very unique echo using the PT2399 IC featuring Voltage Controlled Rate. Manual controls for Rate, Feedback, and Mix. Beautiful and bizarre, CV modulation of the rate brings in ghostly pitch bent sounds to metallic reverbs. An effects module that everyone needs in their rig.
ECHO Rate CV accepts -5 / +5 voltages (although the negative range is almost -7)
ECHO Rate knob is setup to push the chip into extreme territory and will extend past the "useable" range of the PT2399 IC, meaning that once you turn the knob past 3 o'clock or so, the chip will stop operating and you'll only hear your dry signal.
Attenuation, attenuversion, or using an offset will greatly help when running voltages into the Rate CV input. This way, you can tailor the modulation as you see fit. You will absolutely get the most out of your ECHO by using modules that attenuate, invert or offset your signal.
Notes: Synthrotek's original Mean Screamer Pedal goes way beyond a typical tube screamer clone with a couple of great mods. An original 4558 OP-AMP IC has been used to give it that beautiful classic boost.
Notes: The MIXIV (mix 4) is a four-channel mixer in 4HP, fully built and ready to patch! Channels 1 & 2 can have their own output when a cable is patched in to the sub-output jack. When the left-hand OUT jack is not patched, all channels come out of the right-hand OUT jack. Mix CV or Audio simply and with slider precision! Very skiff friendly at only 26mm deep!
Notes: Low pulsing drones, dive bombs and high-pitched laser sounds! This drone monster has six square wave oscillators with a delay, essentially combining two 4093 NAND Synths and one Cosmic ECHO.
The Nandamonium has two SAG CV inputs. When the CV jack is patched and the switch is toggled to "CV," the NAND circuit is powered directly by the incoming voltage. Beyond controlling pitch, the incoming CV can also be used to create lofi rhythmic effects.
Notes: Need a vocoder, pitch shifter, speak-n-spell effect, vibrato, 8-bit modulator and a bit crusher sounding module all in a lo-fi heavily CV controllable package? Well surprise! we read your mind! The Roboto module is all these and more (and it has a neat Cylon looking graphic that lights up).
Vibrato toggles on and off. Works in either Robot mode or Pitch mode.
Robot and Vibrato CV inputs activate those modes (and deactivates in the case of vibrato) upon receiving a gate pulse. Gate pulses in these inputs are just like pushing their corresponding buttons. Expected transition is from 0V to +5V (and back to 0V), but it will handle any voltage within the power supply range without damaging the module. Transition between what is considered "off" and "on" is at approximately 2.3V.
Notes: The 'Sequence 8' analog 8-step sequencer is a traditional 8-step sequencer with some extremely handy features. It's available in 2 formats: Eurorack or 9V battery/wall wart (the kit version has a FRAC power option).
Notes: Test your modules safely without reaching into your case! The TST has two keyed 16-pin headers on the front of the module so you can plug and unplug quickly and easily. Two 16-pin plugs are included to shield the power pins when the module is not in use. It also has LEDs to indicate the power status on each rail.
Please note: Use this module at your own risk. You will be exposing electricity to the front of your modular system. Be careful not to dangle patch-cables, etc. on the exposed pins. This may damage modules and your power supply. Be smart and safe!
Features and Specifications:
Two 16-pin connectors and plugs on the front side of the module
LED indicator for each rail
Module width: 3HP
Module depth: 5mm
Includes keyed power cable, 2.5mm and 3mm screws
Notes: The 4093 Chaos NAND Synth, in Eurorack form! The 4093 Chaos NAND Synth is a super-modifiable noise generator that will knock your socks off with its sonic potential: low pulsing drones, random robotic chaos, and high-pitched laser sounds!
A great project to begin your explorations into the world of DIY sound synthesis, the PCB was designed with the beginner in mind. Board-mountable switches, socketed IC, hands-on knobs and switches for tone control, and a detailed silkscreen PCB to help you solder components right the first time.