My Mega ST 4 "High" machine runs on a modern replacement power supply, the STPSU from CenturionTech. I went for this because the original PSU is aging, and a modern supply delivers far more stable power, which matters especially with the ET4000 graphics card drawing from the 5V and 12V rails.
Why a new power supply
The original Atari PSUs are decades old now, and their output rails can drift, ripple or sag under load. A highly upgraded machine like the "High" with its MonSTerBoard, IDE storage and ET4000 card draws more current than a stock ST, and a clean, stable supply avoids the crashes and instability that can come from a worn-out PSU. The STPSU is a drop-in replacement designed specifically for the Atari 520/1040 STF/STFM/E and Mega ST machines.
STPSU features
- True plug-and-play, a complete drop-in replacement, no modification to the computer needed.
- 230V and 110V AC, works on both power networks.
- Efficient switched-mode design, very low heat dissipation.
- High current output, supports heavily upgraded and modified configurations.
- Stable, low-noise output, in all working conditions.
- Zero noise design, no heatsink or fan needed.
- Extra on-board output connector, to power additional devices.
- On-board LED indicators, for operational status.
- Safety features, thermal shutdown, short-circuit and over-current protection.
My Setup
In the Mega ST 4 "High" machine the STPSU provides clean, stable power to the MonSTerBoard, IDE storage, the ET4000 and the rest of the workstation, keeping everything running reliably.
Gallery
The STPSU replacement power supply from CenturionTech.
The STPSU board detail.
The STPSU ready for installation.
Manual and documentation
CenturionTech provide a user manual PDF. Since such documents can disappear from the web, I've also kept a local copy of the manual (version 1.01) in this project:
Download the STPSU User Manual (1.01) here