Best 15 kHz to 31 kHz DVI Arcade Upscalers

Classic arcade hardware typically outputs standard-resolution RGB video at a horizontal refresh rate of roughly 15 kHz, which is incompatible with modern monitors and flat panels designed for 31 kHz (480p VGA/DVI) or higher frequencies. This article breaks down the leading hardware upscalers and line-doublers capable of accepting low-resolution 15 kHz arcade signals and outputting clean, low-latency 31 kHz digital video through DVI interfaces.

The 15 kHz to 31 kHz Challenge

Original JAMMA and arcade PCBs generate an analog 15 kHz horizontal sync signal (approximately 240p or 480i). To display these signals on modern high-resolution monitors, arcade cabinets with digital panels, or DVI-compliant CRT multisync monitors, the signal must be frequency-doubled to 31 kHz (480p). Because arcade video often features non-standard refresh rates, unusual sync combinations, and higher signal voltages, dedicated upscaling hardware is required to stabilize the image without introducing input lag.

Top Upscaler Devices

1. Open Source Scan Converter (OSSC)

The OSSC is one of the most widely used devices for arcade and retro gaming.

  • Video Conversion: Rather than relying on a slow frame-buffer, the OSSC acts as a line multiplier. It takes a 15 kHz input and line-doubles it directly to a 31 kHz (480p) signal with zero input lag.
  • DVI Output: Early hardware revisions (v1.5 and earlier) feature a native DVI-D output port. Revision 1.6 and later use an HDMI port, but it natively outputs an uncompressed DVI-compliant digital video signal that can be routed to any DVI display using a simple passive pin adapter.
  • Arcade Compatibility: It natively supports RGBS (SCART, component, or raw arcade sync pins) and can handle the sync fluctuations typical of arcade PCBs.

2. Micomsoft XRGB-3

The XRGB-3 is a legacy Japanese upscaler explicitly engineered for PC, arcade, and console hardware compatibility.

  • Video Conversion: In its dedicated "B0 Mode," the XRGB-3 functions as a pure line doubler, taking 15 kHz signals and converting them to 31 kHz at virtually zero lag.
  • DVI Output: It features an integrated DVI-I output terminal. This port supports both digital DVI-D and analog DVI-A signals, making it flexible for connecting to modern digital screens or legacy computer monitors.
  • Arcade Compatibility: It features a front-mounted Japanese 21-pin RGB port and rear D-Terminal/component ports capable of interpreting raw RGBS arcade video, provided the signal levels are properly attenuated.

3. GBS-Control (Custom GBS-8200 / GBS-8220)

The standard GBS-8200 series arcade converter is a budget board notorious for poor default firmware. However, when modded with the open-source GBS-Control (GBSC) firmware and an ESP8266 microcontroller, it transforms into an exceptional upscaler.

  • Video Conversion: It reliably doubles 15 kHz RGBS arcade inputs into stable 31 kHz 480p, 720p, or 960p outputs with minimal lag (approximately 1 frame or lower depending on motion-adaptive deinterlacing settings).
  • DVI Output: Native GBS boards output 31 kHz analog RGB via a standard 15-pin VGA (D-Sub) connector. To obtain a digital DVI output, custom GBSC builds integrate an HDMI/DVI transmitter board, or users can employ a zero-lag VGA-to-DVI-A/DVI-I active converter.
  • Arcade Compatibility: The board specifically includes a 5-pin RGBS terminal designed directly for JAMMA arcade wiring harnesses, making it the most cost-effective solution tailored natively for arcade hardware.

Key Connection Considerations

  • Voltage Levels: Standard consumer video utilizes ~0.7V peak-to-peak RGB signals, while raw arcade PCB video often outputs signals at 2V to 5V. When connecting directly to sensitive scalers like the OSSC or XRGB-3, use a breakout board or harness containing 75-ohm series resistors to step the voltage down safely.
  • Sync Compatibility: Arcade hardware outputs composite sync (CSYNC). Ensure your chosen scaler supports negative/positive CSYNC and can separate or stabilize signals where horizontal and vertical sync pulses are combined.