Alternative that's easy and good for the PSU1

Unfortunately my mains conditioner is not a commercial product to which I could refer you.

It was made some years ago by a local fellow and I do not know if he is still making them.

I have never opened it to investigate its workings (unusual - I have opened most things at one time or another ).

My main amplifier, CDP, Tuner, buffer, phono stages and DAC & HPA supplies are connected through it.

The improvements I noted when plugging the DAC and HPA linear supplies into it as referred to above, were as you note, basically a lowered noise floor giving better separation and spatial imaging with more tonal "colour", better reproduction of vocal nuance and inflection. improved timbral definition of instruments within an orchestra and increased definition of individual instruments in orchestral crescendos - eg massed violins rather than messed violins.

While I list all the above attributes, none might be described as "night & day" differences, rather they have proven cumulative as various parts of the system have undergone improvement or tuning.  Their effect is much more noticeable now than a few years back prior to various mods, tweaks and upgrades.

Much the same as when I have modified individual power supplies in various equipment with increased capacity/better filtration/regulation etc.

I have not noticed any downside as others have at times noted with decreased dynamics, in fact, rather the contrary.  I do like my music to have visceral impact when called for and the system overall seems well capable of providing startling moments from time to time, I generally prefer a "sit up and listen to this" type of presentation to a laidback "background music" type of presentation.

Sometimes a familiar piece of music will show how far it has come, sometime after my most recent modifications to my amp I was surprised to hear something in a piece I have heard often, a recording of a Vivaldi piece for flute, bassoon and orchestra, I was only half listening and heard something and thought what is that? - it was one of the players (probably the bassoon) taking breath.  Subsequently I noticed it several times during this particular piece.  This was on speakers, not headphones.

Lapkwan,

there is nothing particularly original about any modifications I have made.  Most of them are well documented on various threads on various forums related to the particular equipment in question.

I like to tinker and have some basic electrical knowledge (and friends with more).  If I see a particular modification that interests me then I will try it if opportunity arises.  If I hear a particular problem, I will try to determine its possible cause and try various things to address it.  Sometimes successfully, sometimes not.