Burn in will not turn a Sow into a Silk Purse .. it will not turn a $199 dac into a $10K state of the art performer
What ever the original sonic characteristic of the component is burn in will not change that
What does improves with burn in is .. Dynamics .. treble and bass become more extended ... midrange always sounds very congested like your talking with a cloth pin on your nose ... this will improve and the sound stage sounds congealed like a ball in between your speaker ... most enjoy a good center fill ... but the congealing sounds as if everyone is playing shoulder to shoulder with no space in between them like you are on a crowed subway car ... this will also come to pass with time and the sound stage will open up and spread
Some claim things get warmer but I think that is the annoying midrange congestion going away
One of the easiest ways to accelerate break in is to use a Purist Audio Design break in disc ... run the disc as prescribed for 6 cycles or about 7 hours continuously and it will get you most of the way there ... if you listen to the test tones when you first play the disc they will sound obnoxious but at the 5 hour mark you will hear the test tones sound much cleaner and distinct
A side benefit to running the PAD disc is it will cause the insects
and any small rodents to vacate the space
As far as cryoing .. I found it a mixed bag .. I've had ICs S/Cable Power Cords .. Outlets .. Fuses and RCA and speaker binding post connectors done
I every case the effect was immediate and perceivable .. it makes the presentation sound dead silent ... a very eerie type of quietness ... like walking into a library .. the silences is deafening ... but it is also dull and dumbed down lacking in something that just draws you into the music
Less fill or more taste .. your chose .. I think there are other ways to reduce the noise floor that don't effect the presentation ... JMO