No. There is no such thing. I tried a high grade over built hard wired switch box… still notably degraded the sound. Pretty much why high end preamps don’t have tone controls and all sorts of functions. Touch the signal as little as possible for the best sound. The “straight wire” principal. I have been pursuing high end audio for fifty years… basic principle. No frills, short as possible gives the best sound, no exceptions.
one of the thing you have to watch out for is that, sometimes one thing will not be obviously detrimental to the sound… but they are additive. So, things you shouldn’t do… maybe pile up wires together, add a switch box, and use a regular outlet. Perhaps you can’t hear one… but the combination has a big toll. So it is important to care and tweak each aspect… ever if you can’t hear it immediately. It takes years to develop listening skills to identify really small differences. But in aggregate they make all the difference in the overall sound.