Drop-in replacement for the VSU-100

The first replacement speech synthesizer for the Stern VSU-100 (Assy A-720) in 40 years!
Built with modern components, it provides clearer, more consistent sound. The VSU-2 is not dependent on the hard-to-find TSI S14001A decoder IC, does not require changing ROMs, and is compatible with the original game connectors.

*US Domestic Shipping (USPS) and Handling $8. 8% sales tax on NY orders.
International orders, please contact us directly.

Support for all 6 original games

  • Flight 2000
  • Freefall
  • Lightning
  • Split Second
  • Catacomb
  • Orbitor 1
  • Plus Gamatron (experimental)

Additional memory space for custom speech ROM files is provided, and can be programmed over a serial connection. The source code and documentation for the programming tool are available at the pyVSU Github

Recorded audio comparison

The following audio samples compare the VSU-2 and VSU-100 during Flight 2000 game start

Original VSU-100
VSU-2 replacement

New advanced features

Volume control
It is now possible to adjust the speech volume independent of overall sound, and lets you find the right balance for your game.


Diagnostic LEDs
A +5V power LED lets you know power is connected properly. Orange indicator LEDs display the current word playing back from memory to let you know the command was received.


Game select switch
A 4-position DIP switch allows instant selection of game from memory. Supports all 6 games which originally used the VSU-100, plus Gamatron, and additional custom ROM files.


Programmable over UART
Custom speech ROMs and custom speech pitch adjustments can be programmed over UART with our open source software.