I am interested to update my 15 year old system !

Hi Everyone, Thanks so much for the input thus far ... it has already had a big impact on my thinking. I felt a bit overwhelmed with all the choices I had to make, and this has already put me into a prioritized direction.

I will put off the expansion into vinyl for now. It seems from all those with good experience in vinyl that it is a long journey, and expensive ! I have no vinyl now, so it means a focus not just on equipment, but building up a collection of vinyl - which seems like its own full time job getting this right. So I will deal with my digital upgrades first.

I will start auditioning speakers to the best that I can. I was still intrigued with Zu from what I have read, and the suggestions above on Harbeth seem very good based upon my research into the brand just now. There is a dealer not far from me who handles Audio Note, which also seems to be a solid choice.

A QUESTION ABOUT STREAMING ... If I am now streaming from Qobuz through the Bluesound Node, should I expect that source to be as good as the Apple lossless files on my Mac? If they are both high res digital bits coming in to my DAC, is there a reason they should sound different - one better than another ?

Also - why would a high end streamer sound better than a Bluesound Node ? Again - if 2 different streamers are pulling a digital stream from Qobuz - and both are feeding the same DAC - would the streamer affect the sound ?

PMM SUGGESTED GETTING MY LEVINSON CHECKED BY A TECH. As long as it is playing well, what could be needed if it hasnt been used for several years.

And finally - the power regenerator replacement I will also make a lower priority as I focus on the speakers and digital source. I will also try to get some ideas on cables - but obviously - that comes after a speaker change !

Thank you all - and would still appreciate any input based upon my comments here and what I suppose will now be my first priority of looking into speakers, and whether the Bluesound Node (although new) should be replaced with something better.

Really appreciate all the help !

The albums you have stored on your hard drive as Apple Lossless (ALAC or AIFF I assume) may not always be the same versions of those albums you would stream from Qobuz. Original in AIFF vs. remastered and or high res on Qobuz for example. 
 

As to the difference between streamers, some of the driving factors would be better quality of parts, better designed and isolated interfaces, better power supply (linear vs switch mode, type of transformer and filtering, etc.) and a better implementation and integration of firmware and hardware. 
There are DACs available on the market that include network renderer either as an option or a standard feature, that makes them Roon ready. That eliminates the need for a streamer, interconnect cable between streamer and DAC and possible power related upgrades you can get sucked into such as external power supplies, power cords, etc. Roon is a subscription based music management service that consolidates your stored music and your streaming services into one platform. It requires you to run Roon Core on your computer and a remote app on your mobile device. You can also use Roon with pretty much every major streamer today with some exceptions, i.e Aurender. 
The network renderer in the DAC typically costs less than a dedicated streamer but in some cases beats out a separate streamer and DAC combos of comparable cost in performance. 
 

All these differences between digital sources will very in degree depending on the quality and price range of the source component(s), the rest of your system, synergy and your ability to hear and identify these differences. 
 

As far as the amp goes, if your Levinson integrated works and sounds fine, I wouldn’t bother getting it checked out by a tech. Just use it you like how it sounds until you are ready to upgrade.
 

@vonhelmholtz 

 I agree with you on the value of digital vs analog equipment.  With digital a relatively small investment will get exceptional results.  It tends to get better as you spend more but the ceiling is easily obtainable. An equivalent amount spent on analog usually leaves you lacking in some areas.

   I disagree with you re PS Audio.  Their issues started well before the pandemic.  Their attitude is: Thanks for buying our stuff, it shows that you are a discerning consumer.  It broke?  Sorry man, we are a small company, and it is your responsibility as an audiophile to keep us going, so here is the replacement which costs 3x what you originally paid and might last half as long.  Watch our YouTube channel!

  If they are now blaming the pandemic for their issues, that is a convenient cop out

@markny2011  The reason that I recommend you take your ML amp to a tech, was that it may be good to have those capacitors checked. Would also help on resale if you decided to go that route.

@pmm it would not help the resale in any way. If it works, use it if you want to keep it, or sell it in working condition. If it doesn’t work, figure out next steps. 
Don’t fix it if it ain’t broke. Doesn’t add value no matter how you twist it.