The DC1 is a DC filter to be used with switched power supplies in eurorack cases. It is used to remove ripple on the power that otherwise can find its way into the audio of your modules or mess with the logic in digital modules.
The DC1 is a dual passive first order filter that can handle up to 5A on both the plus and minus 12V power rails. It shall be placed between the switched power supplies and the busboards of your system.
If you calculate that you have 1A of power for each row of 84hp in your case this filter can handle at least 4 rows of power. If you think about power this way when building your cases, you will basically be able to put any combination of modules into your system without any problem with power. You should always have a little bit more power available in your system than you think you need. Some 25% extra is a good margin.
Switched power supplies typically have a switching frequency of about 100kHz. The 100kHz ripple on the power rail is usually fairly easy to filter away. Can be fixed with a physically small filter even at fairly high power.
It can be a bit trickier with the regulation loop frequency rippel. That rippel can be in the region of 1kHz to a few kHz, that is right in the audio range where you don’t want it to be.
As the regulation loop frequency is so low bulkier components are needed, especially when you need quite a bit of power.
The DC1 filter is designed for a worst case scenario of a regulation loop frequency of 1kHz on the power supply. Most switched power supplies are specified to have about 100 mV of rippel out.
The DC1 is designed to attenuate that rippel on the power at 1kHz by 35dB. This is absolutely good enough for audio equipment applications.
As most power supplies have a regulation frequency higher than 1kHz the rippel is actually attenuated more than 35dB. See filter curve below.
Device specs
Module size: 83 x 57 x 19 mm. Weight 65 g.
Power requirements: +/-12V. Max current 5A but max 4A is recommended.
Voltage drop over the filter: Max 0,2V at 5A current.