Tag: envelope

Synthrotek Quadrangle – DIY Build

Synthrotek Quadrangle - DIY Build

The Synthrotek Quadrangle is a quad cascading triggered envelope generator with bipolar output attenuversion and is 20HP module with a lot of versatility. With 4 cascading envelope generators and user voltage control over attacks and decay/release, this module is in a class all to itself. 

As the fall season slowly began creeping in, we decided to go back and see what kits we had left to build for the year. To our surprise, we totally forgot that we had the mysterious Quadrangle from Synthrotek up on our build wall. This was partially due to the studio remodel and the continuous go go go of daily life. 

The Kit...

When we opened up the kit, the first thing we noticed was the size of the boards. This was a BIG module. 20HP to be exact. It consisted of 2 PCBs and one panel. We ordered the kit with the black panel but Synthrotek also offers a silver panel. As this kit was a big one, we knew we where in good hands with the amount of build data there would be available.

Included in the kit was a printed BOM as well as all the components you need to complete the kit.

Intermediate to advanced builders will not have an issue with this build, whereas novice builders could struggle due to tight soldering pads. 


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.


Synthrotek VCO – DIY Build

Synthrotek VCO - DIY Build

As you get more and more involved in the modular world, you will hear the statement “you can never have enough VCO’s” We have found that this statement is very true and it was time to add another to our rack… the Synthrotek VCO from their slider series of eurorack modules. VCO’s or otherwise known as Voltage Controlled Oscillators are a must have for any modular artist as they are often used for drones or other audio sources.

Compact and backed by the Curtis CEM3340 reissue chip, the Synthrotek VCO is an analog voltage controlled oscillator with a wide frequency range and 8 trackable octaves. Let’s get onto the build…

The Build...

One thing you will notice with the Synthrotek VCO kit is that it is a partial kit and not a full on DIY kit. A “partial” kit usually means that most of the tiny stuff has been already soldered and you only have to solder the bigger hole-through components; this kit is just that.

Please note …. this doesn’t mean that the kit is for beginners though!