Fine tuning the system. Where do you start and how do you proceed ?

You seem to have no major issue with the current system.  What exactly do you think could be improved.

  My suggestion is to make sure that you have a comfy listening seat, and adult beverage of your choice, and play music with obsessing about what small differences in sound are possible 

Good suggestion....

1. Keep it simple. look to simplify your system, not complicate it. I like to keep the signal path as simple as possible so I don’t add components. avoid widgets that promise magical improvement. Use good compaonent and good materials. I upgrade wires (not cables) and connectors more than components.

2. Don’t make changes based on reviews and recommendations. Follow the money and you realize that some very compelling words are written to sell you things. Make changes because you understand what you are trying to do and you think the new component will do it. Don’t try to solve problems that don’t exist just because a dealer or a reviewer suggests it.  You may have to do weeks or months of research to understand a change you are considering.

3. Tube rolling is fun and can be fruitful. However, don’t expect miracles. there is a good chance the tubes that are in it are there for a good reason. I just spent several hundred dollars trying different driver tubes and decided to stick with the ones in it, although a different pair of the same tubes. I am still searching for a special variety of this tube. I don’t consider this wasted money. then next pair of tubes, the output tubes, can be several thousand dollars to do tube rolling.

4. Crossovers. most speakers have crossovers that use poor components compared to the price of the speaker. upgrading your crossovers is a fertile ground. I’ve had very positive results. Again keep it simple. Not a beginner DIY project. You’ll need a friend who understands electronics as it isn’t as simple as choosing better components of the same values.

5.Patience. from your posts I don’t think that this is your greatest virtue. Move slowly, do lots of reading, make your own decisions. when you do make a decision, sleep on it and be self critical before making a change.

Jerry

Start by assessing what you like about the sound you are getting and what improvements you want.  Keep in mind that anything that you do, if it is at all effective, alters the sound and that can be for better or worse.  Be prepared to accept that something you do might have to undone.  I am amazed at how many threads talking about power cords, interconnects and tweaks have very little comment about changes that were detrimental when there should be a lot more instances where a change in sound went the wrong way.  It helps to be more open minded about one’s own purchases.  
 

With tube gear, I would start with trying different tubes based on commonly shared experiences reported about tubes.  Some tubes are warmer sounding, or more dynamic and detailed sounding, etc.  I would start with the cheaper tubes, which tend to small signal input and driver tubes.  Even though they can be much more expensive, consider vintage tubes—many are much better than current production.

Interconnects and speaker cables would be next for me; they tend to make a bigger difference than power cords.  But, if you are using the cords that came with the gear, junk that and go with something a little better before searching for the ultimate set of power cords.  You will hear differences between very good chords, but that difference is comparatively subtle and more evident when you have dialed in the rest of your system.

Vibration damping/control via specialized racks, equipment footers, etc. can have substantial impact on sound and I personally find it is easy to overdo this and end up going the wrong way.  Sometimes you don’t even know you goofed until you pull all the stuff out and find out that you now like your system more.

I roll tubes I've rolled cables a little bit of isolation and things sound pretty good here. It's really about trying things and then living with them. Don't jump to immediate conclusions I usually take at least a month to get my head around changes and it becomes more of a vibe thing can I relax into the music or not.