Tag: VCA

Erica Synths Dual VCA II – DIY Build

Erica Synths Dual VCA II - DIY Build

Completed Rear - Dual VCA II

On with the build....

Fresh off the build table comes Erica Synths Dual VCA II. The module itself is apart of the open source DIY kits that are available via the Erica Synths Github.

Our friends over at Synthrotek have painstakingly taken it upon themselves to part out these kits and package them up to make them accessible by all DIY enthusiasts. VCA’s or voltage controlled amplifiers are modules that every rack contains.

This module is a Polivoks-inspired VCA that is 35mm deep, skiff friendly, has solid mechanical construction and doesn’t require wiring.  Who could pass this one up? We couldn’t! 

In the end, the Erica Synths Dual VCA II is like all other kits in that the BOM is comprised of the basics … resistors, diodes, capacitors, pots and jacks. There might be a few other surprise components in there, but all in all, these are what make up the kit.

Start by laying out all of the components and the x3 boards. This kit contains a control board and a logic board so you will be going back and forth between the two boards when placing components. Resistors, diodes and ferrite beads are first up.

Diodes have polarity so prior to tacking these down, you have to make sure they are placed in the correct orientation. We used top down soldering to make quick work of these. 


Waveform Magazine Meow Mixer (Project 6) – DIY Build

Waveform Magazine Meow Mixer - DIY Build

Completed Meow Mixer - Front

Every quarter we receive a new issue of our favorite magazine… Waveform. In this issue (Summer 2021 – Issue 6), a small 2HP module called the “Meow Mixer” was featured alongside a new modular case kit (aka. The Mewsic Box) as the featured project. The Meow Mixer is a 3-channel powered Eurorack module that has 3 inputs with attenuation, and 1 summed main output with an output volume control.

As with every DIY project that Waveform Magazine releases, the Meow Mixer was unique in that it could be used in conjunction with other DIY projects that Waveform released. This sounds confusing we know … but stick with us on this build and we will explain everything in detail. So, without further ado, let’s jump right into the build of the Waveform Magazine Meow Mixer!


Waveform Magazine Catwalk LPG/VCA – DIY Build

Waveform Magazine Catwalk Cattenuator - DIY Build

As we tackled the Waveform Magazine Cattenuator, it was now time to tackle the new LPG/VCA. Like the previous build and the Mini Mult Catwalk, these modules take up about 12HP of space in your rack. Their footprint is small and their impact is huge. As previously stated, Waveform Magazine is on point with their Catwalk series. In case you have missed any of the previous builds or reviews, check out the quick links below to learn more.

Project #5 - Catwalk LPG and VCA

Let’s get onto the builds shall we? Building the Catwalk VCA or the Catwalk LPG is relatively easy. The most difficult part of this build is assembling the vactrol or optocoupler as its sometimes called. An opto-isolator (also called an optocoupler, photocoupler, or optical isolator) is an electronic component that transfers electrical signals between two isolated circuits by using light. 

You will be putting together 2 of the optocouplers for this set of Catwalks, so turn on your iron and get ready to dive right in. 

Quick Links:


Waveform Magazine Cattenuator – DIY Build

Waveform Magazine Catwalk Cattenuator - DIY Build

Issue #5 of Waveform Magazine is hot off the press and is steaming with all sorts of amazing modular goodness. With its reviews, interviews, industry news and modular kits, it is no wonder that so many modular enthusiasts look forward to each issue.

Since the magazines first release, we have been building the WF kits as soon as we get our hands on them. Here are the previous projects that Waveform has released and we have had the opportunity to build/review.

Issue/Project #1: PT2399 Delay

Issue/Project #2: The Gateway Oscilloscope 

Issue/Project #3: The Switchenator 

Issue/Project #4: Catwalk – Mult, Mini Mult and Ribbon 

Project #5 - Cattenuator!

As with all of the previous builds, the quality and the ingenuity continues to get better and better. Waveform really threw everyone for a shocker with their “Catwalk” series from Issue #4, being that neither of the projects took up any space in ones rack (hence the name “catwalk”).

Issue #5 is no different and we are fortunate to have another x3 Catwalk modules (actually 4, the Catwalk Attenuator contains x2 of the same modules). With all that being said and done, let us get on with the builds so you too can see how cool these new Catwalk modules are! If you would like to bypass and jump to a specific Catwalk module, use the quick links below.