Division 6 Dual Mini Synthesizer - DIY Build

D6 - Completed Module Close

Division 6 is the maker of unique modular and desktop synths and one of their latest creations is perhaps one of the coolest. The Dual Mini Synthesizer is a two part modular synth that houses two complete synthesizer voices. They are based on the Business Card Synthesizer with all its 8-bit goodness, but adds CV inputs for most of the controls. With that being said, it is also makes the perfect pair partnered with the Dual Mini Sequencer that we built awhile ago.  

Since we didn’t go into great detail on the Dual Mini Sequencer build, we decided to do this one a proper write up and review. Now, enough about all that, let’s get on with the build!

Diodes and Resistors

First up are the diodes. 

Insert the diode into the holes marked D9 on the main PCB. Polarity does matter for diodes, so when you insert it into the board, make sure the black stripe on the diode lines up with the stripe on the silkscreen pattern. If you have these flip-flopped, the module will not function correctly. After placing all of the diodes, use top down soldering and tack everything into place. Flip the board over and reflow anywhere you need to. 

Resistors on the other hand can be mounted either way as polarity does not matter. Once you place these, either flip the PCB and solder or use the previously mentioned top-down method to solder them into place. 

Ceramic Caps and IC Sockets

Next up are the ceramic caps. Orientation doesn’t matter as you place C3-C6. When these are complete, tack them down and move onto the IC sockets. With the IC sockets, you want to make sure you match the orientation outlined on the PCB. You can flip the board over and solder 1 pin to keep them seated in place. If everything is lined up and seated, complete tacking them down wrapping up this part of the build. 

Division 6 Dual Mini Synthesizer - Time Lapse Build

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Regulator, Electrolytic Caps and Power Header

There is 1 regulator on this module and you want to make sure not to keep your iron on it when soldering it into place. Simply insert VR1 into the board, making sure the flat side of the part is lined up with the flat side on the silkscreen pattern. Solder and trim the leads.

The electrolytic caps are next and it is important to pay attention to their polarity. Make sure the (-) stripe is lined up with the – (round) hole on the PCB (and is opposite the “+” marking on the silkscreen pattern). Solder the capacitors into place and trim the leads; it is time to move on. 

While you are here, knock out the 10pin power header that is located at the end of the IC socket row. An easy to place this is to take a dab of solder and fill one hole of the mounting point. Then gently press the component into place by heating the opposite side of the board. If it is seated properly, you will hear a slight “click”. When this is complete, finish up the rest of the pins and call it done. 

LEDs and Buttons

Start by slipping a spacer on LED D1-D8. Insert the LEDs into the PCB and bend the pins outward to hold the LEDs into place. Polarity does matter for LEDs; you’ll notice that they all have a flat side on their package. If the flat side is hard to see, each LED also has a long and a short pin to indicate polarity. As there is quite a few LEDs, it doesn’t matter in what color order you place them, just make sure you match the top synth with the bottom synth. 

You may want to temporarily fit the front panel in place to make sure all the LEDs are straight and line up with the LED holes in the panel. Solder and trim the leads. Buttons are next up and there are 4 of them total. Insert the button switches S1-S4 into the PCB. They fit 2 different ways, and either way is fine. They will snap into place, making it easy to flip the board over and solder them. Make sure they are flat and straight as you insert them. Once everything is lined up, solder the button pins. Note: the pins are short enough that they don’t need to be trimmed.

Jacks and Pots

There are a lot of jacks and pots with this kit. They actually make up the bulk of the kit itself. Start with the jacks and insert J1-J26 into the main PCB, soldering one pin of each as you go to hold it in place. Check to make sure that they are flat against the board and lined up with the silkscreen pattern; reheat and reposition if not. 

Careful with the pots as there are multiple values. R7 and R20 are 1M (they say B105 on the bottom), where all the others are 10k (they say B103 on the bottom). Place the pots in their correct place and temporarily install the front panel to help line things up. You can place a nut on a couple of the jacks to hold the panel in place as you finish up soldering the pots. Once complete, remove the front panel and head onto the next step of the build. 

Division 6 Dual Mini Synthesizer - Buiid Gallery

Dual Mini Synthesizer - Audio Demo

While we haven’t had a lot of time with the Dual Mini Synthesizer, we did want to put together a quick audio demo after we tested everything. In the video below, we use several modulation resources to tinker around with the D6. 

Standoffs and Front Panel Placement

Using 2 silver screws, attach the 2 standoffs so that they protrude from the same side of the board you just installed the pots on. (The holes for the standoffs aren’t labeled, but they have thick silver rings around them). Next place the front panel on the module. Install the hex nuts on all the jacks. Screw the two black screws into the standoffs to hold the top of the panel in place. Flip the module over… 

Features and Specifications


  • Pulse, square, triangle, and sawtooth waves
  • Glide
  • 2 LFOs with pulse, square, saw, triangle and ramp shapes
  • Attack / Decay
  • Low-pass filter
  • Sample and hold
  • Manual gate trigger (can be locked on)
  • 1V/O input with course and fine-tune controls



  • Power supply: +12VDC (reverse-polarity protected!)
  • Width: 18HP
  • Depth: 21mm
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Dual Mini Synthesizer - Purchasing Options

Synthrotek offers a several options when it comes to purchasing the Division 6 Dual Mini Synthesizer. 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!

The Final Step - ICs

Before inserting U1 and U2 into their sockets, you may need to bend the pins inward a bit so that they’ll line up with the holes. Lay each IC on its side on a flat surface, then gently press down on the top of the chip so that the pins bend evenly. Repeat for the other side of each chip. (Or use an IC Pin Straightener like we use to bend the legs properly). 

Insert the chips into their sockets, making sure that the pin 1 notches on each chip and socket are aligned with each other. Both ICs are identical, so it doesn’t matter which chip goes into which socket. It is now time to test the module and power it up. When doing this, we use our spare rack that contains one of Synthroteks TST modules. This ensures that the module is safe for our large racks and tells us if we messed something up or not. We highly recommend this step. 

Our Final Thoughts . . .

Let us start off by saying that the kit was a fun kit to build. It is not recommended for novice builders due to the close proximity of some of the parts. It’s a powerful little module wrapped up in 18hp. Don’t expect to hear clean and pristine sound from the module as it was designed to be a bit grungy and lo-fi. 

With two LFOs, a glide control, a simple Attack/Release envelope and a Sample & Hold circuit, this little module packs a lot in it. Paired perfectly with the Dual Mini Sequencer, it is hard to imagine not having this module. We look forward to spending more time getting to know it better and as you can see from the audio demo, we have only scratched the surface of this amazing little thing. 

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

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