Aaron Hong
All work

Synth Labs · CAD / Hardware

Synth Labs Solo

Prototypes of a IIDX-inspired macropad.

Product page

First prototype

First Solo prototype in silver aluminium on a windowsill: seven keys and a knob.

First prototype - design is a bit different in the keypad area, and only anodized aluminum is used.

The first prototype from above.

First prototype

The first prototype on a wooden desk with a cable attached.

First prototype with cable

Firmware and the hotswap encoder

Testing QMK firmware / VIA support

Showing off the hotswappable rotary encoder on the prototype PCB.

Close-up of the rotary encoder shaft held by a panel-mount nut.

The rotary encoder uses a panel-mount nut, to prevent any play despite being on a hotswappable PCB.

Second prototypes

Three second-round prototypes in different finishes.

Second prototypes - design is revised a bit for a simpler look. Plate / walls split into two parts. More elaborate surface finishes and material selections are also used.

Second prototype in white with a rose-gold knob and polycarbonate walls.

Second prototype - E-White with Rose Gold PVD and polycarbonate walls

Second prototype in dark grey with a silver knob.

Second prototype - dark gray ano with Silver PVD and aluminum walls

Second prototype in dark anodised aluminium with an aluminium knob.

Second Prototype - dark ano with aluminum knob and walls, Silver PVD plate

Second prototype in glossy white with rose gold, outdoors.

Second Prototype - e-white with rose gold.

I plan to change the glossy e-white shown in this proto here with a matte e-white for the production version.

Turntable knob

I went on to also design a turntable-style knob, which can be used in place of the normal knob, this would be intended for usage as a Beatmania mini-controller.

Render of the Solo with a rose-gold turntable-style knob.
Render of the Solo in silver with a turntable-style knob.
Two Solo units on a desk, one fitted with the turntable knob.

IRL picture of the turntable-style knob. There is a video of me demoing it here: youtube.com/watch?v=LR3YRxOkG0Q

Synth Labs Solo - beatmania IIDX Ultimate Mobile demo

The PCB

I made an effort to route the traces on the PCB artistically. Since this product is one that I expect users to open up (if they change from P1 to P2 orientation, or want to change keyswitches or something), I want the internals to look as beautiful as the externals.

PCB layout, top side.
PCB layout, bottom side, with curved traces.
The gold-finished PCB with clear solder mask, standing beside an opened unit.

To help show this off, I had the PCB manufactured using an ENIG (immersion gold) surface finisher, and clear soldermask. I'm quite happy with the result!

You can also see in this photo, at this point I've added custom form-fitted acoustic foam inserts. They help improve the sound and feel of the macropad.