Erica Synths Polivoks Envelope Generator - DIY Build

With October coming to a close, we decided to take on one more build for the month. This time we took on the Erica Synths Polivoks Envelope Generator kit by Synthrotek. We were lucky enough to get our hands on one of these modules being that the recent supply chains have been challenged. 

Many of the DIY kits are either sold out or components have been scarce. Upon getting the kit, we took a moment to review the BOM and Assembly Guide provided by Erica Synths and dove right in upon receipt of the kit.  

Diodes and Ferrite Beads

There are several types of diodes included in the kit. Start by identifying and separating the parts so that you can easily install them in the correct orientation as according to the PCB. If you have any issues trying to figure out how to mount the parts, refer to the board layout visuals that are included in the Assembly Guide download.

After the diodes have been installed, grab the two ferrite beads and install these. They have thicker legs on them but they mount like any other component. Just take your time and solder thoroughly. 

Caps, IC Socket and Power Header

There are not a lot of capacitors to install, so start with the ceramic ones first. Their orientation doesn’t matter so you can place and tack and move on. The electrolytic caps have an orientation and you want to line up the white line on the silkscreen with the negative or white line on the part. 

Next up is the IC Socket and power header. Since these are tricky pieces to flip a board on, we recommend that you place a dab of solder on one pin, adjust and complete. You can also use a jack or something to hold the board in place when soldering the 10p power header. Either way you decide, just make sure that the piece is seated correctly and that it is flat against the PCB.


Seems odd we took care of all the other parts before we got to the resistors. Usually the resistors are some of the first parts we place in our build order. The resistors in this kit are laid out on a piece of long tape and for the most part are in order of the BOM. Sometimes parts can shift around when they are packed so double check your parts prior to placing them. 

You will also want to mount these resistors vertically and some of the mounting points are not used or labeled NU. Do not place anything into these mounting points. We recommend mounting the resistor, then tack down the “free” leg, then flipping the board and completing the part. 

The one thing you want to make sure and do is take your time and refer to the BOMs or visual aids provided in the build file. After you complete the resistors, take a break and come back to the transistors later.

Transistors and LEDs

The kit contains a lot of transistors and placing these and soldering can be somewhat difficult. Take your time here and solder one pin at a time if you have to.

Being that the pads are so close to each other on the board, you can easily have a solder bridge and it could short the board. This isn’t the case if you take your time and jump from pin to pin not applying a long time of heat on the part. 

As for the LEDs, the red one mounts on the top of the PCB and the yellow mounts on the lower point. You will simply just place these parts (mind the orientation/polarity) into their pads and not solder them yet. You will solder these into their final resting places after we place the front panel. 

Erica Synths Polivoks Envelope Generator -Time Lapse Build

Play Video

Switch, Jacks and Pots

Place the switch into its place and then move on to the jacks. Set the jack into its place and tack down the ground leg to help hold it in place. Do not solder any of the other legs right now, that will happen at the end of these steps. Next up are the pots. Make sure you check the pot values prior to placing the pieces. There are two different types of pots in this kit.

When you have everything in place, set the front panel on the top of the jacks/pots/switch. Hand tighten a few nuts on the front to keep the panel in place as you flip the board over to solder the rest of the legs. You can also tack down the LEDs at this point, ensuring that they poke through the front panel prior to soldering. 

Erica Synths Polivoks Envelope Generator - Buiid Gallery

Wrapping it all up…

Finally you are at the end of the build and there is only a few things left to do. First up, place the rest of the nuts on the jacks and pots. We used our Synth DIY Tool Set to make sure everything was in place. When this is complete, line up the knobs and place them on their final resting pot and tighten them down. Make sure you pop in the IC before powering up the module and if we recommend using a Synthrotek TST module to make sure you have everything soldered correctly. (If it smokes, thats a bad thing). Now pat yourself on the back … you have completed the Erica Synths Polivoks Envelope Generator module (say that 10 times!).

fin Divider

Erica Synths Polivoks Envelope Generator - Purchasing Options

Synthrotek offers a several options when it comes to purchasing the Erica Synths Polivoks Envelope Generator. Their prices are excellent and the quality of this build is way worth it! If you are interested in buying the kit, the assembled module or just the PCB/Panel/IC, click on the images below and you will be redirected to their site to purchase! Make sure and tell the gang at SR that we sent you!

Our Final Thoughts . . .

Upon completing the Erica Synths Polivoks Envelope Generator, we have to say that this is a build for intermediate builders and not recommended for new or novice builders. This module has some close quarters when it comes to soldering. LEDs and transistors can really be a bear if you are not used to having a steady hand. Have your desoldering tool handy if you need to as well.

As for the module itself, its really a basic ADSR and there is little that one can do to “mess” things up when using it. While we haven’t spent a lot of time with the module, we know that modules like these are used very frequently in performance or recording. Make sure and pick one of these up and if you are down for a kit, get one soon as the supply chain is getting more and more limited. 

Comments or Suggestions?

If you have questions about the build process or suggestions/feedback about this article, feel free to let us know by contacting us  We look forward to hearing from you!

Until the next build … 

~ f i N

fin Divider