I'm happy but I want more, more, more

Moonglum, I disagree that this is or is becoming a rich man's hobby. The thoughtful and introspective man who is a clever shopper and a little bit handy in a workshop (not necessarily a craftsman) can achieve as much or more satisfaction as anyone with purely money to blow away.  True, you have to have SOME money to spend.  But six figures, nah.

Sadly we are not all millionaires and the best analogue is rapidly becoming a rich man's hobby

I see people putting together very successful systems using modest equipment like the Technics SL1200 with a Grado Gold cartridge, amps like a Dynaco SCA-35 and a perhaps set of Lowthers. But I guess a lot depends on your definition of rich...

Dear @bill10907 : Maybe you are not sure to give an answer to my questions that were not " rocket science " knowledge level needs to do it.

Anyway here I go:

to build any audio system we must to start with the best audio components/items we can afford at both system chain link extremes: front end and speaker/room.

In between those system chain link extremes yours looks pretty decent/good.

Where can I start to up date your system?. Very simple: where the sound comes at your listening position ears: speakers.

NO. I’m not talking to change those Thiels, as a fact I loved Thiel speakers and had great opportunities to liste it for long periods of time even at my place with diferent models: 7, 5, 3.5, 1.2 and the 3.6 you own.

Well the 3.6 ( as any other speaker ) is far away to be " perfect " but the 3.6 has a severe problem and is a true limitation for that " more, more " you are asking for.
Problem is that so high crossover frequency between the woofer and midrange drivers: 500 hz that grows up in frequency due the JT preference for first order ( 6 db. ) crossover filters that permit that those woofers handle frequencies as high ( we can hear because those first order filters. ) as 700hz-800hz and this means really high THD levels on what you are listening.

Here you can read what I’m talking about ( read it carefully. ):

https://forum.audiogon.com/discussions/do-you-think-you-need-a-subwoofer/post?postid=310058#310058

when you liberate the 3.6 woofers of those long excursions from 100hz and down the improvement ( sure, true and real. ) in quality level of the sound you will be listening has no paragon: just fabolous, just a new improved audio system that you can’t even imagine you " have it ". Your system could be ( then. ) outperforms systems in the 300K dollars!. Believe it or not.

@m-db sugested that and ( independent of his reasons to posted it. ) he is spot on.

There are other areas where you system can be upgraded but those are latter and when you already integrated a pair of active/self powered in true stereo fashion in your today system.

Many alternatives for subwoofers but the true home system experts comes from Velodyne and for very good reasons: DD-15 or HGS-15 models can do it over any other " glamorous " subs in the market.

Btw, why do you think that the today bets quality level performance spekaers comes with dedicated active subwoofers?. Here you can see a " dream audiophile system " where those speakers comes with active subs:

https://systems.audiogon.com/systems/615    

but not only those speakers but for example the top Vandersteen and many more.


Regards and enjoy the music.
R.

Agree with Raul, give us more info in what specifically you're looking to improve upon.  "More" is not enough to go on to get targeted and more helpful recommendations. 

LewM said : " I disagree that this is or is becoming a rich man's hobby. The thoughtful and introspective man who is a clever shopper and a little bit handy in a workshop (not necessarily a craftsman) can achieve as much or more satisfaction as anyone with purely money to blow away.  True, you have to have SOME money to spend.  But six figures, nah."

I'm confused. Who said anything about “6 figures”, or suggested that shrewd second-hand buying wasn’t an option? The OP merely asked what could benefit from improvement in his system and he got a few answers. ;^)

Is the HiFi biz rapidly becoming the province of those with higher levels of disposable income….?

Well, that depends on who one talks to.

Some say all we must do to get good HiFi on the cheap is to purchase a second-hand SL1200 and refurbish it.

While I’m not opposed to this idea and have applied this principle a lot with cars, perhaps before we all rush off and start scanning E-Bay a simple lesson in economics might be in order. For every person who currently owns a second-hand SL1200 there is someone out there who bought one brand new then got rid of it  i.e. an undeniably larger number of original owners (because not all units made it back to market). In other words, the second-hand market doesn't exist unless the new market exists strongly.

Last time I looked the new SL-1200G (the non-Limited Edition model) was planned for 2016 release AT NEARLY TWICE THE PRICE OF THE OP’S CURRENT TURNTABLE.

So it would be truer to say that for more than half of us it is *becoming* an expensive hobby and for the remainder it isn’t. I will however put the money towards the items where I feel it will do the most good. ;^)