VSTiPiano

After milling the slots for the screen and controller assemblies, it is time for finishing the top plate with Warnex. 

The backside features an engraved plate with various connectors:

The 8 VST channels are controller with an illuminated button. To accomodate the limited space and meet my specific requirements, I decided to create a custom solution.

The same PCB is used for the 8 menu buttons on the left side of the LCD screen. These PCB's were manufactured in China. The quality is not always 100%, as you can see in the following image:

The traces where cut and corrected manually.

Another slightly larger PCB is designed to accommodate 8 sliders:

The PCB's are mounted with plastic bolts:

The PCB are mounted in custom lasercut 5mm acrylic. The buttons for enabling the channels are slightly larger than the rows on top. Their intended functionality is as follows for each channel:

• Edit: Opens an effects page on the screen for the VST channel.
• Alt: Selects between presets for that channel. For the EP channel, this could include instruments like a Wurlitzer or Rhodes, for example.
• Zone: Determines the active keyboard zone for the channel, selected by playing the upper and lower keys for that zone.

The result looks pretty neat:

After putting it all together, it was time for the first test run and to tweak the responsiveness of the keys.

I created a small tool that helped me fine-tune the velocity curve, which I could then import into C for the scanning interface.

I was really happy with the first result:

For the computer, I chose a mini-ITX Gigabyte B560I AORUS PRO with an Intel Core i5-11600K, 16GB of 3200 DDR4 RAM, and a Noctua NF-A12 fan to ensure silent operation.

Two 9cm be quiet! fans were recycled from the VSTiBox for airflow in the cabinet. The concept involves air being drawn in through the dual 9cm fans as the inlet. Subsequently, the air travels through the mini-ITX stack and exits the cabinet at the rear of the PSU.

After creating a preliminary 3D CAD sketch, I measured the precise dimensions of the cabinet by positioning the keybed and mini-ITX on the bottom plate.

The cabinet is constructed from plywood, coated with two layers of Warnex, a material commonly used for subwoofer cabinets. This method has proven to be much simpler than applying Tolex, which is often used for guitar amps.

The side panels feature a slot for easy access to the aftertouch strip. American walnut side panels are then securely attached to the multiplex side panels to give it a polished finish.

The VSTiPiano project started with the purchase of the keybed: a Fatar TP/40M + aftertouch strip. 

To interface the keybed with the Windows PC, I chose to use an STM32F407 Discovery board and created a breakout for the Fatar connectors with the scanning interface.