There are a few things to consider when getting a power supply for a Eurorack video synthesizer. Power supply noise is more of an issue with video than it is with audio. Some switching supplies will produce noise that is not audible, but can be visible, manifesting itself as unstable periodic lines. A linear power supply won’t have the same high frequency noise as a switching supply, but they are heavier as they use transformers.
A list of recommended power supplies can be found here
Other available power supplies might be suitable for video, but the ones listed in the link above are ones that LZX has tested and found to work well with low noise.When choosing a power supply you have to consider the size of the system you already have, or the size you want to have. The general rule for LZX modules is that for every 1HP there will be 10mA consumption per rail. Power suppliers have different output current ratings for each rail. So for example, for an 84HP system consumption should be around 840mA. This is not a hard rule, and some modules may consume more or less mA per HP. All of the current consumption specifications are on each modules individual product page. It’s good practice to allow for some headroom on your PSU, something like 15% should be good, preventing the PSU from being worked too hard, as performance decreases as the power supply comes under more load. So for a theoretical 84HP system a 1000mA PSU should be sufficient (but please tally all actual current consumption specs for the individual modules to be in the system). Remember to check the per rail specifications of the module consumption and output power supply.
Some LZX modules need to be on the same power buss as the sync generator to function properly, such as the Castle VCO. These modules take their sync signals from the power buss so if they are being used in your system remember to put them on the same buss as the sync source.
If you keep these considerations in mind you can achieve a low noise power scheme for your video synth system.
Admin note: Original post by Phil Baljeu on the former LZX Knowledgebase