Tag: synth DIY

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. 


Erica Synths Output – DIY Build

Erica Synths Output - DIY Build

As the world of modular continues to grow, there is one module that is a must for any rack or system…. the output module. How else are you going to get your amazing performance to your speakers or interface to record? 

Erica Synths have been around a long time and their eurorack kits give DIY enthusiasts a chance to build their amazing modules. Their open source modules were previously discontinued and hard to come by until recently.

Packed and distributed by Synthrotek  the entire DIY line of modules is now available for you to take on! The Erica Synths Output module is a quick and easy build and is an essential module for any system. 

Before we jump right in...

Erica Synths Output - Completed Front

Since you are dealing with two PCBs on this build, we highly recommend reading the assembly guide when you are putting this module together. Things can get tricky because there are multiple things going on here.


Erica Synths Modulator II – DIY Build

Erica Synths Modulator II - DIY Build

Completed Front - Modulator

Following our last build of the Erica Synths Mixer II module, we decided to go back to back by taking on the Erica Synths Modulator II. This DIY module is essentially an LFO with simultaneous triangle and square wave outputs. It is a clockable S&H module with external CV input and noise source. It is also one of the new kits currently being offered by the gang over at Synthrotek.

Apart of the DIY series from Erica Synths, the Modulator II is unique in that it not only has one noise source, but two. Noise sources come in the form of “backpack” PCBs that one can swap for different tones of noise. You have the choice of transistor-based or Zener diode-based noise generator for massive, full spectrum white noise.

As you start this build, it can easily feel overwhelming upon cracking open the kit being that there are multiple PCBs and a bunch of components. Synthrotek did a great job on this kit by providing a clear BOM which we have scanned and linked below. They also separated all of the components for each backpack PCB so that the parts could be located quickly and partnered with the correct board.

IMPORTANT: Before we jump into the build, take note that this is not a build for novice builders. This is due to the very tight soldering pads, poor layout of the silkscreen and one’s ability to read a BOM. You do not want to go into this build not knowing how to read or build from a BOM, being that there is little to no step by step assembly instructions.

The Erica Synths assembly guide is really generalized compared to most DIY build guides we have seen from other companies (but hey, thats why we are writing this up and recording our videos).


Erica Synths Mixer – DIY Build

Erica Synths Mixer II - DIY Build

The Erica Synths Mixer II is part of the DIY series that are now being offered by Synthrotek. Of course, when we heard this, we had to reach out to our friends in the shop to see if we could get irons this kit. A couple of weeks later the kit arrived and we anxious to get it into the shop and in our rack.

So what exactly is a mixer…?

A mixer is literally just that. It mixes whatever you put into it into something with all parts combined. We know how simple that sounds, especially if you think of it like cooking or baking terms. A mixer, mixers the ingredients together to make something else. 

Erica Synths simple describes the Mixer II as a “simple, straight-forward audio mixer” and that the Mixer II is an “essential part of any modular setup.” This is where Erica Synths could not be more correct. A mixer is an essential part of any music recording whether it be via a studio rack, performance rack or recording console (aka. mixer); you need it to mix your ingredients into something else.