How to add a power switch to front panel?

[EarthTone]

It shouldn't matter.
However, it depends on the PSU's behaviour when unloaded.
If it goes in "hiccup" mode, there is a constant start-stop cycle that results in transients. If the filter is connected, it results in spurious currents that may radiate into adjacent equipment.
As a precaution, I would wire the switch "before" the filter.
But as a researcher, I would investigate both possibilities.

Cool! Thanks. I may try both, just trying to save time doing it the right way as I don’t have a lot of it to devote to DIY! On your recommendation I’ll try interrupting power before the filter first and see how that sounds. Thanks again.

 

[shot]

I've built two units in my studio (PRR176) that use external power supply with a switch that is located on front panel of the unit. Well, I should say they are "semi-external" PSUs since only torroid is located externally and the rest (diode bridge, regulators, caps, etc.) is inside the unit.
This was DIY so I did it with what I had around.

I took an old phone charger that provided 5Vdc. Hooked it up inside external chassis (where torroid transformer is also) and that thing is always on when mains is on. I took it's negative and brought it to the front panel of the unit to a switch and then back to external chassis. This little thing, when on, engages a relay that switches mains to the primary of the transformer. Obviously, the relay is a chunky one that can handle european 230vac without problems. And I've used a multipin connector on both external box and back of the unit to carry this signal plus all other AC signals from the torroid secondary (2x16vac, 1x18vac, 1x120vac and earth). I made sure that there's a connection from mains earth to the chassis of the external box and unit's chassis, just as there would be if entire PSU was internal. This is important! And I've also included fuse inside external box before the transformer primary. No unit should be without mains fuse!
Not sure if this thing breaks some rules but it works.

I don't worry if small phone charger PSU dies since a have a bunch of spares and it can be replaced in about half an hour.
Must mention that I also have mains switch for all my racks that I turn off when I leave my studio, so it's not 24/7 operation!



Luka