What is my next step to a better sound ?

Your base system is a wonderful system. I see two maybe three areas where there may be problems with sound reproduction. 1) CD Transport, 2) DAC, 3) Room

The inexpensive CD transport you are using is an issue. I have compared many transports into the same DAC/system and there are widespread differences in the sound. You should borrow better transports and hear the differences.

The DAC also made a major difference to me. I have also compared many DACs and they really do make a major difference. The power supplies in the DACs are the major weak point. The Analog output portion in DACs are similar to pre-amps and if the power supplies are not really beefed up, they will not sound good.

The room may require major corrections for bass or mid level or high frequency sound corrections and reflections. My main problem in my system is the room.

As a side note,you do not need to purchase stupidly expensive CD transport or DACs. There are some out there used that are incredible. For example, Pioneer Elite's DVD 09 CD players is one of the best constructed and wonderful transports (not CD player) that I have ever heard and I have compared it with many other much more expensive transports. It is built like a tank and seriously overbuilt. The Digital output of this unit rivals the best out there and you can get one for a steal used.

The used Theta DS Pro-Gen V DAC is wonderful and is very hard to beat by other DACs and relatively inexpensive used.

I have had many come by my home to hear their music on this transport and DAC combination and they left with jaws open.

People upgrade DVD players because they want newer bells and whistles, such as HDMI outputs. However, if you are using it solely as a CD transport, then wow!

I have compared them with newer more expensive DACs and CD player/transports and again, pioneer elite in the day was the state of the art in many areas. Don't overlook this relatively inexpensive but definitely high-end used combo.

There are others out there also, but find a friend or shop that is willing to let you borrow a demo CD player and/or DAC and to take it home for a week or so to listen, then make an informed decision.

enjoy.

As an owner of a set of WP 5.1's (albeit with WP8 drivers and parts) and as a former owner of ML gear.... my suggestion would be to ditch your current digital (yes, that includes the transport) and buy yourself a great CDP. Though I rarely like to plug gear that I own on the forums, I'd strongly encourage you to get an AMR CD777 and be done with it.

"It's like putting a VW GTI engine in a Porsche 911 Turbo".
Right. But if on the other hand you put Porsche Turbo engine in VW you will be dead in no time.
On the subject. Yes, of course this digital front end begs to be upgraded. Possibly cables too but I can't be sure.
Thansport is very important, sometimes probably just as important as DAC or even more. And the connection between them.
How much are you prepared to spend? How about older CEC belt drive transport(get the new belt) and Dodson DAC or something like that? Or older Sony top of the line SACD? Many to choose from, in fact.
I wouldn't touch Levinson/Wilson for now if ever.

The thing that bothers me about the Rdac is the name. It seems to be designed to capitalize on Arcam's use of the highly acclaimed DCS ring dac technology in one or two of their legacy devices, but that is not what is used in the rDac. Their web site references the relationship with DCS and the use of other DCS technology in the rdac, but not the ring dac itself which I believe is DCS's crowning achievement.

I do not think it is good business strategy for DCS to license their bread and butter technologies to companies offering products at a fraction of the cost. That's probably why the Ring DAC is not available in any Arcam gear anymore.