Synthrotek Sequence 8 - DIY Build

Seq 8 - BW Snazzy

For our first DIY build of August we are taking on the Synthrotek Sequence 8, a classic sequencer with an easy to use interface. If you are like us, you know that the heart of any modular system consists of two key things; clocks and sequencers.

Clocks are important because they tell the sequencer or modules at what pace to send a trigger or gate. A clocks counterpart, the sequencer controls at what point the gate or trigger is sent to the corresponding module (ie. drums, percussion, oscillator, LFO, etc). 

These give modular music their rhythm and flow. Without clocks or sequencers, your modular performance would just randomly trigger sounds and it would sound like a train wreck.

We needed to add another sequencer to one of our racks, and after doing research the classic interface of the Synthrotek Sequence 8 just made sense. The Sequence 8 is described as an “analog 8-step sequencer that is a traditional 8-step sequencer with some extremely handy features.”  We knew it was what we were looking for and therefore, we ordered up a kit and we were well on our way. 

On with the build…

The Sequence 8 DIY kit consists of x2 PCBs and x1 Panel. There are a lot of knobs, pots and jacks to go along with the kit, so don’t get overwhelmed by that. Along with all of the aforementioned are LEDs, resistors, capacitors, headers, ICs and all the other components needed to assemble the module. 

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To say that this build is for a novice, would be selling it somewhat short. This build is more of an intermediate build in that the size and the time put into the module could be overwhelming to beginners. Also, the fact that multiple PCBs are involved can also intimidate novice builders. This isn’t to say that if you have tackled a few previous builds, this one isn’t much different… it just takes longer since it is larger. 

Upon starting the build, open up the provided visual BOM or locate the one that Synthrotek has on their site. It will be your saving grace while assembling the module. First off you are going to place the resistors and the diodes in their relevant positions. We used top down soldering for these as there is plenty of room to navigate with the exception of a few areas.

You will see in our time lapse build, that you just need to take your time and maneuver the PCB in an orientation that makes the solder pads accessible. Since all the components are taped in order, its pretty easy to just follow the BOM and place the parts. Take note that there are some spots that will be left blank. 

Synthrotek Sequence 8 - Time Lapse Build

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After the resistors and diodes have been placed on the Sequence 8, move onto the ICs and the caps. You will want to leave some space when mounting the caps so that you can wiggle your iron onto the pad. Tack these down and move onto the IC headers. Once these are soldered into place, refrain from placing the ICs. You want to put that part fo the build off until the final steps. Next, place the header pins and the shrouded power header onto the board and then tack those into place. 


By this point in the build, we recommend taking a short break as the build is getting ready to get into the pots, LEDs and jacks. There are quite a few of these components but don’t let that get to ya. Just take one piece at a time and be patient with yourself. After placing all of the pots, switches, buttons and jacks, pay special attention to the LEDs.

IMPORTANT: Note the orientation of the LEDs (long leg goes into the square pad (+) and the short leg goes into the other (-)). Do not solder any of these components into place yet.

Seq 8 - LEDs mounted
Our kit came with red LEDs, but we wanted blue instead. We swapped out our LEDs and moved forward with placing them in the correct orientation

Sequence 8 Build Gallery

Lining it all up ...

Next, you will be placing the panel over newly set components to help line everything up prior to tacking them down. Once you have the parts lined up, use a couple fo the supplied nuts to hand tighten the panel to the PCB. Make sure everything is flush and flip the board over. Solder all of the parts except the LEDs. You want to save them for last as they need to be lined up. We found that it was pretty easy as long as we bent the legs of the LEDs after placing them in their correct position. Once they are place, solder them into place and trim the legs.

At this point in the build you can go ahead and place the other nuts onto the panel if you haven’t already. We used our handy Synth DIY Toolset to ensure that we didn’t scratch the panel while tightening the nuts down. 

Now it is time to marry the two boards. Place your IC’s in their corresponding locations making sure that they are they are in the correct orientation. Grab the smaller PCB and line up the 1/2 and the 19/20 pins on each PCB – this is the correct way to marry the boards. If you mess this part up, it’s no bueno. 

The Completed Sequence 8 Module

Wrapping it all up...

The Synthrotek Sequence 8 came with 14 white Davies 1900H knobs (clones). We decided we wanted to customize our build, so we grabbed our clear Davies 1900H knobs (clones) and began the tedious process of lining everything up when placing the knobs.

Our suggestion is to take one line at a time and alternate the way that you tighten things down. For example, on the top row we turned the pot all the way to the counter-clockwise, place the jack with the black pointer facing the lower left corner. Tighten down the knob. Do this for the entire row.

The next row will be completed in the opposite manner. (ie. turn the pot to clockwise until they stop, place the knob with the pointer facing the lower right) By alternating back and forth on the rows and you will have the ability to easily get to the brass insert screw to tighten things down.

Calibration and Testing...

You are now ready for testing and calibration of this awesome sequencer. Prior to racking our Sequence 8, we used our Synthrotek TST module to ensure that we had all of our connections placed correctly. This is so that we won’t fry our rack.

Although we knew were good to go, it is always a safe bet to do this. Everything powered up as expected and we were now onto calibration. To make things easier, we put together a PDF file from the bottom of the Synthrotek Sequence 8 Assembly guide for quick access (see quick links).

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Features and Specifications


  • 8 Steps with high-gate output per step
  • 3 CV Outs, each with their own attenuator, 0-5 volt output.
  • Clock Input and Output
  • Coarse & fine clock adjustment
  • Switchable linear ‘random’ function with speed adjustment
  • Momentary & Hard Hold Function
  • Manual Step Button
    Internal/External Clock Switch
    Reset Input Jack


  • Power supply: +/- 12V 
  • Power connection: Eurorack uses 10-pin shrouded header.  9V battery/wall plug for FRAC or Standalone 
  • Current draw: 25mA (+12V) / 18mA (-12V) / 0mA (+5)


  • Module Height: 3U
  • Module Width: 20HP
  • Module Depth: 1.5 inches (EU & FRAC)
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Sequence 8 - Purchasing Options

Synthrotek has a couple different options when it comes to purchasing the Sequence 8 module. We wanted to keep it simple by just placing images of the options and linking out to the direct purchase. The prices are excellent and the quality of this build is way worth it! Head on over to SR and tell them we sent ya!

Our Final Thoughts . . .

As of the timing of this review and build guide, we haven’t had a lot of time to play with the Sequence 8. It is very simple to use and the momentary and hard hold buttons are a couple of our favorite features. These lock the sequence in place so you can change up your performance on the fly. Hard hold will hold the signal until you release it, whereas the momentary will stutter the signal and move onto the next. Pretty cool if you ask us.

The basic aesthetics of the Sequence 8 fit along with the black/white panel and knobs that Synthrotek is know for. With any module, you can customize the way it looks by changing out knobs and in our case even the LEDs. Our clear Davies 1900H clones along with the blue LEDs really stand out amongst our other modules. It just looks sleek. We look forward to pairing this sequencer with Pamelas’ New Workout or our 4MS Clock Dividers and you can guarantee you will be hearing and seeing this module used A LOT.

For a classic analog step sequencer, the Synthrotek Sequence 8 is a no brainer to have in your rack. We might even have to pick up another just to chain them together.

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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