Description
The USB MIDI Wavetable Header allows you to easily connect a Wavetable module to a modern PC. The card uses a WCH CH345 USB to MIDI IC and a small +/-12V module along with a standard 26 pin wavetable header, like the one used on the Sound Blaster.
- UART based MIDI via the WCH CH345 USB to MIDI IC
- Plug and Play Support for most Modern OSs
- Standard 26-Pin Wavetable Header Pinout for Maximum Compatibility
- Large PCB Houses Most Wavetable Modules with Ease
- Selectable USB/Regulator Power for 5V-only Wavetable Modules
- Onboard module to provide +12V and -12V DC Power
- 1/8” / 3.5mm Stereo Line-Level Audio Output
- Reset / Panic button to Reset Wavetable Module
Additional Information
We designed this device for testing wavetable modules we built and thought it might be useful to others as well. There are many wavetable to MIDI adapter boards out there, but none that connect directly to USB. You can easily access all your vintage modules on a modern PC, just plug it in and use your favorite MIDI-aware software to playback files or use it as a synthesizer!
Some wavetable modules require only a single 5V DC power supply to operate, while others require three separate supplies. For example, the Little Dreamer Wavetable we sell only requires one 5V supply. We do not have an exhaustive list of boards, but in general, older boards from the 1990s will probably require not only a 5V DC supply, but also a positive and negative 12V DC supply. Newer boards will likely only need 5V.
There are two ways to provide 5V DC power to the wavetable module. Jumper J4 allows the user to select between USB provided power, or DC jack power. An onboard 5V regulator will be used if the DC option is selected and an external power supply will be required. USB power can be used for lower power modules (300ma or less) such as the Little Dreamer. Some larger 5V only modules, such as the MT32 Pi, may draw too much power from the USB port causing improper operation.
An external power supply is also required to power the onboard +/-12V power supply module. Be sure to also set J4 to use DC power when using modules which need all three power supplies.
The DC power supply needed to power the onboard module is not included with the board. A power supply from 7 to 9 Volts DC of around 1000 milliamps or 1 amp would be ideal. The power input uses a standard 5.5mm outer diameter / 2.5mm inner diameter center positive jack. Higher voltages may cause the on-board regulator to get too hot.
Here is an example of a supply that would work great with this board: 9V 1A DC Power Supply
At times, notes may hang, or you may just want to reset to the default settings. Momentary button SW1 acts as a reset for the wavetable module.
The USB to MIDI IC doesn’t need an additional driver for more modern operating systems. Both Ubuntu and Windows see the interface with no issue. While it hasn’t been tested directly on the Mac OS, the CH340 driver, which is commonly used with low-cost serial to USB interfaces, is compatible if not identical to this CH345 and appears to be widely compatible. There is a link below to the drivers which are provided by the manufacturer. There is not a driver specific to the CH345 listed, however some of these may be useful for reference or testing.
CH34x USB: Drivers
**A standard micro-USB cable is included to connect the device to your PC, but a DC power supply will need to be purchased separately to power the on-board module. We considered including one, but we could not find a low-cost universal supply which was suitable. It is a very standard jack size and voltage, so look in your junk pile. If you’re like us, you probably have one to fifteen sitting around already.
The pictured modules are not included, they are for illustration purposes only.
