how to further quiet power supply of cd players

I like my all in one Lexicon RT 20 and use excellent power
conditioning with it in my Spectral system, which has made stunning improvements. Now would like to address noise inside the unit if possible.
It allows turning off video section which significantly improves audio.
Can I do something else? Thanks. Pete
Your RT20 appears to have a large ferrite core placed right after the power inlet ...

I am not a fan of ferrite cores and removed the two that were in my Exact Power EP15 from the factory .. immediately the treble opened up and sounded more relaxed and natural

Another negative experience I had with ferrite cores is when I placed some very expensive Versa Lab split Red Roller on my ESP power cords ... the sound became thinned out and lean

I would remove that big core from the inside of your RT20 and see if it doesn't open up the player's presentation as the first step

Two other things you can apply to the inside of your player that should bring some improvements are Line Rated X type caps across the line and neutral ...and a Audio Magic Pulse Gen ZX

The X caps must be LINE RATED and sized properly and should trap and dissipate some of the common mode noise traveling on the line that has sneaked by your power conditioner or possibly picked up by the power cord you use to connect the RT20 to your out board power conditioner

There are also Y rated caps that connect between the Live and the ground and the Neutral and the ground .. but they may cause issues as shunting noise to the ground could put it back on your chassis ground and eventually find it's way back to the RCAs which are tied to the chassis ground

Keep it simple and just use the X caps as I believe there is more Common Mode noise for X caps to dissipate than Differential noise for the Y caps to dissipate

Check out the link on the Audio Magic for additional info ... your RT20 generates and balloons RF into the surrounding areas of the interior of the player .. the Gen ZX generates a signal that is equal in amplitude and frequency but opposite in phase and couples to the ballooned RF your player generates and cancels it

The first Gen Zx I installed in my Denon player had immediate and positive results ... it dropped the noise floor without any adverse effects ... next I tried one in my Exact Power EP15 which is a very digital machine in the way it recreate the wave ... but was not impressed and had to struggle to hear any improvement .. this surprised me as I felt the EP15 and all it's digital circuitry was very noisy and would show noticble improvement with the addtion of the Gen ZX

The Gen ZX had no negative effect on the EP 15 as the ferrite I removed did .. but any improvement didn't jump out at me

I also tried the A/M Speaker Enhancer's which is basically a ZX for your speaker cables ... but instead of treating the RF that is air born inside your player ... the Speaker Enhancer's mount directly to the speaker cable

I ran it in and then tried placing it in the middle of the cable and tried it at both ends of my speaker cables (Ridge Street P!!!'s) and found like anything I've tried that messed with the magnetic side of the wave ... it leaned out the presentation and narrowed the sound stage

IMO these products ... Ferrite .. Shaki and the A/Magic Speaker Enhancer's are best placed as far away from your equipment as possible ... JMO

One more thing that just came to mind and will most like likely garner me a poke in the eye with a sharp stick is .. try a premium fuse in place of the stock one ... I use the older HIFI ones and understand that the newer Supreme's are a step up .. or you can use a less expensive Ceramic Body Slow Blow from Buss or any other fuse mfger like Little Fuse .. much cheaper and gets you most of the way there that the big boys do

Now I have a question ... Do you think Tinsel should be included in the Periodic Table (;-)