Dreadbox Lil Erebus - DIY Build
Rewind 4 years to Superbooth 2018 as the production of the Dreadbox Erebus analog synth ended and the world was eager for its replacement. Superbooth was the perfect time for Dreadbox to introduce their latest DIY module the Lil Erebus. Being that this was a replacement for the beloved Erebus, these kits went fast and instantly became hard to find.
We scoured the internet for months trying to locate a kit in the summer of 2020 and they were so few and far between. Luckily, we clicked on the right link one day and found one of the kits at Robotspeak in San Francisco, CA. After a few quick clicks to pay for the module, we were excited to get our hands on it about a week later.
What is the Lil Erebus?
The Lil Erebus consists of two oscillators, a 2-pole low-pass filter, an envelope generator (ADS), an LFO and the excellent voltage controlled echo effect. It also features 16 patch points that allows you to use it with your modular gear.
At 42 hp, this paraphonic synthesizer was quick to become a heavy hitter in our rack due to its unique capabilities and heavy oscillators.
The Build ... Resistors
One thing you will notice right away is that the kit is packaged nicely and it is easy to find all of the parts you need to start the build. Since there were 121 resistors, this part of the build took the longest.
Take your time locating the correct mounting holes for each resistor and since they are not polarized, you do not have to worry about their orientation. We used top down soldering to tack everything down and then cleaned up/reflowed wherever it was needed on the back of the PCB. When this was complete, we trimmed the resistor legs and moved onto the diodes and IC sockets.
Diodes, IC’s and IC Sockets
There are very few diodes to install on this build, so this step goes by very quick. Make sure you match the stripe on the diode with the stripe on the silkscreen when placing the component and then solder everything into place.
Flip the board over, touch up and then clip the leads. As for the IC sockets and IC’s, first solder the ICs and afterwards the IC SOCKETS (or buy sockets for every IC if you are not comfortable soldering IC’s directly).
There are quite a few so take your time when doing so. We like to place a dab of solder on the pads and then set the socket on the pad. Next heat up the pad with the solder and gently push on the socket. Once it heats up, the socket will just click into place so that you can tack down the other pins accordingly. When you are done with this step, it is time to move onto the capacitors.
Lil Erebus - Time Lapse Build
The capacitors are up next on the building block. Start with the non-polarized caps and mount them on the PCB accordingly. There are quite a few of these, especially the 24 ceramic 100n caps, so take your time and be sure to place things where they go. When you are done with the non-polarized caps and you have tacked everything down, grab the polarized caps and mount those with the long lead pointed towards the ‘ + ‘ symbol on the silkscreen. Flip the board over and solder everything into place. It’s now time to move onto transistors and other miscellaneous parts.
Dreadbox Lil Erebus - Build Gallery
Transistors and Other …
The transistors are up next and when mounting these you want to make sure you are placing them in the correct orientation. If you are unsure, make sure and double check the PCB silkscreen. Since there are 8 of these, you will want to ensure you are placing the right one in the right spot.
Flip the board over, solder and trim the leads when you are done mounting. Next, place the crystal and the trimmers. Tack these down and move onto the LED. The LED has a socket so you want to be sure you attach the socket to the LED prior to placing it. It’s long leg needs to match up with the positive indicator on the PCB.
Jacks & Potentiometers
By now, you should have soldered everything except for the jacks, potentiometers and the ribbon socket. Take a look at your pcb and make sure that you have completed successfully the previous steps. In case you have any leftover materials, (for example some extra 100n capacitors or resistors), don’t worry and ignore them as these might had been added as extras. Locate and solder the 16 jacks that come with the kit. Make sure you have the correct orientation prior to tacking these down (see the photo for reference).
The slide pots are a core component of the Lil Erebus and it is important to get these lined up correctly prior to placing the panel on the synth. In order to solder easily the slide potentiometers, just solder one at a time and solder one of the leads to help keep them in position, then solder the other 2 leads and press (while heating the leads) the slider. It will click into place and you are good to go. After the sliders, place the 4 rotary pots and solder them into place. If you need to use the panel to help line things up, feel free to do so.
Wrapping it all up…
Locate and solder the 1x 12pin male header and a 4 DIP switch on the backside of the PCB. Pay attention to the orientation of the 4 DIP switch and place it like the photo below. When you have completed this step, place all the remaining ICs into their sockets. Make sure that their orientation is correct. At the same time, screw the 4x 3*6 steel bolts along with their 4x spacers on the pcb. Lastly, place the front panel on the pcb and screw the knobs down along with the 4x small black bolts on the four corners of the device. You have just completed the Dreadbox Lil Erebus. Now it’s time to calibrate this puppy!
Being that you just completed the module, you will want to calibrate it prior to use. If you care less about how in tune the machine is, just skip this part, but make sure to complete the VCA click or you will drive yourself up the wall. The trimmers are located next to the rotary pots under the front panel, so you will want to remove the panel prior to tuning (or do this before you place the panel)
Scale 1 – scales the VCO1 tuning for 1V/oct
Scale 2 – scales the VCO2 tuning for 1V/oct
Tune 2 – sets the VCO2 central tuning
Master Tune – sets the synth’s total tuning
The VCA Click
a) clean: set the trimmer so as when triggering the synth you get the lowest possible click noise, with the mix of the delay set to 0.
b) delay: set the trimmer so as when triggering the synth you get the lowest possible click noise, with the mix of the delay set to full and the feedback set to 0.
Dreadbox Lil Erebus ... Our Final Thoughts
The Dreadbox Lil Erebus is a really cool little synth that required some patience when building. Between the amount of resistors and the amount of time it takes to locate and solder all of them, the build can take some time. Ours was completed in the span of a couple of days due to our busy schedule.
The kit itself is very hard to find these days since it is no longer made and has been discontinued by Dreadbox. We do recommend mounting the module in a rack and to toss the cardboard box that comes with the module. Dreadbox gives you the option of mounting the synth to your liking which is nice, but it is a no-brainer on which mounting option will best support the module.
With regard to the sound of the Lil Erebus, it rivals some of the best micro desktop synths out there. It’s oscillators are rich and beefy and the true character of the module comes from self-patching itself. With all of this being said, it might be hard trying to locate one of these synths, but if you can find one, you won’t regret picking it up…. now, if we could only find the elusive discontinued HADES!
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 …